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Shells: User's Guide

1. assignment Part Ill POSIX and Korn Shell Command Reference 24 23 FINAL TRIM SIZE 7 5 in x 9 0 in 24 let Example x 1 let x x 1 In this example x is set to 1 then incremented to 2 using the let command If the expr command had been used a new process would have been created Also with let the is not needed to obtain the value of x read x y 14 if x gt y then echo greater or equal else echo less fi This script reads a value from the user compares it to 14 and prints an appropriate string based on the comparison Using around the expression replaces let x gt y which must be quoted to allow blanks and prevent the gt from being interpreted as an I O redirection Again the is not needed in front of x or y to obtain their values 24 24 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in print print Syntax 24 print Rnprsu n arg wee The Korn Shell print command provides the same functionality as the echo command for shell output It prints the specified args dependent upon the option set A description of the options follows R Ignore all echo escape sequences except n n Do not add a new line to output Similar to including c in arg p Write output to the process spawned with amp instead of standard output r Ignore all echo escape sequences s Write args into the history file un Write
2. 22 The job number is displayed between square brackets marks a job as the current job and marks a job as the previous job Done or Running or Stopped indicate the current status of the job In this example 1p processes is the actual command line and is telling to the system to print the processes file to the line printer Suspending Jobs Job control is supported on Series 300 and Series 800 For HP UX release 6 5 7 0 8 0 and beyond you can suspend jobs Suspending a job enables you to stop in the middle of a process and regain control of your terminal for other work Later you can resume the job or put it in the background Suppose you type in a command line and press Return but immediately realize this process takes a long time and you need to print another job If the current susp character is set to Z see stty 1 you can suspend the current job by pressing cTRL This stops the current job and returns control of the terminal to ksh Note You can set the susp character to Z by typing stty susp cin Z Return 22 2 Controlling Jobs Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The du command reports the amount of disk space used by the specified directory or the current directory if none is specified as in the following example This command then pipes the output into the sort command to be sorted and then finally redirects gt the final output to a
3. Delete line Cancels the command Insert line Translates the readable softkey command line to the equivalent HP UX command line Delete char Deletes the character under the cursor Insert char Toggles between insert and overwrite modes Recalls the previous command from the command history buffer Recalls the next command from the command history buffer Moves the cursor left Moves the cursor right am Home Moves the cursor to the beginning of the command line aii Come Moves the cursor to the end of the command line a If no insert line key is present performs the insert line function Otherwise if no elp softkey is present performs the help function Otherwise performs the normal tab function Gre Moves the cursor to the beginning of the previous word CROO Redraws the lower lines of the screen and restores any necessary terminal modes Part IV Key Shell Getting Started With Key Shell 26 13 FINAL TRIM SIZE 7 5 in x 9 0 in 26 26 The following example shows how to edit a command line 1 Select the Print status softkey on the third bank of top level softkeys 2 Select the all info option 3 Suppose you now decide to select the scheduler info option instead Press or Shift Tab to move to the beginning of the word all_info then press Clear line to clear from the curso
4. Now when you are ready to test the program you need not exit the editor which we are assuming is vi run the program see the output then enter vi again to make changes Rather there is a more convenient way to debug save the program using vi command w run the program from vi by using the command script arguments The command executes commands in the shell outside of vi When you see the output you then go back to vi when prompted make any necessary changes and try it again You can also execute a shell from vi by typing sh then execute the script For making this process quicker you can add the cat statements in the program save the program run the program from vi return to vi and use the u undo command which will get rid of the cat statements as long as you do not execute any other text manipulation commands since the last insert Part I Bourne Shell Programming Tips 7 1 FINAL TRIM SIZE 7 5 in x 9 0 in Another suggestion is to use the tee command instead of cat tee will transcribe the standard input to the standard output and makes a copy in a file s which are arguments to the command The format is tee 4 a file wee where the i option ignores interrupts and the a option causes the output to be appended to the files rather than overwriting them More than one file can be specified Creating Optional Pieces in a Pipe There may come
5. The specifies the number of the characters in the parameter is to be substituted If parameter is the number of positional parameters on the command line is substituted If the parameter is an array name with elements or and the array name is preceded by the number of elements in the array is substituted 19 10 Substitution Capabilities Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Command Substitution This substitution method is used to replace a command with its output within the same command line The standard syntax for command substitution and the one encouraged by POSIX is command 19 For example echo The people currently logged on the system are n who The people currently logged on the system are mary console Sep 11 09 01 michael tty09 Sep 11 10 35 In this example the who enclosed in is executed and printed out within the echo command line The n provides a new line The POSIX and Korn Shells implement this substitution capability using both the Ccommand form and the back quotes form For example echo The people currently logged on the system are n who The people currently logged on the system are mary console Sep 11 09 01 michael tty09 Sep 11 10 35 The second form of the command substitution command is the only form recognized by the Bourne Shell and should be used in scripts that may be run by POSIX Korn and Bourne Shell P
6. set path bin posix bin usr bin the value of the environment variable PATH also becomes bin posix bin usr bin note the difference in syntax between the two variables The commands set and setenv can be executed interactively from a terminal or they can be placed in the cshrc or login files The cshrc Shell Script File Whenever a C Shell starts during your session it searches for the file cshre in your home directory and executes it if it exists The information in this file is used to set variables and operating parameters that are local to the shell process Since every C Shell created executes this file it is customary to use it for setting shell variables by including set commands in the file If the cshre file does not exist in your home directory HP UX spawns C Shell using default values for needed variables 10 6 Preparing to Use the Shell Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 10 To verify your current shell environment execute set A listing similar to the following is printed on the display 25 set argv O autologout 15 cwd users login_name history 15 home users login_name ignoreeof ignoreeof is set for this example noclobber prompt shell bin csh status 0 term hp2622 path bin posix bin usr bin usr local bin etc users login_name 26 _ Some of the commands commonly used in the cshre file and their meanings are shown in Table 10 1 Table
7. FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Shell Scripts Introduction to Shell Scripts Simple Scripts Stringing commands together on a line with sequential processing background processing or pipes is an extremely useful tool for a limited number of commands To save typing the commands repetitively in the case where you use the same sequence of commands often you can place the command line s into a file This file is called a shell script You create a file containing the commands tell the system you want the file to be executable so it can be run as a program and then type the name of the file to execute the commands in the shell script A simple shell script could contain the following command line date who ps ef du users which executes each command only when the previous command has completed To create the script enter an editor vi for example and type the above command line Save the file To run the script you have two methods the sh command or changing the permissions on the file The sh command will create a new shell to run the script As mentioned in the beginning of this tutorial it is possible to have several shells running at the same time with the kernel in control The sh command creates a new shell to execute the file you specify if you don t specify a file it creates a new shell similar to the one you are already in To execute the script with the sh comman
8. bg break case cd continue echo eval exec exit export fe fg for function if jobs kill let print pwd read readonly return select set shift test Contents 10 FINAL TRIM SIZE 7 5 in x 9 0 in 23 1 23 4 23 6 23 9 23 13 23 16 23 17 24 2 24 4 24 5 24 6 24 7 24 9 24 10 24 11 24 12 24 13 24 14 24 15 24 16 24 17 24 18 24 19 24 20 24 21 24 23 24 25 24 26 24 27 24 28 24 29 24 30 24 31 24 32 24 33 Shells time 2 6 eee ew a 24 35 times 2 a ee ee ee 24 36 trap ee eee ee ee 24 87 typeset 2 oa ee ee ee 24 38 ulimit 2 2 a aaa ew 24 39 umask ee a a 2AA unalias ao a ee aa a 24 41 unset ooa a ee ee ee ww DAD Walt aoa a a a ee eee ee ee ee 24 43 whence 0 ee aa a 24 44 while until 2 2 2 ee 24 45 Index to Part III Korn Shell Part IV Key Shell 25 Introducing the Key Shell Introduction to Key Shell 2 2 ee ee 251 Who Should Use Key Shell 2 2 2 aa 25 4 Conventions Co ee ee ee ee 25 5 26 Getting Started With Key Shell Starting Key Shell Soe ee ee eee ee 26 1 The Default Key Shell Environment Loe ee ee ee ee ee 26 2 Key Shell Initialization 2 2 2 eee ee 26 8 Using Key Shell 2 Coe ee ee ee ee 26 4 Guidelines for Using Key Shell Coe ee ee ee ee 26 4 Using Online Help 2 2 aaa a 26 6 Entering Commands Soe ee ee ee ee 26 8 Using Visible Softkey Comman
9. 17 18 19 20 Shell Grammar Using Pipes Two Way Pipes Command Separators and Terminators Name Completion File Name Completion Path Name Completion File Name Substitution Quoting Input and Output Other Metacharacters Aliasing Abbreviating Commands Setting an Alias Tracking Aliases for Korn Shell only Exporting Aliases for Korn Shell only Default Aliases Loe ee Special Aliasing Features Unsetting an Alias Substitution Capabilities Tilde Substitution Parameter Substitution Setting and Using Keyword Named Parameters Setting and Using Positional Parameters Parameter Substitution Conventions Special Parameters Command Substitution Command lines and Command History Editing Command lines Using In line Editing Modes Using vi Line Edit Mode Enabling vi Line Edit Mode Performing In line Edits Using emacs and gmacs Line Edit Mode Enabling emacs Line Edit Mode Performing In line Edits Contents 8 FINAL TRIM SIZE 7 5 in x 9 0 in 17 1 17 2 17 3 17 5 17 5 17 7 17 7 17 9 17 10 17 13 18 1 18 3 18 3 18 4 18 6 18 8 19 1 19 4 19 5 19 5 19 7 19 10 19 11 20 1 20 2 20 2 20 2 20 3 20 4 20 4 20 4 Shells Accessing the History File 2 2 2 2 1 ee 20 5 Using the fe Command toe eee ee 20 7 Accessing the History File From vi Mode ooa ee 20 10 Accessing the History File From emacs Mode 20 12 21 Basic Shell Programming
10. 7 5 in x 9 0 in When you execute the script 2waypipe Please enter valuel and value2 12 12 23 The answer is 20 85841 it immediately executes the bs compiler interpreter which allows addition and subtraction The read statement reads from standard input the the typed numbers 12 and 12 as value1 and value2 In the print p statement the numbers are piped to the spawned process bs and summed and the sum read back into the script using the read p script Then the values sum and pi are sent back to bs and result is read back into the script using read p again Then the output is sent to standard output There are some limitations on what you can do with two way pipes m They are only useful with commands that read standard input for data and write standard output with results You cannot use commands like vi 1 which must talk to a terminal Instead use commands which read standard input and write results to standard output as soon as there is something to output m There is currently no way to close a two way pipe Therefore you cannot use them with commands such as sort 1 or pipelines which require reading an EOF before emitting useful output Instead use commands you can tell to quit Part Ill POSIX and Korn Shell Advanced Concepts 23 5 FINAL TRIM SIZE 7 5 in x 9 0 in 23 The whence Command This is a command unique to the Korn Shell When a name is provided to the whence command it returns the way in whi
11. Comments The foreach Command The if then endif Command The while Command Contents 6 FINAL TRIM SIZE 7 5 in x 9 0 in 13 4 13 5 13 5 13 6 13 6 13 6 13 7 13 7 13 8 13 9 13 10 14 1 14 1 14 1 14 2 14 2 14 2 14 2 14 3 14 4 14 4 14 5 14 6 14 6 14 6 14 7 14 9 14 9 14 9 14 10 14 12 14 13 14 14 14 14 14 14 14 16 Shells 15 16 Shells The switch Command The goto Command Supplying Input to Commands Catching Interrupts An Example Shell Script Index to Part II C Shell Part III POSIX and Korn Shell Introducing the Shells What is a Shell a POSIX and Korn Shell Versus Other Shells Features From C Shell Differences from Bourne Shell Differences between POSIX Shell and Korn Shell Definition of Terms Conventions Loe Supplementary Information Resources Starting and Stopping the Shell Getting Started Looe Login Command Line Invoking the Shell Running POSIX or Korn Shell from the Current Shell Specifying Your Login Shell Setting Environment and Shell Variables Setting Up profile and kshre Setting up profile Setting up ENV The set Command Terminating the Shell Using exit Executing a logout Script FINAL TRIM SIZE 7 5 in x 9 0 in 14 16 14 17 14 18 14 19 14 19 15 1 15 3 15 3 15 4 15 5 15 6 15 8 15 9 16 1 16 1 16 2 16 3 16 3 16 4 16 4 16 5 16 6 16 8 16 9 16 13 16 14 16 14 Contents 7
12. Key Shell allows extensive command line editing to correct mistakes You can edit either of two command lines m The readable command line that you built by using the softkeys You can edit this command line even after you have pressed to translate it to HP UX syntax Simply press the key to retrieve your softkey command from the command buffer m The HP UX command line that you typed or that appeared when you pressed Insert line after building a softkey command line keysh supports the Korn Shell command line editing modes such as vi mode Refer to the chapter titled Editing Command Lines in the The Korn Shell ksh part You can also edit the command line by using the cursor movement and editing keys found on most terminals These keys are listed in Table 26 2 Use caution when mixing vi and key editing on the same command line Key editing does not affect the vi editing mode 26 12 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 26 2 Editing Keys Key Function Backs the cursor up on the command line deleting one character at a time The available softkey options will change to reflect your position on the command line Clear display Clears the screen and command line If the screen is scrolled it clears from the cursor position to the end of the command line Clear line Clears from the cursor position to the end of the command line
13. Separator 8 2 Mixing Separators 8 2 Command Grouping 8 2 Defining Functions 8 3 Input Output 8 4 Special Commands 8 7 Exec 8 7 Expr 8 7 Conditions 8 8 Expr and Strings 8 8 Set Loe 8 9 Unset 8 11 Contents 3 FINAL TRIM SIZE 7 5 in x 9 0 in 10 Trap Hash Type Readonly Newegrp Times Ulimit Wait Return Values Parameters Set by the Shell Example Options for the sh Command Restricted Bourne Shell Bourne Glossary Index to Part I Bourne Shell Part II C Shell Preparing to Use the Shell Introduction HP UX Standard Shells Shell Startup and Termination Running C Shell From the Bourne Shell Making C Shell Your Login Shell Terminating C Shell Returning to a Parent Shell Logging Off the System Terminating C Shell with ignoreeot Set C Shell Startup Setting Environment and Shell Variables The cshre Shell Script File The login Shell Script File C Shell Termination Contents 4 FINAL TRIM SIZE 7 5 in x 9 0 in 8 11 8 12 8 13 8 14 8 14 8 15 8 15 8 15 8 16 8 17 8 17 8 18 8 18 10 1 10 2 10 3 10 3 10 3 10 4 10 4 10 5 10 5 10 5 10 6 10 6 10 8 10 9 Shells 11 Command History The Command History Buffer Re executing Events Referencing by Event Number Referencing by Relative Location Referencing by Event Text Reusing Command Arguments Modifying Previous Events An Example 12 Aliases Command Substitution Metacharacters Aliases Aliasin
14. Substitute new for old Any character may be used as the delimiters between the substitution strings An ampersand amp in the new string is replaced with the entire old string Note that this affects only the first occurrence of old on an event s command line Use the gs combination if you want the effect to be global Use in combination with another modifier to make the effect of the modifier global for an event s entire command line For example gs old new replaces all occurrences of old with new NOTE Only one substitution can be made per argument in an event For example the effect of gs joe mary on the path name users joe joe_file would be to make the following modification users mary joe_file Use only the directory path name from a specified argument in a previous event by removing its final path name component that is use only the path name s head Print the event specified but do not execute it This is useful if you just want to verify what a particular event was For example 10 3 p prints event number 3 on your terminal without executing it Quote the modifications so that no further modifications can take place Remove the filename extension If a file name s tail ends with a followed by one or more characters the and the characters that follow it are dropped thus the o is removed from filename file o leaving file Continued on next page 11 6 Command Histo
15. definition 19 4 keyword 19 4 name 19 4 positional 19 4 19 6 setting 19 6 shifting 19 5 substitution 19 4 19 7 parenthesis 19 11 21 18 parent process 17 2 passing data to scripts 21 2 PATH 16 6 16 9 16 11 18 3 path name completion 17 5 17 6 pattern matching 19 7 21 9 PID 17 2 pipe 15 6 17 1 pipeline 15 6 pipes two way 23 4 positional parameters 19 4 19 5 19 6 POSIX Shell definition 15 1 16 1 versus other shells 15 3 PPID 16 9 16 11 17 2 precedence of commands 23 7 Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in print 21 2 21 4 21 6 23 4 24 25 printing data 21 4 21 6 process 16 2 process child 17 2 process id 16 2 process identifier 16 1 process limits 23 17 process number 16 10 process parent 17 2 profile 18 3 20 2 20 5 21 1 profile 16 4 16 6 16 14 programming language 15 3 21 1 prompt 16 2 ps 16 11 17 2 17 8 17 10 22 1 PS1 16 3 16 9 16 12 PS2 16 9 16 12 17 10 PS3 16 9 16 12 21 10 pwd 18 1 24 26 PWD 16 9 16 12 Q quotes back 17 9 19 11 definition 17 9 definitions 17 9 double 17 9 single 17 9 quoting metacharacters 17 9 R RANDOM 16 10 16 12 read 16 12 21 2 23 4 24 27 reading data 21 2 readonly 23 13 24 28 recursive function 21 20 redirecting input output 17 10 redirection symbols 17 10 redirect operator 17 10 removing aliases 18 8 REPLY 16 10 16 12 21 2
16. gt do gt aif x file gt then continue gt echo file is executable gt fi gt echo file is not executable gt done 21 14 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Arithmetic Evaluation Using let let another command unique to POSIX and Korn Shell enables shell scripts to use arithmetic expressions This command allows long integer arithmetic The syntax is 21 let arg where each arg is an arithmetic expression of shell parameters and operators to be evaluated by the shell Table 21 2 lists the operators in decreasing order of precedence Table 21 2 Operator Decreasing Precedence Order Operator Description unary minus logical negation fh multiplication division remainder addition subtraction lt gt lt gt comparison equals does not equal assignment In the next example x is set to 1 and then when the let command executes a first 1 6 is evaluated to 6 m then 3 1 is evaluated to 3 m then x is added to the 6 which equals 7 and a finally the 3 is subtracted from the 7 to equal 4 Part Ill POSIX and Korn Shell Basic Shell Programming 21 15 FINAL TRIM SIZE 7 5 in x 9 0 in 21 x 1 let x x 1 6 3 1 echo x 4 You can also use parenthesis to create this effect or override the operator s precedence to produce different results 9 When using parenthesis
17. use the chsh change shell command chsh username full_shell_name where username is your user name and shell_path_name is the full path name e g bin posix sh of the shell you want as your default Table 1 2 contains the full path names for each of the shells After you use the chsh command you must log out and log in again for the change to take effect For example if terry changes the default login shell to the Korn Shell the command reads chsh terry bin ksh Introduction to Shells 1 5 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Part Bourne Shell The Bourne Shell Shell Commands Shell Scripts Basic Shell Programming Advanced Programming Programming Tips Detailed Reference Bourne Glossary FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in The Bourne Shell The Bourne Shell is a command interpreter it takes your commands and interprets them to the system This tutorial will help you learn to program the shell to make your daily work easier For example if you have to execute a series of commands every day you may get tired of typing the commands each time By programming the shell you can create a shell script a file containing all of the commands that need to be executed each day To execute the commands you only need execute the shell script This tutorial will discuss several concepts which are related to programming If you
18. word Does the same as except the shell program will be exited if the parameter is null If word is left off the message parameter null or not set is printed Example dir1 usr bin will perform the substitution with usr bin if dirt is null and then exit the shell parameter word If the parameter is set and is non null then substitute word Otherwise substitute nothing Positional Parameters When you execute a shell program you can include parameters on the command line When you do each parameter must be separated with a blank like scopy filei file2 file3 where scopy is a shell program with three parameters When the shell program runs you can access the value of these parameters each separated by a blank with positional parameters named 0 1 2 9 If your list of values exceeds nine parameters the values are placed in a buffer and you can access the values with the shift command discussed later in this chapter scopy personnel fileA has positional parameters 1 equal to personnel and 2 equal to fileA The positional parameter 0 is always the command name scopy in the example above 5 4 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in If you need to know the number of positional parameters let s say you wish to see if the user included any parameters at all you use If you need a parameter which contains all of the positi
19. 21 10 reserved word 15 6 23 6 23 7 Part Ill POSIX and Korn Shell FINAL TRIM SIZE return 21 19 24 29 returning from functions 21 19 rksh 16 12 S scripts 21 1 SECONDS 16 10 16 12 select 16 11 16 12 21 10 24 30 separating commands 17 3 set 16 8 16 9 16 12 16 13 18 3 19 6 20 2 20 4 22 3 23 1 23 9 23 12 24 31 setting aliases 18 1 setting environment shell variables 16 4 setting kshrc 16 8 setting parameters 19 4 19 5 19 6 setting profile 16 6 shell 15 3 16 1 SHELL 16 3 16 10 16 12 shell parameters 16 4 shell parameters variables 16 10 16 11 16 12 shell script 21 1 21 18 shell variables 16 4 sh_history 16 10 20 5 shift 24 32 shifting positional parameters 19 5 signals 23 16 simple command 15 6 single quotes 17 9 slash back 17 9 sort 17 1 18 1 18 3 spawns 16 1 special character 17 10 standard error 17 10 standard input 17 10 standard output 17 10 START 16 7 stderr 17 10 21 2 stdin 17 10 Index Index 5 7 5 in x 9 0 in Index stdout 17 10 subscript 19 10 21 17 subshell 16 3 substituting parameters 19 7 substitution command 19 11 file names 17 7 parameter 19 4 tilde 19 1 subtraction 21 15 suspending jobs 22 2 system structure 15 1 T TERM 16 7 terminating commands 17 3 terminating the shell 16 13 test 21 7 24 33 tilde 19 1 tilde substitution 17 13 19 1 time 24 35 tim
20. 26 18 commands custom 12 2 command separators 8 1 17 3 command substitution 5 8 12 4 19 11 command terminators 17 3 command words types of 23 7 commenting 17 13 21 2 comments 5 13 14 14 comparing shell features 1 3 completing file names 17 5 17 6 path names 17 5 17 6 components of softkey nodes 27 3 computer font 15 8 concepts Key Shell 27 1 conditional branching 6 4 conditionally executing commands 8 1 conditional statements 21 7 Master Index FINAL TRIM SIZE Index conditions 5 10 8 8 configuring Key Shell 26 15 options 26 24 saving changes 26 27 status line 26 26 undoing changes 26 27 connecting programs 3 4 continue 24 9 continue looping 6 8 continue statement 21 14 control key 9 1 20 4 controlling jobs 22 1 control structures 14 13 conventions 2 4 19 7 conventions printing 25 5 coprocessing 17 2 23 4 creating aliases 18 1 creating custom commands 12 2 creating custom softkeys 27 23 creating jobs 22 1 creating scripts 21 1 creating shells 5 2 creating your own parameters 5 2 C Shell 10 1 10 3 15 3 16 1 commands 14 1 metacharacters 12 5 12 6 12 7 12 8 12 9 12 10 overview 1 1 scripts 14 9 startup 10 5 termination 10 9 cshre file commands 10 7 cshre shell script file 10 6 curly braces 21 1 curly brackets 19 7 21 18 cursor 9 1 custom commands 12 2 customizing commands 12 1 customizing environment 16 4 customizing
21. 26 29 KEYSIM 26 29 KEYTSM 26 30 LINES 26 1 26 30 PAGER 26 30 PATH 26 30 PS1 26 26 setting 26 28 TERM 26 1 26 30 TZ 26 30 softkeys adding invisible 26 19 adding text 27 19 27 20 adding visible 26 16 attributes 27 6 backup 27 23 cancelling a command 26 14 components of 27 3 creating custom 27 23 custom 27 1 definition 27 3 deleting 26 23 disabled 27 3 display 26 2 editrules 27 8 27 9 enabled 27 3 error messages 26 5 format 27 4 Index 4 function keys 26 2 invisible 26 10 26 19 labels 26 15 menu 25 3 26 2 moving 26 23 names 26 15 navigation 27 3 node hierarchy 27 2 online help 25 3 26 6 27 21 options 26 4 26 9 26 10 parameter 26 4 27 4 selecting 26 4 string 26 4 27 4 visible 26 9 26 18 softkeys file 26 16 26 19 standard HP UX commands 26 11 starting Key Shell 26 1 status line 25 3 26 2 changing 26 26 string softkeys 26 4 definition 27 4 T TERM 26 1 26 30 terminal characteristics 26 3 Terminal Session Manager and Key Shell 26 31 text adding to softkeys 27 19 formatting commands 27 21 help 27 20 hint 27 19 required 27 19 topics online help 26 6 translating a softkey command 27 8 word list 27 9 TSM and Key Shell 26 31 typographic conventions 25 5 TZ 26 30 Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in U understanding Key Shell 27 1 undoing configuration changes 26 27 using HP UX commands 26 11 inv
22. Aliasing can provide easier typing by both abbreviating long command lines and automatic replacement of long path names Both new users and advanced users should read this chapter Setting an Alias To create an alias for POSIX Shell use this syntax alias word command a To create an alias for Korn Shell use this syntax alias tx word command Lee Any time alias is followed by a word the shell assumes you are defining a new alias or asking for the value of a defined alias The word parameter specifies the new alias s name and the command specifies any command or long command line The x option exports aliases and t tracks aliases These options are discussed in the following sections Tracking Aliases and Exporting Aliases Part Ill POSIX and Korn Shell Aliasing 18 1 FINAL TRIM SIZE 7 5 in x 9 0 in 18 For example alias who who sort redefines the original who command to the line enclosed in single quotes Now when you perform a who you get a listing of all the users on the system sorted in alphabetical order If you type alias followed by who it returns the value of the new alias For example alias who who who sort Suppose you want to use several aliased commands on one command line To do so leave a space as the last letter in the alias definition If the last letter is a blank the word following the first alias is also checked for alias substitution
23. EOF terminator is a more reliable way of achieving the same end 14 18 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in Catching Interrupts If our shell script creates temporary files we may wish to catch interruptions of the shell script so that we can clean up these files To do this start your script with onintr label where label is a program label marking the code that handles the interrupt condition If an interrupt is received by the shell C Shell will do an automatic goto label and execute the desired code If we wish to exit your program with a non zero status make exit 1 a part of your interrupt handling code An Example Shell Script This script backs up a list of C programs only if they are different from previously backed up versions The files are stored in your home directory in the subdirectory backup It makes use of the foreach statement to execute all of the commands between the foreach statement and its matching end The script might be invoked with bkupscript c bin csh foreach i argv if i c then if the file is not a c file then echo i is not a c program print an error message and continue continue with the next file else echo i is a c program endif echo check file backup i t Part Il C Shell Commands Jobs and Scripts 14 19 FINAL TRIM SIZE 7 5 in x 9 0 in 14 14 the 7 t takes the tail part of the original file n
24. FINAL TRIM SIZE 7 5 in x 9 0 in functioning of the program because the destination of output from the program is changed at the system level The program is unaware of the change I O redirection enables you to change a specific data path of a program while leaving its other data paths unchanged For example stdout can be stored in a file instead of written to your screen How to Redirect Input and Output I O redirection symbols are entered on the shell command line or from a shell program The program begins executing with the data paths specified by the redirection symbols To specify I O redirection for a program each file name is preceded by a redirection symbol as in programA lt file_name programB gt file_name Spaces between the redirection symbols and the file names are optional The symbol identifies the name that follows it as a file for input or output The redirection symbols are listed in Table 3 1 Table 3 1 Redirection Symbols Symbol Function Example lt Read standard input from an existing file program1 lt input data gt Write standard output to a file program2 gt output data gt gt Append standard output to an existing file sample prog gt gt output data Note Using gt destroys any previous contents of the file specified to receive the output If a file s contents must be preserved use gt gt Note Be careful not to use the same file for standard input a
25. POSIX and Korn Shell Command Reference 24 37 FINAL TRIM SIZE 7 5 in x 9 0 in 24 typeset Syntax For Korn Shell only typeset HLRZfilprtux n name value wee The typeset command sets the shell variable name equal to value whose type depends on the options used When invoked inside a function the value of the name is only temporary i e local until the function is exited then the original value is restored If instead of the in front of the options a is used the type is turned off If no options or specific options and no names are given the parameters with those options are displayed Example typeset i numi num2 total typeset typeset r This example defines the variables num1 num2 and total as integers Then all the attributes of all the parameters are listed followed by the r or readonly parameters See Chapter 23 for a detailed explanation of all the options 24 38 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in ulimit ulimit Syntax For Korn Shell only 24 ulimit n This command sets limit n on certain resources a spawned process uses such as time stack area files sizes etc See Chapter 23 for a detailed explanation of all the various options Example ulimit f 1000 This line limits the size of files written by the shell or a spawned process to 1000 disk blocks Part Ill POSIX and Korn Shell Command R
26. escaped Note that there s no harm done in escaping non special characters Part Bourne Shell Basic Shell Programming 5 7 FINAL TRIM SIZE 7 5 in x 9 0 in The Double Quote The double quote quotes anything enclosed in two double quotes except and grave accent For example echo diri is an old directory The dollar sign interprets dir1 as a parameter the backslash ignores the following double quote in other words it does not end the echo string but includes the double quote as part of it The Single Quote The single quote will quote everything enclosed in two single quotes except the single quote itself So the above example could be represented as echo dir1l is an old directory Notice where the single quotes begin If we place dir1 inside the single quotes the value of dir1 will not be printed rather the exact characters dir1 since the dollar sign would be ignored as a special character Note If you leave off a quote when entering commands in the shell you will receive a secondary prompt usually a gt This just means you need to type in the closing quote Command Substitution The grave accent indicates a command substitution Note Pay particular attention to the difference between the grave accent and the single quote The single quote is usually located below the double quote on the 46020A and 46021A keyboards and the grave a
27. is the number of positional parameters passed to the script To make typing easier you can use an abbreviation for test The square brackets enclosing the options and parameters do the same as the test command For example if eq O Note This is the most common usage has the same meaning as the first line in the above example if test eq 0 Note Be sure to separate the square brackets from any characters with a blank If you do not the brackets will be assumed to be part of the options Testing files is another use for test This command in addition to its many other capabilities enables you to check if a file is a directory is readable or is writable Read If you wish to receive input during the execution of a shell program you can use the read statement with the following format read parameter where parameter means a list of one or more parameters When the computer executes this statement it gets input from the keyboard unless you use redirection symbols to get input from a file Each word words are separated by blanks typed in is assigned to the respective parameter in the 5 12 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in list with the leftover words assigned to the last parameter To see how this is used see the example at the end of this chapter Exit Each command returns a status when it terminates If it is unsuccessful it retu
28. lt file gt you would type a file name a If you make a mistake use the Back space key to back up past the error and fix it You can also edit the command line with the keyboard editing keys and arrow keys For more information refer to the section titled Editing the Command Line m To see a softkey command translated into HP UX syntax before being executed use the insert line key If you do not have an Insert line key press Tab instead 26 4 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in m To execute the command directly use the Return key After you execute a command you will remain on the current key bank unless you set the KEYMORE variable refer to the section titled Setting Shell Variables a To cancel a command use the key a If you encounter errors while using Key Shell refer to the online help topic keysh errors To determine if a softkey command you have entered is complete and can be executed look for the following cues 26 1 Check that Key Shell is not displaying a prompt message that describes a required action such as Enter the name of the file 2 Optional Press Insert line to translate the command to HP UX syntax Key Shell will display a prompt and refuse to translate the command if the command is incomplete 3 Press Return to execute the command Key Shell will display a prompt and refuse to execute the command if the command
29. newfile 24 34 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in time time Syntax 24 time command_line This keyword executes the command_line and then displays the execution time of the user the system and command_line Example time ls This line lists out the files in the current directory followed by three lines real user sys showing execution times Note time is not a keyword in the POSIX Shell Part Ill POSIX and Korn Shell Command Reference 24 35 FINAL TRIM SIZE 7 5 in x 9 0 in 24 times Syntax times This command simply prints the accumulated user and system times to the nearest hundredth of a second for the shell and for processes run from the shell Example times 24 36 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in trap trap Syntax 24 trap arg signal o This command waits for signals sent to the shell and traps it Then it executes arg a command_line If signal is 0 arg is executed only once after the shell is exited After setting traps typing trap with no args lists all commands associated with signals Example trap echo Command failed ERR This sets a trap which prints Command failed on the terminal screen whenever a command run by the shell returns a non zero value See Chapter 23 for a detailed explanation of signals and traps Part Ill
30. usr keysh C 25 Italics Manual titles and emphasized words appear in italics as do values that you supply For example in the command below you would substitute the actual name of a file for file name more file name Return Words or letters in boxes refer to keys on the keyboard Mail Words in shaded boxes refer to softkeys Each softkey corresponds to a function key on your keyboard through 8 Refer to cp 1 References like this refer to entries in the HP UX Reference If you cannot find an entry in the manual where you expect it to be use the HP UX Reference index These entries can also be found online with the command man entryname For example man cp Part IV Key Shell Introducing the Key Shell 25 5 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 26 Getting Started With Key Shell This chapter explains the basics of using Key Shell All users should read this chapter More advanced users should also read Chapter 27 for information on 26 customizing Key Shell This chapter discusses the following topics m Starting Key Shell m Using Key Shell a Configuring Key Shell m Setting shell variables a Using Key Shell with Terminal Session Manager Starting Key Shell When you first log on to an HP UX system the Bourne Shell is the default shell To use the Key Shell instead first ensure that the following shell variables are set and exported in your profile file Dep
31. your home directory is substituted instead tilde can be used alone with the cd command to change to your home directory Ifa appears in the middle of a word it is not interpreted as a metacharacter and is left undisturbed The slash character also has special significance in file names Quotation separates components of a file s pathname For example bin csh is the pathname to the file csh The first slash in a pathname or a single slash aliases the system s root directory Metacharacters prevents interpretation of the character which follows it as a metacharacter For example typing ls prints a list of all files and directories and in the current directory Typing Is prints not found prevents interpretation of a string of characters as commands or metacharacters For example if you set a variable to contain a command string the command string may in turn contain metacharacters Thus whenever the variable is referenced there is a risk that the metacharacters could be inappropriately processed By enclosing the string within single quotes unwanted processing of any metacharacters in the string is avoided Part Il C Shell Aliases Substitution Metacharacters 12 7 FINAL TRIM SIZE 7 5 in x 9 0 in 12 prevents interpretation of metacharacters in a string while allowing normal command and variable expansion Double quotes are similar to single quotes except that only metacharacters ar
32. 1 FINAL TRIM SIZE 7 5 in x 9 0 in 11 All of the capabilities that you are about to see can be used without this special prompt but they are easier to manipulate if you have a prompt that provides event numbers of each event executed To see what is in your history buffer type in the command history without arguments Your display may appear as shown below 6 history 1 ls als cat junk pr memo lp mail jd lt memo vi cshre history OnP WN 7 4 Re executing Events You can re execute a previous event by referencing the event in your history buffer Events can be referenced by m event number a relative location from the current event m the text of the event As a special case the immediately previous event can be referenced by two successive exclamation points The first activates the substitution facility the second references the most recent previous command 11 2 Command History Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 11 Referencing by Event Number One way to re execute an event stored in the history buffer is to reference its event number For example 7 4 2 cat junk This is the contents of the file junk 8 re executes event number 2 Notice that the event to be re executed is echoed on the terminal before it is executed so you can verify that you are referencing the correct event Referencing by Relative Location Another way to re execute an event
33. 11 vi in line editing mode 20 2 invisible softkeys 26 10 visible softkeys 26 9 Key Shell 26 4 adding 26 16 online help 26 6 list 26 18 visible softkeys 26 9 VISUAL 16 10 16 12 20 2 20 4 ust keysh C keyshre file 26 3 usr keysh C softkeys file 26 16 26 19 Ww 27 3 wait 24 43 utilities 15 1 wait command 8 15 whence 23 6 24 44 V while 6 3 14 16 21 12 24 45 value of a parameter 16 3 19 4 whitespace 15 6 variable 5 2 9 5 who 17 1 17 3 18 1 18 3 18 8 variables accessing 14 11 whoami 17 3 variables assigning values to 27 12 word 15 6 vi 20 2 word list 27 9 Index 14 Master Index FINAL TRIM SIZE 7 5 in x 9 0 in
34. 2 3 16 1 process limits 23 17 process number 16 10 process number acquisition 14 12 process parent 2 3 17 2 profile 18 3 20 2 20 5 21 1 profile 16 4 16 6 16 14 profile customizing 4 5 profile file 4 3 26 1 26 3 26 28 program 9 4 programming language 15 3 21 1 programming shell 5 1 prompt 13 4 prompt 16 2 prompt 10 7 prompts 1 4 4 6 ps 16 11 17 2 17 3 17 10 22 1 PS1 26 26 PS1 16 3 16 9 16 12 PS1 environment variable 4 5 4 6 PS2 16 9 16 12 17 10 PS2 environment variable 4 6 5 1 PS3 16 9 16 12 21 10 Index 10 ps command 2 2 pwd 18 1 24 26 PWD 16 9 16 12 Q quitting Key Shell 26 2 quotation metacharacters 12 7 quotes back 17 9 19 11 definition 17 9 definitions 17 9 double 17 9 single 17 9 quoting 5 7 quoting metacharacters 17 9 R RANDOM 16 10 16 12 read 5 12 16 12 21 2 23 4 24 27 reading data 21 2 readonly 23 13 24 28 readonly command 8 14 recursive function 21 20 redirecting combined output 8 3 redirecting input 3 2 redirecting input output 17 10 redirecting output 3 2 redirection 3 2 3 5 4 2 8 4 9 4 redirection symbols 17 10 redirect operator 17 10 re executing events 11 2 reference entries HP UX 25 5 referencing events 11 2 regular files 9 2 rehash 14 2 rehash used to update path variables 13 4 relative location 11 3 remainder 8 7 removing aliases 18 8 removing softkeys 26 23 M
35. 3 FINAL TRIM SIZE 7 5 in x 9 0 in Here is an example of how to set a variable equal to a list of string values or a set of numeric values 22 23 6 24 1 25 mike 26 27 0 28 29 3 45 30 The variable expansion sequence returns the number of elements in the variable array The sequence returns a one 1 if the variable exists and a zero 0 if it does not set cohorts bill john mike steve mary lars echo cohorts x x echo cohorts echo cohorts 3 unset cohorts echo cohorts SS set nums 1 234 2 3 45 echo nums 3 SS The setenv Command The setenv command is used to set environment variables whose values are global to the shell and any process it creates For example setenv TERM hpterm sets the value of the environment variable TERM to hpterm See environ 7 in the HP UX Reference The source Command The source command can be used to force an update of the current shell environment by causing it to read commands from a file instead of standard input For example source cshrc 14 4 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 14 can be used after editing your cshrc file to change any variables that you modified Note that commands executed from the specified file are not placed in the history buffer only source command_file is The time Command The time command is used to determin
36. 4 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in This example shows the sub menu options for the Copy files softkey string lt files gt disable 1 enable all editrule append argument required Enter the name of the file s to copy option to disabled required Enter the name of the file s to copy then select to 27 string lt dest gt editrule append argument required Then enter the name of the file or directory to copy the file s to Part IV Key Shell Customizing the Key Shell 27 5 FINAL TRIM SIZE 7 5 in x 9 0 in 27 Softkey Attributes Softkey attributes define the behavior of softkey nodes For example attributes specify prompts and online help indicate if selecting the softkey enables or disables other softkeys and specify how the command should be translated into HP UX syntax Softkey nodes can have the following attributes as shown in Table 27 1 All attributes are optional 27 6 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 27 1 Softkey Attributes Attribute Meaning Example disable count Selecting this softkey node disables count softkey nodes to the right of this one and all the nodes to its left count can be a positive or negative integer or the word all The default is 0 The line option owner disable all in a softkey definition means that when the owner o
37. 6 5 2 shell programming 5 1 shell programming advanced 6 1 shell programming special commands 8 7 shell script 4 1 5 1 shell variables 4 3 shift 5 5 Index 4 signals 8 11 single quote 5 8 special characters 5 7 special commands shell programs 8 7 standard input 3 2 standard output 3 2 stdin 3 2 stdout 3 2 string manipulation 8 7 strings 8 8 structure 2 2 stty 4 4 stty sane 4 4 subshell 6 5 8 7 substitution command 5 8 substitution parameter 5 3 subtraction 8 7 suppressing special characters 5 7 system prompt 4 5 system structure 2 2 system times 8 15 T tabs 4 5 tee 7 1 TERM environment variable 4 4 test command 5 11 times 8 15 trap command 8 11 type command 8 13 U UID 2 3 ulimit command 8 15 unset command 8 11 until 6 3 user created parameters 5 2 user identifier 2 3 user times 8 15 Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Index Vv Ww variable 5 2 9 5 wait command 8 15 while 6 3 Part I Bourne Shell Index 5 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Part Il C Shell Preparing to Use C Shell Command History Aliases Metacharacters Shell Variables Commands Jobs and Scripts FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 10 Preparing to Use the Shell Introduction esh pronounced C Shell is an HP UX command language inte
38. 9 0 in If arg is omitted or is all trap signals are reset to their original values If signal is ERR then arg will be executed whenever a command has a non zero exit code The ERR trap is not inherited by functions If the signal is 0 or EXIT and the trap statement is executed inside the body of a function then the command arg is executed after the function completes If signal is EXIT for a trap set outside any function then the command arg is executed on exit from the shell 23 The ulimit Command for Korn Shell only This command sets limits on specified resources used by a spawned or child process subprocess The syntax is ulimit f 7 where n is the size to be set depending on the type of limit set by the option f A list of those options follow If no option is given f is assumed If n is not given the current limit is printed To see the current limit type ulimit To change the size of file the current process or a spawned process can create type ulimit f 1000 where f imposes a size limit of n blocks on files written by child processes files of any size may be read Part Ill POSIX and Korn Shell Advanced Concepts 23 17 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 24 24 Command Reference This chapter is a command reference for the POSIX and Korn Shell commands Commands are in alphabetical order explained briefly and followed by their syntax an
39. Creating and Executing Shell Scripts oaoa aaa aaa 21 1 Commenting aa a 212 Data Input and Output aaa a 21 2 Reading Input Data a u a a a a a 21 2 Printing Data ooa aaa aaa 21 4 Using echo o oaoa a aa 24 Using print 2 a aaa 21 6 Conditional Statements 2 2 21 7 Using the test Command 2 2 2 241 7 Using the if Statement 2 2 2 ee 21 8 Using the case Statement 2 2 2 21 9 Using the select Statement 4 2 2 21 10 Using the for Loop 2 2 22 2 ee 21 11 Using the while untilloops 2 2 2 2 2 a 21 12 Using the break Statement 2 21 18 Using the continue Statement 4 2 2 21 14 Arithmetic Evaluation Using let 2 2 2 2 1 21 15 Accessing Arrays 2 1 ee ee ee ee ee 21 17 Writing Functions a a a a a a ee ee 21 18 Calling Functions e ee ee ee ee a a 21 18 Returning from a Function a 22 Controlling Jobs Creating Jobs ww ee 22 1 Monitoring Jobs 2 ee 22 1 Suspending Jobs Loe ee ee ee ee 22 2 Putting Jobs in Background Foreground Soe ee ee ee 22 8 Killing Jobs e a a 225 Shells Contents 9 FINAL TRIM SIZE 7 5 in x 9 0 in 23 Advanced Concepts and Commands The ENV Variable Co Processes The whence Command The set Command The typeset Command for Korn Shell only The trap command The ulimit Command for Korn Shell only 24 Command Reference alias
40. FINAL TRIM SIZE 7 5 in x 9 0 in return return Syntax 24 return n The return command stops execution of a function and returns to the calling shell script with an exit status of n If n is not specified the returning status is that of the last command executed within the function When return is invoked outside the boundaries of a function it acts as an exit Example if grep xxx myfile gt dev null 2 gt amp 1 gt then gt else return 4 gt fi This is the same example used in the exit section The only difference in the scripts response is that it returns with the status of 4 search gt if grep xxx 1 gt dev null 2 gt amp 1 gt then return 1 gt else return 0 gt fi gt search myfile The first line defines a function called search which checks a given file for a string xxx This function inverts the normal return value of grep Therefore if the string is found the function returns 1 else if the string is not found or the file is not readable it returns 0 Part Ill POSIX and Korn Shell Command Reference 24 29 FINAL TRIM SIZE 7 5 in x 9 0 in 24 select Syntax select parameter in words do command_lines done This command prints on the screen a set of words each preceded by a number Then the PS3 prompt is printed and the line typed by the user is read into the REPLY variable If this line consists of the number of one of the listed word
41. For example pwd tmp alias hcd echo hello cd alias p users george hcd p hello pwd users george Since cd is followed by a space before the close quote it can be followed by another alias which is p in this case Now the command line hcd p prints hello and changes the directory The command line actually executed is echo hello cd users george 18 2 Aliasing Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Tracking Aliases for Korn Shell only Aliases can also be used to automatically set a command to its full path name the first time it is executed after login This reduces the execution time needed to search for a command s location in the system directory on all later calls to 18 the command This ability is called tracking The value of a tracked alias is defined the first time the alias command is executed and the shell searches for the command s path Suppose you execute the 1s command yet you never actually set an 1s alias The 1s command is automatically tracked Now list your tracked aliases type alias t ls bin l1s The 1s command shows up as a tracked alias without the need of setting it with the alias command If you want every valid alias and trackable command name tracked use the set h command interactively or in the file specified by your ENV variable Not all commands are trackable Built in commands such as cd or pwd command are not
42. HOME evaluates to the value of HOME For details on the trap command see Chapter 23 Your logout script might contain things like a clear command that clears the terminal s screen and an echoed message as in the following clear echo Have a Nice Day 16 14 Starting Stopping the Shell Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in 17 17 Shell Grammar Certain characters or combination of characters in POSIX or Korn Shell have special meanings A small class of these special characters are called metacharacters Metacharacters have meaning to the shell other than as normal characters New users should read this chapter completely experienced users need only read the Two way Pipes section for the token amp formed from two metacharacters Using Pipes Pipes are connectors that join two or more programs or commands together A pipe allows you to take the output of one program and use it as input to another program without the use of intermediate files The metacharacter for the pipe is the vertical bar For example suppose you want to list all the current users logged into the system and then alphabetically sort them and print them out The command line reads who sort Part Ill POSIX and Korn Shell Shell Grammar 17 1 FINAL TRIM SIZE 7 5 in x 9 0 in 17 In the following example a list of people logged into a system is produced by the who command That output is
43. Key Shell 26 3 introduction to Key Shell 25 1 invisible softkeys 26 10 adding 26 19 list 26 19 K KEYBEL 26 29 KEYENV 26 29 KEYESC 26 29 KEYKSH 26 29 KEYLOC 26 29 KEYPS1 26 29 keys function 26 2 KEYSH 26 26 26 29 Key Shell adding invisible softkeys 26 19 adding text to softkeys 27 19 27 20 adding visible softkeys 26 16 cancelling a command 26 14 configuring 26 15 creating custom softkeys 27 23 customizing 27 1 default environment 26 2 deleting softkeys 26 23 editing command line 26 12 editrules 27 8 27 9 edit statements 27 9 entering commands 26 4 error messages 26 5 exiting 26 2 features 25 2 global configuration options 26 24 HP UX commands 26 11 initialization 26 3 introduction 25 1 invisible softkeys 26 10 26 19 labels for softkeys 26 15 moving softkeys 26 23 names for softkeys 26 15 Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in online help 25 3 26 6 27 21 restarting 26 27 saving configuration changes 26 27 setting shell variables 26 28 shell variables 26 1 26 28 softkey attributes 27 6 softkey definition 27 3 softkey format 27 4 softkey menu 26 2 softkey menus 25 3 softkey navigation 27 3 softkey node hierarchy 27 2 starting 26 1 status line 25 3 26 2 26 26 Terminal Session Manager and 26 31 translating a softkey command 27 8 understanding 27 1 undoing configuration changes 26 27 using 26 4 visible softkeys 26 9 2
44. a break display a single blank line and then begin a new paragraph with no indentation ip tag indent Force a break and display a single blank line Then begin a new paragraph with the specified tag and indentation For example ip 5 il tag indent Force a break then immediately begin a new paragraph with the specified tag and indentation No blank line is displayed For example il 2 ti indent Indent just the next line by the specified number of characters For example ti 3 in indent Indent all following text by the specified number of characters To stop indenting repeat the macro with a negative value for example in 5 nf Begin no fill mode Display text as is preserving new lines and spacing until an fi is encountered fi Resume fill mode after using an nf Display text with words filled to 90 of the screen width Fill is the default mode Note that the formatting commands can appear anywhere in the text and can be upper or lower case Part IV Key Shell Customizing the Key Shell 27 21 FINAL TRIM SIZE 7 5 in x 9 0 in 27 Following are two examples of help text The first example shows the help text with formatting commands as it appears in the softkey definition file help You can use the Copy_files command to copy a file to a new or existing file or to an existing directory ip 5 If you copy a file to an existing file the existing file is ov
45. are familiar with a programming language such as C Pascal or BASIC you should have no difficulty understanding the concepts in this tutorial If you have never programmed before you may wish to read about concepts such as loops which are used to repeat a specific sequence of commands more than once condition statements which are used to select based on existing values in the shell environment which command s to execute and variables which are used to store alphanumeric values that may be used in more than one place and or that may change over time Computer literacy books and beginning programming books discuss these concepts Part I Bourne Shell The Bourne Shell 2 1 FINAL TRIM SIZE 7 5 in x 9 0 in UNIX System Structure HP UX is a fully compatible enhanced version of UNIX System V The structure of the system consists of several parts which work together to bring you the HP UX operating system The kernel is the core of the HP UX operating system It controls the computer s resources and allots time to different users and tasks The kernel keeps track of the programs being run and is in charge of starting each user on the system However the kernel does not interact with the user to interpret the commands The shell is a program that the kernel runs for each user which sets up commands for execution By having several shells and one kernel HP UX is able to support many users at the same time the user s requests
46. are not actually processed at the same time but the kernel schedules processing time in a way which simulates concurrent processing By having the kernel in control it is also possible for one user to run several shells The kernel remains in control of all shells and programs When you log on to the system the kernel checks if your login identifier and password are correct It then runs a shell program for you to interact with it you never see this only the shell after successful login Most systems will start the POSIX Shell bin posix sh as a default but it is possible to run the Bourne Shell bin sh the C Shell bin csh or the Korn Shell bin ksh instead To give you an idea of processes and how the kernel schedules them let s look at the ps command which lists the processes the kernel is currently coordinating Type ps ef and receive a list similar to the following UID PID PPID C STIME TTY TIME COMMAND davek 28125 28124 0 08 50 56 12 0 02 ps ef davek 28124 28091 0 08 50 55 12 0 00 sh c ps ef gt temp davek 28091 22022 0 08 23 17 12 0 51 vi programming root 27781 1 0 06 47 58 co 0 01 etc getty console H 0 root 27097 1 0 23 51 47 05 0 03 etc getty tty05 H O root 27092 1 0 23 50 37 04 0 02 etc getty tty04 H O root 25740 1 O 11 59 58 03 0 01 etc getty tty03 H 0 2 2 The Bourne Shell Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in root 24970 1 O0 Aug 3 0 01 etc getty tty99 3 240 root 22026
47. command not just those that precede the command name n Read commands but do not execute them t Exit after reading and executing one command u Treat unset variables as an error when substituting v Print shell input lines as they are read x Print commands and their arguments as they are executed Do not change any of the flags These options can also be used with the sh command 8 10 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Unset This command will remove the specified variable or function The format is unset name where name is a list of variables or functions except PATH PS1 PS2 MAILCHECK IFS Trap The trap command waits until signals are sent to the shell program and traps them Instead of performing the default action you can have the signals processed any way you wish In other words you use the trap command to wait for certain signals from the shell which may be an unsuccessful command execution When the trap sees a signal it executes a list of predefined commands you generate The syntax is trap command_ list n where n is the signal or signals trap looks for and when they are found command_list is executed If n is 0 then the command list is executed when the shell is exited If you type trap with no arguments a list of commands associated with each signal number is printed An attempt to trap signal 11 memory fault
48. command line but rather just the root directory and decide to kill the job To kill the process use the job s number 1 and type kill 41 The kill command kills the job and the metacharacter specifies the job number 1 As shown above you are returned to the prompt Recall that 4 and 4 perform the same function as 41 since it is the current job If it was the previous job use 4 To see the status of the job type jobs 1 Terminated lsf sort gt filenames amp The line following jobs shows that the current 1sf job has been terminated If you log off the system while any of your processes are running whether in background or foreground the jobs are destroyed unless you use the nohup command see nohup 1 entry in the HP UX Reference for details Part Ill POSIX and Korn Shell Controlling Jobs 22 5 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 23 Advanced Concepts and Commands This chapter explains advanced topics and commands you will need for understanding the more difficult aspects of the Korn Shell The ENV Variable In Chapter 16 the ENV variable was discussed The ENV variable specifies a file usually kshrc which is executed when ever you spawn a new interactive POSIX or Korn Shell An interactive shell is a shell that has input and output tied directly to the terminal Therefore you can access standard in standard out and standard error To deter
49. double quotes are necessary let x x 1 6 3 1 let x x 1 6 3 1 This next script reads a value from the user compares it to 14 and prints an appropriate string based on the comparison read x y 14 if x gt y then echo greater or equal else echo less than fi Using around the expression replaces using the let let x gt y which must be quoted to allow blanks and prevent the gt from being interpreted as an I O redirection Also you do not need to put in front of x or y In this situation the let command is used as a condition 21 16 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Accessing Arrays Arrays are a collection of contiguous elements that can be accessed by a subscript Declaration of arrays in POSIX and Korn Shell is very similar to that of the C Shell An array s syntax is 21 array Lsubscript value The first line sets the element of the named array at the designated subscript to the value Unlike C Shell POSIX and Korn Shell start placement of values at the 0 element In this example testa lO first testa i second echo testa 1 second echo testa first second the array testa first two elements 0 and 1 are set to first and second The following echos display the value of the 1 element and then the value of every array element as designated by the See Parameter Sub
50. echo Hello name The first line prints a prompt and leaves the cursor one blank to the right of the The next line reads in text from the user and saves it in name Last a line is printed which includes the value of name since the string is in double not single quotes read fieldi field2 junk This reads the first whitespace separated word from an input line into field1 the second into field2 and the rest into junk which is presumably ignored Part Ill POSIX and Korn Shell Command Reference 24 27 FINAL TRIM SIZE 7 5 in x 9 0 in 24 readonly Syntax For POSIX Shell only readonly name word Lee readonly p For Korn Shell only readonly name wee This command marks the parameter names as readonly such that they cannot be assigned values The shell issues an error if you try to overwrite a names value A subshell does not inherit a variable s readonly setting If you give no names all the readonly parameters are listed Example who who am i readonly who This example sets who to the output of the command_line who am i and then marks who so it can t be changed Note The POSIX Shell provides the p option with the readonly command The p option lists all the readonly parameters and formats the output so it is suitable for re input to the shell as commands that achieve the same attribute setting results 24 28 Command Reference Part Ill POSIX and Korn Shell
51. effective even after the loop completes Traps defined in functions are local to the function Errors in functions abort the functions but not the script New shell variables such as REPLY PPID EDITOR and OLDPWD Extended vi and emacs in line editing commands Increased capabilities for parameter substitution Job Control Co processors Only in Korn Shell 15 4 Introducing the Shells Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Differences between POSIX Shell and Korn Shell Most of the POSIX Shell constructs are similar to those of the Korn Shell The differences and the new features are highlighted wherever applicable Some of the basic differences between the POSIX and Korn Shells are as follows 15 m POSIX Shell does the function lookup before the built in commands Korn Shell does the built in command search before the function lookup m POSIX Shell has a new built in utility called command that executes commands without doing the function lookup m time keyword is removed from the POSIX Shell so as to use the POSIX compliant bin time utility mw readonly and export built in commands print the variables such that the output is suitable for re input to the shell as commands m unalias has an option to remove all the alias definitions from the environment Part Ill POSIX and Korn Shell Introducing the Shells 15 5 FINAL TRIM SIZE 7 5 in x 9 0 in 15 Definition of Terms In lear
52. etc passwd file to bin ksh Once you have changed shells invoke the ksh shell by logging out and then back in From now on whenever you login ksh is your shell To make the POSIX Shell your permanent or default login shell type chsh login_name bin posix sh Setting Environment and Shell Variables Environment variables and shell variables parameters are set in the profile and ENV files The ENV file is often but not always kshrc These variables create part of the environment in which you work such as your prompt string PS1 Environment variables are shell parameters that are global and used by your shell to create a special environment for subshells and any commands you may invoke This environment is active until you logoff These global or exported environment variables can be seen and used by subshells and other subprocesses Shell variables are shell parameters that are local to your login shell and not passed on to any subprocesses or subshells 16 4 Starting Stopping the Shell Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Setting Up profile and kshrc When the POSIX or Korn Shell is your login shell it looks for these following files and executes them if they exist etc profile This default system file is executed by the shell 16 program and sets up default environment variables profile If this file exists in your home directory it is executed next at login At any t
53. file A file containing commands each on a separate line When the entire file is executed the commands are executed in the order in which they appear in the file sequential In order not at the same time shell A program that interfaces between the user and the operating system HP supported shells are bin sh bin ksh bin csh bin rksh bin rsh bin posix sh variable See Parameter vi The vi editor visualize Part Bourne Shell Bourne Glossary 9 5 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Index Index Special characters 5 13 5 2 5 3 amp amp 8 1 3 6 6 5 lt 3 3 3 5 gt 3 3 3 5 gt gt 3 3 3 5 3 6 5 7 A accumulated user and system times 8 15 addition 8 7 advanced shell programming 6 1 arithmetic operations 8 7 asking questions 5 10 automatic scripts 4 3 background command process number 8 17 background processes 7 2 9 1 background processing 3 2 backslash 5 7 banner 5 9 beep 6 8 block special files 9 2 Bourne Shell 2 1 commands 3 1 Part I Bourne Shell FINAL TRIM SIZE break 7 2 break from a loop 6 8 Cc c 4 2 4 3 5 7 C 2 3 cancel special character meaning 5 7 case 6 4 6 9 CDPATH environment variable 4 6 changing group identification 8 14 changing permissions 4 1 character special files 9 2 chmod command 4 1 combining shell commands 3 1 COMMAND 2 3 co
54. from all of the commands is placed in a file called contents Note Please be aware that redirecting output from causes a subshell to execute Hence any shell variables set created or changed from within the won t be effective outside of it This is not true if output is not redirected Defining Functions The more complicated your shell programs get the more you will want to modularize them by using functions This way you can create generic functions which can be re used and eliminate repetitive code To define a function use the following syntax name list where name is the name of the function and lst is a list of commands used in the function Part I Bourne Shell Detailed Reference 8 3 FINAL TRIM SIZE 7 5 in x 9 0 in Here is an example to show how functions are defined stat if d 1 then echo 1 is a directory return 0 else echo 1 is not a directory return 1 fi This function tests the filename to see if it is a directory If it is it returns a status of O see Return Values later in this chapter Otherwise it returns status 1 Do not forget to place the semi colon at the end of the last line You can type your function in its entirety at the beginning of the shell program When you wish to access it you use the following format name parameter ee where name is the name of the function and Lparameter refers to any optional positional parameters you
55. from that file are automatically loaded for use as invisible softkey commands 5 To place the softkey in the default position after all the other softkeys press Return Otherwise select and place select where the softkey should be placed in the menu and press Return If you select and place before softkey you will be prompted to type the name or label of the existing softkey before which you want the new softkey to be placed 26 16 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Following are some examples that illustrate adding visible softkeys m To add the od softkey to the end of the top level softkey menu and label it Octal dump use this command Keysh config softkey add od with label Octal_dump Retum m To add the paste softkey to the beginning of the top level softkey menu use this command The softkey will be labelled Paste by default Keysh config softkey add paste and place as first softkey Retum 26 a To add the custom emacs softkey from the file users rpt softkeys to the top level softkey menu immediately before the 1s softkey use this command Keysh config softkey add emacs from user rpt and place before softkey 1s Return m To change the definition of the Mail softkey so that it calls the elm mailer instead of the mailx mailer use the following command Keysh config softkey add elm with label Mail and place as first softkey Return Part IV Key Shel
56. is incomplete Note that you can press Return or Insert line regardless of the cursor s position on the command line Part IV Key Shell Getting Started With Key Shell 26 5 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Using Online Help Online help is available for all pre configured softkeys listed in Table 26 3 and Table 26 4 and their options In addition the following help topics are available using help How to use the online help using keysh How to use Key Shell editing Editing the command line visibles Visible softkeys invisibles Invisible softkeys keysh errors Key Shell error messages regexp_patterns Regular expressions and pattern matching redirect_pipe Command input output redirection and piping More at the bottom of a help message indicates that the help is more than one screen long To continue reading press the space bar To exit a help screen press q 26 6 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 26 1 explains the methods for accessing help Table 26 1 Using the Online Help To get help on Do this A general topic Select Help Help topics then select a topic softkey A visible softkey command or Select Help then select the softkey for which softkey option before you have you want help selected the softkey 26 A visible softkey command or Select Help then press Return softkey o
57. line are continuations of the PATH parameter To add to the path you set the variable PATH to its previous value PATH followed by a colon then continue listing the directories As you learn more about shell programming and develop several programs you may wish to call these programs from any directory One way to do this is to create a library a directory which contains all of these shell programs Then place the path to the library into the PATH variable This directory will always be searched when you type the program name MAIL sets the file in which to look for new mail TERM sets the terminal type This example is using an HP 2623 Graphics computer terminal The export command marks parameters for exporting their values to the environment The export command can be thought of as a way of letting other commands know the value of a variable If you do not export a parameter other processes will not know its value The stty command sets characteristics for your terminal Setting the kill characteristic to c control c tells the computer to interrupt the current process when control c is pressed 4 4 Shell Scripts Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in stty sane resets all modes to some predefined reasonable values tabs will set the tabs to the default format for your terminal The T option is followed by the terminal type here it is TERM which is a parameter we set earlier to 2623 The last
58. line displayed in the screen above although complicated causes the kshrc to not be executed unless you are in an interactive shell and therefore quickly spawns a new shell For a complete explanation of this command line the START command line and interactive shells see Chapter 23 m TERM sets the terminal type for which output should be prepared You should set this to the terminal type you are on m The export command puts the values of these parameters in the environment makes them global so that subprocesses have access to them m The stty command sets terminal characteristics to the default i e sane values You should also set susp to Z that s CTRL_ Z_ so you can get job control This is an example of just one profile When you create your own profile using an editor you can set many different shell variables depending on how you want the environment set up See Table 16 1 Shell Parameters later in this chapter for a listing of possible variables Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 7 FINAL TRIM SIZE 7 5 in x 9 0 in 16 Setting up ENV This shell script sets values such as path names and aliases These values can then be accessed by shell subprocesses A ENV file may look like lg abbreviation of long path name alias who who sort set o monitor trap HOME logout 0 The first line of the example ENV file sets an abbreviation for a long
59. name Disabled Your user name host name Enabled Your host name current dir Enabled The current directory mail status Enabled The mail status You have mail No mail or You have new mail date Disabled The date time Enabled The time of day In addition you can use the KEYSH shell variable to add any arbitrary text to the status line This text is always displayed first You can include the same type of information in KEYSH that you normally would in the PS1 variable For more information refer to the section titled Setting Shell Variables 26 26 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Saving Configuration Changes If you want to manually write the configuration changes you have made to your keyshrc file select Keysh config write Note that keysh automatically writes configuration changes as you make them For example if you have configured keysh differently in two windows and you do not want to keep one of the configurations go to the window with the configuration you want and select Keysh config write to write that configuration to keyshrce Then go to the other window and restart keysh 26 Restarting Key Shell After changing keysh s configuration in one window you can update the configuration of any other windows by selecting Keysh config restart in those windows If you want keysh to restart from the orig
60. name is a pattern which the shell should replace with all file names in the specified or current if not specified directory that match it Characters that identify abbreviations cause C Shell to expand the file name based on the abbreviation provided Metacharacters that represent patterns include expansion character matching any single character when specifying a filename For example to collect the files filea o fileb o and filec o in the file named total o type in cat file o gt total o expansion character matching any sequence of characters including the empty sequence To remove all files beginning with the word old type in rm old O expansion matching of any single character or range of characters separated with a dash listed within the brackets For example to list all the files with the same root name file followed by any single lower case character type ls file a z This could produce fileo filep 12 6 Aliases Substitution Metacharacters Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in Metacharacters that identify abbreviations include 12 abbreviating a set of words which have common parts For example the files list last and lost can be listed with ls lfaio st substitutes that path name of the specified user s home directory Syntax is a tilde followed by the login name of the desired user If the tilde is followed immediately by a slash and a file or path name
61. not connected with pipes can be changed If you specify a change to a data path being used with a pipe then an error occurs The following changes are permitted m The standard input of the first program using a pipe can be redirected with the lt symbol m The standard output of the last program using a pipe can be redirected by using the gt symbol or appended to an existing file with the gt gt symbol Examples The following commands show how programs can be connected with pipes and how additional changes can be made to data paths with redirection symbols Part I Bourne Shell Shell Commands 3 5 FINAL TRIM SIZE 7 5 in x 9 0 in The first example takes the standard output from test_prog1 and uses it as standard input to usr output_prog test_progi usr output_prog The next example runs four programs connected with pipes and puts the output of the fourth program in store_file get_it check_it process_it format_it gt store_file Pipe Example The following pipe uses several of the symbols we just discussed Try to figure out what will happen before you read the description below sort pdir pr pdir lpr amp sort local amp cat local gt gt pdir This pipeline will run three sets of commands sequentially The first command is to sort the pdir file When it is completed the second command set is executed The parentheses separate the commands so the shell knows which command to associate with a symbo
62. or C type just Q to step through After using Esc or Esc C and k or to step back use or to step forward Esc count G Recalls earlier command number count Note that this is upper case G 20 10 Command lines and Command History Part Ili POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in So if the set of commands looked like fc 1 20 21 more file 22 ps 23 pwd 24 lsf and you pressed ESC k the shell displays s W pwd Note that the Esc seems to have no effect and the k does not appear on the display For every k typed after that the shell displays one line further back in the history file but at the same prompt That is only one line at time appears at the current prompt If you go too far backwards in the history file move forward again using the Q For example p O pwd Note that the ps is replaced by the pwd If you use j or k to move from a command line you are editing to another all the changes are lost To specify a certain line number use Esc count G as follows s 06 ll a Once you find the command line you are searching for you can re execute it by pressing Return or edit it using the vi in line edit commands and then re execute it Part Ili POSIX and Korn Shell Command lines and Command History 20 11 FINAL TRIM SIZE 7 5 in x 9 0 in 20 Accessing the History File From emacs Mode There are other CTRL sequence
63. or command line which references an alias before the alias has been executed on it the script or command will not run The real concern is that you define and use an alias on the same line such as in unalias x just to make sure alias x echo XXX x ksh88 x not found At the time x was parsed the alias was not yet defined But if you continue the example x XXX This time the alias worked because it is now defined Part Ill POSIX and Korn Shell Aliasing 18 7 FINAL TRIM SIZE 7 5 in x 9 0 in 18 Unsetting an Alias There will be times that you set a common command such as who with a new definition and then decide you need its old functionality back You can quote or protect the alias name to temporarily override the alias for example who Or you can permanently regain the old functionality by unsetting the alias To unset an alias use the unalias command In one of the previous examples who was set to who sort To unset who type unalias who Then type alias and notice from the listing that who has disappeared from the alias list and now performs it original function The results of running who before and then after should look something like this who mary tty02 michael tty04 nick tty01 unalias who who nick tty01 mary tty02 michael tty04 The POSIX and Korn Shells default aliases i e false integer can be unset or redefined as well The POSIX Shell also provides
64. positional parameter the user typed after the shell program name and the dir1 parameter the directory the user typed when prompted 4 test if itis a file If x was instead f the user is prompted to enter the new filename 5 response is not d or f If the user typed in neither d or f then an error message is printed In all of the above three cases the exit command is used to terminate the shell program Pay attention to how positional parameters are used and how you match up if s else s elif s and fi s 5 16 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Advanced Programming The example at the end of this chapter will be a script created with the information you will have learned The example is similar to an HP UX command Looping Many times sequential processing in a program is just not enough We need a mechanism which will allow us to repeat the same set of commands using a different set of parameter values To accomplish this in shell programming you can choose between three looping constructs for while and until For The for construct allows you to execute a set of commands once for every new value assigned to a parameter Look at the following format for parameter in wordlist do command list done where parameter is any parameter name wordlist is a set of one or more values to be assigned to parameter and command list is a set o
65. produces an error Table 8 2 is a list of the signal numbers their descriptions and whether they can be trapped To trap for signals 0 1 2 3 15 and execute a certain set of commands you would use a command similar to trap echo removing temp file rm temp O 1 2 3 15 Signals 1 2 and 3 cannot be trapped if the script is run in the background using nonsequential processing symbol amp Signal 9 should not be used as an argument to trap because it can never be caught as well as signal 14 it is used internally by sh 1 Part I Bourne Shell Detailed Reference 8 11 FINAL TRIM SIZE 7 5 in x 9 0 in Table 8 2 Signals Signal Description Trap Characteristic 00 Success Trappable 01 hangup Trappable unless in background 02 interrupt Trappable unless in background 03 quit Trappable unless in background 04 illegal instruction Trappable 05 trace trap Trappable 06 software generated sent by Trappable abort 3C 07 software generated Trappable 08 floating point exception Trappable 09 kill Cannot be trapped 10 bus error Trappable 11 segmentation fault Cannot be used as argument to trap 12 bad argument to system call Trappable 13 write on a pipe with no one to read it Trappable 14 alarm clock Cannot be trapped 15 software termination signal Trappable 16 user defined signal Trappable 17 user defined signal Trappable 18 death of a child process Cannot be used as arg
66. prompt Making C Shell Your Login Shell To make C Shell your default login shell type in chsh login_name bin csh The argument login_name is your login name The command chsh means change shell When you change shells the new shell is your default login shell until you use chsh again chsh changes your login shell not your current working shell To change to the new login shell exit from your current shell then log in again C Shell is stored in bin csh The Bourne Shell is stored in bin sh To make the Bourne Shell your login shell type chsh login_name If no shell pathname is specified on the chsh command line the login shell is set to default Bourne Part Il C Shell Preparing to Use the Shell 10 3 FINAL TRIM SIZE 7 5 in x 9 0 in 10 Terminating C Shell Various ways can be used to terminate C Shell depending on the current value of the boolean flag ignoreeof To determine the current value of ignoreeof type set without arguments This lists all currently defined variables and their values Boolean variables are listed only if set For example 25 set argv O autologout 15 cwd users login_name history 15 home users login_name ignoreeof ignoreeof is set for this erample noclobber prompt shell bin csh status 0 term hp2622 path bin posix bin usr bin usr local bin etc users login_name 26 _ exit or logout if in a login shell can be used to exit C Shell at any ti
67. s commands output The data that results from a program or computer process parameter The second and subsequent words data after a command or program Parameters are used to pass information to a program or command Part Bourne Shell Bourne Glossary 9 3 FINAL TRIM SIZE 7 5 in x 9 0 in parse Separating statements into basic units for translating into machine language or for interpreting path An ordered sequence of steps from origin to destination path name A series of directory names separated by characters and ending in a directory name or a file name permission Operation allowed to a specified type of user pipe The name given to a command line where the output of one command becomes the input to another command The commands must be connected by a character process A process is the environment in which a program or command executes It includes the program s code data status of open files and value of variables For example whenever you execute a shell command you are creating a process whenever you log in you create a process program A sequence of instructions performing a task redirection Changing the default path of input or output sending output to a file instead of to the screen for example screen The device with which the user sees computer output the CRT or terminal 9 4 Bourne Glossary Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in script
68. six lines construct a condition we will learn the details of conditions later These lines check if you have received any mail If you have the message You have mail will appear on the screen Customizing profile If you wish to customize your profile script you can add any of the items discussed in the shell programming sections The following are some system parameters and commands you can add to your profile script which may be of interest PS1 is a system parameter which sets the value of the system prompt The default is but you can change that to anything by using the following format PS1 string where string is any character string To have the script clear the screen include a line with the clear command on it To have anything printed on the screen include a line with the echo command echo string where string is what you want to appear on the screen Part Bourne Shell Shell Scripts 4 5 FINAL TRIM SIZE 7 5 in x 9 0 in Here is a list of some system parameters Table 4 1 Shell Parameters Parameter Description HOME The default directory for the cd command PATH The search path for commands CDPATH The search path for the cd command MAIL If this parameter is set to the name of a mail file and the MAILPATH parameter is not set the shell tells you when mail arrives MAILCHECK This parameter tells how often in seconds the shell will check for mail The default is 600 s
69. special inside single quotes The backslash forces 1s to list the file actually named prog not all files starting with prog The single quote gt protects everything enclosed between two single quote marks except the single quote itself That is only the single quote can t be protected all other metacharacters have no special meaning inside single quotes The double quotes allow parameter and command substitution The inside double quotes quotes the characters and rather than the shell evaluating them This example echos the path name contained in the variable PWD When the is placed in front of the the echo cannot evaluate PWD Part Ill POSIX and Korn Shell Shell Grammar 17 9 FINAL TRIM SIZE 7 5 in x 9 0 in 17 Input and Output Standard input stdin is the default place from which a program reads its input the default stdin is the keyboard Note that a command can read input from anywhere it chooses not just stdin Standard output stdout is the default place to which a program writes its output the default is the terminal display Standard error stderr is the default place where the system writes error messages the default is the terminal display When a command is executed its stdin stdout and stderrcan be redirected using special redirection symbols When you redirect input or output using redirection symbols you place it somewhere other then the default area
70. sub menu softkeys are options or strings attributes Optional Attributes define the behavior of the softkey and how the softkey is interpreted editrules Optional Editrules are part of the softkey attributes and define how the softkey is translated into HP UX syntax Part IV Key Shell Customizing the Key Shell 27 3 FINAL TRIM SIZE 7 5 in x 9 0 in 27 The basic top level softkey node definition has the following format softkey name attributes editrules This example shows the top level softkey definition for Copy files softkey Copy_files command editrule append cp If a softkey has associated sub menus the trailing is replaced with a list of child softkey nodes enclosed in curly braces and These sub menus correspond to the lower levels of the hierarchy type name attributes editrules Child nodes can be of two types option Options appear on softkey labels and insert literal text into the command line when selected Examples include the Print files command and the double spaced option string Strings or parameters appear on softkey labels but do not insert text into the command line when selected Instead they display a hint message in the status line The hint message prompts you to type your own text into the command line Examples of string softkeys include lt files gt and lt user gt Note that the name of a string softkey must be enclosed in angle brackets 27
71. the change directory command cd type in 42 unalias cd Part Il C Shell Aliases Substitution Metacharacters 12 3 FINAL TRIM SIZE 7 5 in x 9 0 in 12 42 alias h history print pr lp W who echo You are who am i dir ls als Command Substitution A command enclosed in single back quote also called a grave accent characters is replaced just before filenames are expanded by the output from that command Thus it is possible to 43 set pwd pwd to save the current directory in the variable pwd You can now print the value of the pwd variable with 44 echo pwd users joe documents 45 Command substitution also provides a way of generating arguments for other commands For example ex grep 1 TRACE c runs the editor ex supplying as arguments those files whose names end in c and contain lines which contain the string TRACE 12 4 Aliases Substitution Metacharacters Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in Metacharacters in C Shell C Shell recognizes a number of characters as having special meaning Because they have syntactic and semantic meaning to C Shell these special characters are called metacharacters Metacharacters affect C Shell operation only as the characters are read into the shell C Shell displays an amp as a prompt when reading Metacharacters normally recognized by C Shell are ignored by C shell when runni
72. the concepts we just discussed You should try the example yourself and then try writing one yourself to get you started on your own try writing a shell program that will do the same thing the cp copy command does except have it prompt the user for input The name of the example script is move Remember to leave the first line blank or precede any comments with a blank space or tab 5 14 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in FEE AE FE FE HE HE HE TE HE HE E HE FE FE E HE FE FE FE RSH RRR HE FE FE FE HE FE FE FE HE E HE FE RRS FE FE RHEE EHH HE HE HE HE HE HE HE HE HE HE HE This shell program will prompt the user for moving files FEE AE FE FE HE HE HE TE HE HE E HE FE FE E HE FE FE FE HE E TE FE HE E HE FE FE FE HE FE FE FE HE E HE FE HE E HE FE FE FE HE HE FE FE HE HE HE HE HE HE HE HE HE HE HE HE HE 1 test if there are any arguments if eq 0 then echo No arguments include file name exit fi 2 ask if file is to be moved to directory or file echo Move to directory or new file name d or f c read x 3 test if x is a directory if not leave script if x d then echo Enter directory name gt c read dirl perform the move mv 1 dir1 echo 1 moved to diri exit 4 test if it is a file elif x f then echo Enter new file name gt c read file2 perform the move mv 1 file2 echo 1 now named file2 exit 5 res
73. the search path If you wish to see if a command is in a hash table you can use the type command Type The type command will tell you where a command is located in the directory structure It will also indicate if the command is hashed see hash above The format is type name where name is a list of commands Part I Bourne Shell Detailed Reference 8 13 FINAL TRIM SIZE 7 5 in x 9 0 in Readonly The readonly command is used to set the value of a parameter permanently The format is as follows readonly name where name is a list of parameters When you use the readonly command on a parameter it places the parameter into a set of parameters which are marked so they cannot be changed No attempts to change the value of the parameter are allowed For example let s say we specify these parameters to be readonly dogs rover knuckles chuckles readonly dogs knuckles If we attempt to change the value of say dogs dogs spot we get the message dogs is read only and the value remains at rover If you type in readonly with no parameters the default you get a list of all parameters which are readonly readonly dogs knuckles Newgrp You can change your group identification with newgrp You remain logged in but access permissions to files are done according to the new group environment With newgrp you are always given a new shell even if the command terminates unsuccessfully The fo
74. this instance the change occurs as 1 2 and 3 so the file name expands to just data_structure_ Now type in 1 2 or 3 to complete the file name For example 1s data Esc Esc expands to 1s data_structure_ If at this point you want to see all the possible expansions type 1s data_structure_ ESCc where ESC G lists three lines Part Ill POSIX and Korn Shell Shell Grammar 17 5 FINAL TRIM SIZE 7 5 in x 9 0 in 17 1 data_structure_1 2 data_structure_2 3 data_structure_3 ls data_structure This leaves you at the end of the line so you can complete the file name To do so type a and the appropriate letter or letters in the above example to complete the file name followed by a Return ls data_structure_ aa Retum data_structure_1 This special mode for adding text to a command line is explained in Chapter 20 Another expansion character is The asterisk expands the current word to the entire list of file names that match For example 1s data Esc expands to 1s data_structure_1 data_structure_2 data_structure_3 Another expansion feature allows you to interactively change your shell parameters such as PATH For example PATH PATH ESC ESC expands to PATH bin posix usr bin usr lib bin users mary bin You can now edit and change the value of your PATH variable using the techniques described in Chapter 20 17 6 Shell Grammar Part Ill POSIX
75. to be the user input for the softkey c in the preceding example Syntactically an editrule is a list of edit statements enclosed in curly braces and Edit statements can be any of the following m An expression followed by a semicolon 3 a An append statement a A dash statement m An if statement These four types of edit statements are explained in the following sections Part IV Key Shell Customizing the Key Shell 27 9 FINAL TRIM SIZE 7 5 in x 9 0 in 27 Expressions Table 27 2 shows the simple expressions you can use in keysh Key Shell stores all expressions as strings The expressions then take on string or numeric values as appropriate Simple expressions can be combined to form more complex expressions as shown in Table 27 3 Note that keysh expression combinations are like those in C with the following two exceptions m C does not have a multiple character substring a The binary and symbol in C amp is the concatenation symbol for keysh Simple expressions can also be assigned values as shown in Table 27 4 Again value assignment is the same as in C Table 27 2 Simple Expressions Expression Meaning Example variable A single letter from a to z x number An unsigned integer 31 string Any literal text enclosed in double quotes egrep char Any literal character enclosed in double quotes y word inder Indicates the word located at tha
76. uses It is mainly used to set the value of a parameter Let s begin with using set without arguments If you type set you get a list of all the parameters the system knows These will include system parameters set by your profile file and any parameters you define You can define or set positional parameters easily with set Simply follow the set command with the values for the positional parameters 1 2 and so on Here is an example set camp town ladies Now 1 has the value camp 2 has the value town and 3 has the value ladies You can also use command substitution with the set command set date Part I Bourne Shell Detailed Reference 8 9 FINAL TRIM SIZE 7 5 in x 9 0 in where 1 Thu 2 Jun and so on for a date output of Thu Jun 26 09 34 01 MDT 1986 There are several options you can use with set Preceding the option with will turn the flag on Preceding the option with will turn the flag off The format is as follows set aefhkntuve arg where the options are shown in the following table Table 8 1 Options to the set Command Option Description a Mark variables which are modified or created for export e Exit immediately if a command exists with a non zero exit status f Disable the file name generation h Locate and remember function commands as functions are defined k All keyword arguments are placed in the environment for a
77. using the syntax name value For example x 1 sets the name to x with a value of 1 Attributes of a parameter may be set with the typeset command The typeset command has many options or attributes such as readonly integer left justify it can assign to each name See Chapter 23 for details on these Setting and Using Positional Parameters Positional parameters are passed to a command or shell script or set with the set command The positional parameters follow the script or command name on the command line Then every item on the line following the command or script name separated by a whitespace is given a positional parameter name 0 1 2 3 and so forth These correspond directly to the items on the command line 0 is the first item script name 1 is the second item This assignment process continues for the rest of the parameters on the line For example the following function uses the while construct to shift through and print the parameters and their position on the command line The shift command might also help you accomplish this task see shift in Chapter 24 Part Ill POSIX and Korn Shell Substitution Capabilities 19 5 FINAL TRIM SIZE 7 5 in x 9 0 in 19 function print_args typeset i x 0 set x 0 declare x integer while x le le is less than or equal do echo positional parameter x is eval echo x let x x 1 done print_args AB C positional parameter is print_arg po
78. variables you can directly affect the shell behavior The following variables are supported by C Shell on HP UX argv This variable contains the command line arguments from the calling shell autologout This variable is used to automatically log you off the system if you do not use the system for a specified amount of time For example set autologout 60 will automatically log you off the system if you do not use the system for an hour 60 minutes To disable autologout set it to zero 0 time For example set autologout 0 or unset autologout Part Il C Shell Shell Variables 13 1 FINAL TRIM SIZE 7 5 in x 9 0 in 13 cwd The cwd variable contains the path name to your current working directory This variable is automatically changed with each cd Change Directory command At log on the default for this variable is the directory in the system variable HOME home The home variable contains the path name to your home directory The default value for this variable is specified in the system file etc passwd See passwd 5 Boolean ignoreeof The boolean variable ignoreeof determines whether CTRL D is allowed to log you off the system If set set ignoreeof logout must be used to terminate a session If ignoreeof is unset unset ignoreeof you can also use CTRL D to log off The default is set cdpath Use this variable to specify alternate directories to be searched by the system
79. you navigate through the hierarchy of softkey nodes At any one time the softkey menu displays only the nodes that you can select These are the enabled nodes disabled nodes are not displayed When you select a node other nodes on the same level may be enabled or disabled as appropriate keysh initially displays a top level softkey menu When you select a softkey with a sub menu keysh displays the appropriate softkeys for the sub menu When you have finished selecting sub menu options keysh re displays any 27 remaining softkeys in the parent menu For example the Keysh config options in Figure 27 1 are mutually exclusive Selecting the status line node disables all other nodes at the same level so that they are not subsequently re displayed A node is displayed and can be selected if either of the following is true m The node was enabled by default and was not subsequently disabled by the selection of another node m The node was disabled by default was not subsequently disabled by the selection of another node and was enabled by the selection of another node How Key Shell Defines Softkeys Key Shell s pre defined softkeys are in the usr keysh C softkeys file Each softkey node has the following major components name Required The name is the command string that you type to access an invisible softkey It is also the default label for the visible softkey type Required for sub menu nodes The type defines whether
80. you want a listing of all the currently set options type set o Current option settings allexport off bgnice off emacs off errexit off gmacs off ignoreeof off interactive off keyword markdirs monitor noexec noglob nounset protected restricted trackall verbose vi viraw xtrace without options This could be a very lengthy list but should have some of these items listed 23 12 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in You can use the set command in other ways as in set third first second echo 1 2 3 23 third first second set s echo 1 2 3 first second third where set places the three values into the appropriate positional parameters and then sorts them and places them in the parameters in sorted order The typeset Command for Korn Shell only This command creates a shell variable assigns it a value and specifies certain attributes for the variable such as integer and readonly The syntax is typeset HLRZfilprtux n name value where name is the shell variable to be created value is to be assigned according to the options set The following example makes year readonly typeset r year 2000 echo year year 2001 ksh year is readonly Part Ill POSIX and Korn Shell Advanced Concepts 23 13 FINAL TRIM SIZE 7 5 in x 9 0 in 23 The following list of attributes may be specified by the de
81. your terminal for other work amp amp 1s kshre amp amp echo yes Separate commands such that the second kshre yes mail lsf No mail filet file2 file3 command only runs if the first one runs successfully that is its exit status is 0 In this example if the 1s fails to find the file then the echo is not executed Separate commands such that the second command only runs if the first one fails that is its exit status is not 0 In this example the 1sf lists the files only if the mail command fails 17 4 Shell Grammar Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Name Completion File Name Completion POSIX and Korn Shell both implement the C Shell feature file name completion File name completion allows you to type a unique subset of letters or abbreviation for a file name or path name followed by Esc Esc and the system matches and completes the name For example suppose you have a file name data_structure_3 for which you want a long listing type 11 data Esc Esc The system responds with 17 11 data_structure_3 rw rw rw 1 mary users 56 Sep 14 03 59 data_structure_3 It actually expands the name then executes the command upon receiving a Return If you have several files starting with data_structure_ such as data_structure_1 data_structure_2 and data_structure_3 the name expands to the longest common prefix of all names that match In
82. 1 O Aug 2 15 0 01 etc getty tty15 H O root 22024 1 OAug 2 14 0 02 f etc getty tty14 H O root 22023 1 O Aug 2 13 0 01 etc getty tty13 H O davek 22022 1 O Aug 2 12 0 08 sh The UID column refers to the user identifier the person who executed this process PID refers to the process identifier There are several commands which use the PID such as kill For example kill 9 28125 will kill terminate process 28125 the first entry in the above list PPID is the process identifier of the parent process the process that calls this process The first row shows 28124 as the parent process Look in the PID column for 28124 to see what the parent process is shown on the second row The C column shows processor utilization for scheduling STIME is the starting time of the process TTY is the controlling terminal for the process TIME is the cumulative execution time for the process and COMMAND is the command name For more details on the ps command see the HP UX Reference Before we begin the discussion on the Bourne Shell let us first define some terms Definitions The following are some definitions which will be used in this tutorial filename The name of a file command_list Either a line containing a command or several commands in a pipe or several lines containing commands pipes will be discussed later O Brackets used in a command syntax indicate the items enclosed are optional word A command name string A string of ch
83. 10 19 12 cd 16 8 16 10 18 1 24 7 CDPATH 16 9 16 10 characters escape 19 12 child process 17 2 chmod 21 1 chsh 16 3 clear 16 14 closing input output 17 10 COLUMNS 16 9 16 10 command 15 6 command interpreter 15 1 15 3 21 1 command line 15 6 command line editing 20 1 command mode 20 3 command precedence 23 7 command separators 17 3 command substitution 19 11 command terminators 17 3 command words types of 23 7 commenting 17 13 21 2 completing file names 17 5 17 6 path names 17 5 17 6 computer font 15 8 conditional statements 21 7 continue 24 9 continue statement 21 14 control key 20 4 controlling jobs 22 1 conventions 19 7 Index 2 coprocessing 17 2 23 4 creating aliases 18 1 creating jobs 22 1 creating scripts 21 1 C Shell 15 3 16 1 curly braces 21 1 curly brackets 19 7 21 18 customizing environment 16 4 D date 17 3 default aliases 18 3 18 8 default shell 16 3 default variables 16 12 defining rules aliases 18 6 division 21 15 double quotes 17 9 du 22 2 E echo 16 3 16 14 17 3 19 6 21 2 21 4 24 10 editing command lines 20 1 editing in line 20 4 editing lines 20 2 editing mode 20 1 20 2 EDITOR 16 6 16 9 16 10 20 2 20 4 ellipses 15 8 emacs 20 2 emacs in line editing mode 20 4 enabling emacs editor mode 20 4 enabling vi editor mode 20 2 ENV 16 4 16 7 16 9 16 10 18 3 23 1 environment 16 4 environmen
84. 10 1 cshrc File Commands Command Meaning set ignoreeof Traps CTRL D s to avoid accidental system log off Use the logout or exit command set prompt This command causes your C Shell prompt to be the current event number in square brackets followed by a percent sign This is very helpful when using the command history buffer set history 15 Sequentially keeps a buffer of your last 15 in this case events set savehist 15 This command saves the last 15 in this case events when you log off your system When you log back onto your system the event history is restored set noclobber This command stops C Shell from overwriting and destroying the information in an existing file Part Il C Shell Preparing to Use the Shell 10 7 FINAL TRIM SIZE 7 5 in x 9 0 in 10 You can suppress execution of the cshrc file by using the f option in the csh command as follows csh f The login Shell Script File When you activate C Shell by logging onto the system C Shell looks for the shell script file login in your home directory and executes it if it exists This shell script file contains global commands variables and parameters that you want executed or set up automatically at the beginning of your session Some of the commonly used commands you might want to include in this file and their meanings are shown below The term login_name refers to your login name Command Meaning setenv TERM hp2622 Sets the sys
85. 10 7 13 2 nonstandard functions aliases 12 1 notify 13 3 numeric shell variables 13 6 o operators arithmetic 13 6 operators assignment 13 7 operators boolean 13 7 operators logical 13 7 operators postfix 13 8 output metacharacters 12 8 P parent shell return to 10 4 path 13 4 postfix operators 13 8 previous events modifying 11 5 process number acquisition 14 12 prompt 13 4 prompt 10 7 Q quotation metacharacters 12 7 R re executing events 11 2 referencing events 11 2 rehash 14 2 rehash used to update path variables 13 4 relative location 11 3 repeat 14 2 restrictions on alias use 12 3 Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in return to parent shell 10 4 reusing command arguments 11 4 running C Shell from Bourne Shell 10 3 running scripts 14 9 S savehist 10 7 script execution 14 10 scripts 14 9 set 14 3 setenv 14 4 setting environment variables 10 6 setting shell variables 10 6 shell 13 5 shell script control structures 14 13 shell termination 10 4 shell variables 10 6 shell variable setting 10 6 shell variables numeric 13 6 source 14 4 startup C Shell 10 5 status 13 5 subshell 14 1 Part Il C Shell Index substituting aliases 12 2 substitution metacharacters 12 9 substitution of commands 12 4 switch 14 16 syntactic metacharacters 12 5 T terminating C Shell 10 4 10 9 then 14 1
86. 13 built in 15 6 23 6 23 7 built in commands 14 1 built in shell variables C Shell 13 1 c c 4 2 4 3 5 7 c 2 3 calling functions 21 18 cancelling a command 26 14 cancel special character meaning 5 7 C arithmetic operators 13 6 case 6 4 6 9 21 9 24 6 cat 17 3 17 10 19 12 catching interrupts 14 19 cd 16 8 16 10 18 1 24 7 cdpath 13 2 CDPATH 16 9 16 10 CDPATH environment variable 4 6 changing global configuration options 26 24 status line 26 26 changing event arguments 11 6 changing group identification 8 14 changing permissions 4 1 changing shells 1 4 1 5 characteristics terminal 26 3 characters escape 19 12 character special files 9 2 child nodes 27 4 child process 17 2 chmod 21 1 chmod command 4 1 choosing between shells 1 2 chsh 16 3 clear 16 14 closing input output 17 10 Master Index FINAL TRIM SIZE 7 5 in x 9 0 in COLUMNS 26 1 26 29 COLUMNS 16 9 16 10 combining shell commands 3 1 command 15 6 COMMAND 2 3 command arguments reusing 11 4 command customization 12 1 command grouping 8 2 command history buffer 11 1 command interpreter 2 1 15 1 15 3 21 1 command line 15 6 command line editing 20 1 command line editing 26 12 command mode 20 3 command precedence 23 7 commands 10 7 14 1 cancelling 26 14 editing 26 12 entering 26 4 26 8 formatting 27 21 HP UX 26 11 invisible softkeys 26 10 26 19 visible softkeys 26 9
87. 14 16 syntactic metacharacters 12 5 system prompt 4 5 system structure 2 2 15 1 system times 8 15 T tabs 4 5 tee 7 1 TERM 26 1 26 30 TERM 16 7 TERM environment variable 4 4 terminal characteristics 26 3 Terminal Session Manager and Key Shell 26 31 terminating commands 17 3 terminating C Shell 10 4 10 9 terminating the shell 16 13 test 21 7 24 33 test command 5 11 text adding to softkeys 27 19 formatting commands 27 21 help 27 20 Master Index FINAL TRIM SIZE Index hint 27 19 required 27 19 then 14 14 tilde 19 1 tilde substitution 17 13 19 1 time 14 5 24 35 times 8 15 24 36 TMOUT 16 10 16 12 topics online help 26 6 tracking aliases 18 3 translating a softkey command 27 8 word list 27 9 trap 16 8 16 14 23 16 24 37 trap command 8 11 trapping signals 23 16 TSM and Key Shell 26 31 two way pipes 17 2 21 2 21 6 23 4 type 23 6 type command 8 13 typeset 18 4 19 5 23 13 23 15 24 38 typographic conventions 25 5 TZ 26 30 U UID 2 3 ulimit 23 17 24 39 ulimit command 8 15 umask 24 40 unalias 14 6 18 8 24 41 unaliasing an alias 12 3 understanding Key Shell 27 1 undoing configuration changes 26 27 unset 14 6 24 42 unset command 8 11 unsetenv 14 6 unsetting aliases 18 8 until 6 3 21 12 24 45 user created parameters 5 2 user identifier 2 3 user times 8 15 using Index 13 7 5 in x 9 0 in Index HP UX commands 26
88. 21 9 FINAL TRIM SIZE 7 5 in x 9 0 in 21 Using the select Statement This is a command unique to the POSIX and Korn Shell It prints on the screen a set of words each preceded by a number It then prints the PS3 prompt and reads into the REPLY variable the line typed by the user If the contents of that line is the number of one of the listed words the value of parameter is set to the corresponding word If the line begins with anything else parameter is set to the null string Then regardless of whether the user s input matches one of the words the command_lines execute Within command_lines conditionals can trap the non matches If the user presses Return but has input nothing the command reprompts for input The loop continues until it encounters a break The syntax is select parameter in words do command_lines done In the following example all the colors in words are printed out with a number in front The default PS3 prompt 7 is printed and the shell waits for a number After Return is pressed it echos that the number s corresponding color is an RGB color and then prompts for the next entry It continues prompting until Break is pressed or it receives an interrupt If the input is 4 or anything that is not set to a color it returns is an RGB color without a preceding color name If the user presses Return _ but has input nothing the command reprompts for input 21 10 Basic Shell Programming
89. 27 3 27 3 27 6 27 8 27 9 27 10 27 12 27 13 27 13 27 14 27 15 27 15 27 16 27 18 27 19 27 19 27 20 27 23 27 23 27 24 Shells Figures 5 1 Shifting Positional Parameters 2 2 5 6 15 1 System Structure a 5 2 26 1 Key Shell Softkey Display a aaa a 26 2 26 2 Entering Commands Soe ee ee ee ee 26 8 26 3 After Selecting the Change Dir Softkey eaaa a 26 9 26 4 After Selecting the Parent Dir Option a aaa aa a 26 9 26 5 Using Invisible Softkeys e ee ee ee ee 26 10 26 6 Using Standard HP UX Commands Coe ee ee eee ee 26 11 27 1 Example Key Shell Node Hierarchy 2 2 a 27 2 Shells Contents 13 FINAL TRIM SIZE 7 5 in x 9 0 in Tables 1 1 1 2 3 1 3 2 4 1 5 1 8 1 8 2 8 3 8 4 10 1 10 2 11 1 13 1 16 1 17 1 17 2 17 3 17 4 21 1 21 2 23 1 24 1 25 1 26 1 26 2 26 3 26 4 26 5 26 6 Comparison of Shell Features Shell File Names and Default Prompts Redirection Symbols File Generation Symbols Shell Parameters Exit Status Options to the set Command _ Signals Parameters Set by the Shell Options for sh Command cshrc File Commands Logout Script Commands Previous Event Modifiers file_test Meanings Shell Parameters Separating and Terminating Characters File Name Substitution Metacharacters Quoting Metacharacters Input Output Redirect Operators echo Formatting Escape Sequences Operator Decreas
90. 4 time 14 5 U unalias 14 6 unaliasing an alias 12 3 unset 14 6 unsetenv 14 6 V variables accessing 14 11 W while 14 16 Index 3 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Part Ill POSIX and Korn Shell Introducing the Shells Starting and Stopping the Shell Shell Grammar Aliasing Abbreviating Commands Substitution Capabilities Command lines and Command History Basic Shell Programming Controlling Jobs Advanced Concepts and Commands Command Reference FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 15 15 Introducing the Shells This tutorial describes the POSIX Shell bin posix sh and the Korn Shell bin ksh POSIX Shell is based on the standard IEEE P1003 2 Korn Shell is the command interpreter human interface written by David Korn at AT amp T Bell Laboratories The tutorial covers the similarities and the differences between these two shells as well as the new features introduced in the POSIX Shell This tutorial addresses new users who are just learning shells as well as advanced users who are Bourne and C Shell experts New users should read all of this tutorial However at the beginning of each chapter advanced users will be directed to only the areas they need to concentrate on to come up to speed quickly Both classes of users should finish reading this section What is a Shell The kernel is the superviso
91. 5 in x 9 0 in 14 Comments Comment your script using the hash mark at the beginning of each comment line or command line that is to be ignored during execution The foreach Command The syntax for this statement is foreach index_variable loop_count_value_list command_1 command_2 end All of the commands between the foreach line and its matching end line are executed for each value in loop_count_value_list The variable index_variable is set to the successive values of loop_count_value_list Within this loop the break command can be used to stop loop execution while the continue command can be used to prematurely terminate one iteration and begin the next Upon completion of the for each loop the value of the iteration variable index_counter is the same as it was during the last loop in loop_count_value_list The if then endif Command This command has the following syntax if expression then command_1 command_2 14 14 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 14 endif Keyword placement is not flexible here due to current shell implementation That means the control structure has to be exactly as shown In other words if and then must be in the same line and endif must be in a separate line You can nest these statements using the keyword else For example if expression then command_1 command_2 else if expression then command_A command_B e
92. 6 18 who should use 25 4 keyshre file 26 3 26 28 KEYSIM 26 29 KEYTSM 26 30 Korn Shell 25 1 features 25 2 kshre file 26 3 L labels for softkeys 26 15 LINES 26 1 26 30 login program 26 3 mailers 26 17 mailx mailer 26 17 man page entries HP UX 25 5 menus softkey 25 3 26 2 messages error 26 5 moving softkeys 26 23 Part IV Key Shell N names for softkeys 26 15 navigation through softkeys 27 3 nodes attributes 27 6 components of 27 3 format of 27 4 hierarchy 27 2 navigation through 27 3 softkey 27 2 Index Oo online help 25 3 adding to softkeys 27 20 formatting commands 27 21 topics 26 6 using 26 6 options global configuration 26 24 softkey 26 4 26 9 26 10 status line 26 26 P PAGER 26 30 parameter softkeys 26 4 definition 27 4 PATH 26 30 placing softkeys 26 23 printing conventions 25 5 profile file 26 1 26 3 26 28 PS1 26 26 Q quitting Key Shell 26 2 R reference entries HP UX 25 5 removing softkeys 26 23 required text adding to softkeys 27 19 restarting Key Shell 26 27 Index 3 FINAL TRIM SIZE 7 5 in x 9 0 in Index S saving configuration changes 26 27 selecting softkeys 26 4 session switching TSM 26 31 setting shell variables 26 28 shell variables 26 1 26 28 COLUMNS 26 1 26 29 KEYBEL 26 29 KEYENV 26 29 KEYESC 26 29 KEYKSH 26 29 KEYLOC 26 29 KEYPS1 26 29 KEYSH 26 26
93. 7 12 8 12 9 12 10 scripts 14 9 startup 10 5 termination 10 9 cshre file commands 10 7 cshre shell script file 10 6 custom commands 12 2 customizing commands 12 1 cwd 13 2 E echo 14 1 endif 14 14 environment variable setting in C Shell 10 6 environment variables 10 6 evaluating file status 13 9 event arguments modifying 11 6 event number 11 3 events re executing 11 2 events referencing 11 2 event text 11 3 executing scripts 14 10 expansion metacharacters 12 9 expressions shell script 14 12 Index 1 7 5 in x 9 0 in Index F filename metacharacters 12 6 file status evaluation 13 9 foreach 14 14 G goto 14 17 H history 10 7 14 2 history substitution facility 11 1 home 13 2 l if 14 14 if then endif statements 14 14 ignoreeof 10 5 10 7 13 2 input metacharacters 12 8 input to commands 14 18 interrupts catching 14 19 J jobs 14 7 jobs 14 8 L logical operators 13 7 login shell 10 3 login shell script file 10 8 logout 14 2 logout command 10 5 metacharacters 12 5 12 9 metacharacters expansion 12 9 metacharacters filename 12 6 metacharacters input 12 8 metacharacters output 12 8 metacharacters quotation 12 7 metacharacters substitution 12 9 Index 2 metacharacters syntactic 12 5 metacharacters using as normal characters 12 10 modifying event arguments 11 6 modifying previous events 11 5 N noclobber
94. 8 3 G grave accent 5 8 group changing 8 14 grouping commands 8 2 H halting background processes 7 2 hash 8 12 home directory 4 5 4 6 HOME environment variable 4 6 if 5 10 5 15 6 9 IFS environment variable 4 6 input 3 2 5 12 9 3 input output 8 4 inserting commands 5 8 Internal Field Separators 4 6 internal memory 9 3 Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in interrupt signals 8 11 K kernel 2 1 9 3 kill command 2 3 L leaving shells 5 13 login scripts 4 3 loops 6 1 MAILCHECK environment variable 4 6 MAIL environment variable 4 4 4 6 MAILPATH environment variable 4 6 marker 8 5 matching patterns 3 6 message 9 3 message signals 8 11 multiplication 8 7 N n 4 3 5 7 network special files 9 2 newgrp command 8 14 nonsequential 9 3 nonsequential processing 3 2 number of positional parameters 5 4 Oo operating system 2 1 9 3 optional pieces in a pipe 7 2 options for set 8 10 options for sh command 8 18 options for shell commands 3 1 output 3 2 9 3 P parameter 3 2 9 3 parameter passing 5 5 Part I Bourne Shell FINAL TRIM SIZE Index parameter positional 5 4 parameters 4 3 5 2 5 3 parameter shell 5 2 parameters set by the shell 8 17 parameter substitution 5 3 parameter value definition 8 9 parent process 2 3 parse 9 4 passing parameters 5 5 path 9 4 PATH environment variabl
95. 9 Key Shell adding invisible softkeys 26 19 adding text to softkeys 27 19 27 20 adding visible softkeys 26 16 cancelling a command 26 14 configuring 26 15 creating custom softkeys 27 23 customizing 27 1 default environment 26 2 deleting softkeys 26 23 editing command line 26 12 editrules 27 8 27 9 edit statements 27 9 entering commands 26 4 error messages 26 5 exiting 26 2 features 25 2 global configuration options 26 24 HP UX commands 26 11 initialization 26 3 introduction 25 1 invisible softkeys 26 10 26 19 labels for softkeys 26 15 moving softkeys 26 23 names for softkeys 26 15 online help 25 3 26 6 27 21 overview 1 2 restarting 26 27 Master Index FINAL TRIM SIZE Index saving configuration changes 26 27 setting shell variables 26 28 shell variables 26 1 26 28 softkey attributes 27 6 softkey definition 27 3 softkey format 27 4 softkey menu 26 2 softkey menus 25 3 softkey navigation 27 3 softkey node hierarchy 27 2 starting 26 1 status line 25 3 26 2 26 26 Terminal Session Manager and 26 31 translating a softkey command 27 8 understanding 27 1 undoing configuration changes 26 27 using 26 4 visible softkeys 26 9 26 18 who should use 25 4 keyshre file 26 3 26 28 KEYSIM 26 29 KEYTSM 26 30 keyword parameters 19 4 19 5 kill 22 5 24 21 kill command 2 3 killing jobs 22 5 Korn Shell 25 1 definition 15 1 16 1 features 25 2 overview 1 1 ver
96. AL TRIM SIZE 7 5 in x 9 0 in 14 Undefined variable sumi h You can readily access the individual components of a variable that has several assigned values Thus echo sumi 1 echoes the first component variable of sumi In the example above a is echoed Similarly echo sumi sum1 returns the component variable sumi which is c echo sum1i 1 2 returns both a and b Other notations useful in shell scripts include n where n is a number which is a shorthand equivalent of argvn and returns the nth component variable of argv Another is x which is a shorthand for argv One minor difference between n and argv n should be noted argv n will yield an error if n is not in the range 1 through argv while n will never yield an out of range subscript error This is for compatibility with the way other shells handle parameters One way to avoid this type of error is to use a subrange of the form n If there are fewer than n component variables for the given variable an empty vector is returned A range of the form m n also returns an empty vector without giving an error when m exceeds the number of elements of the given variable provided the subscript n is within range Part Il C Shell Commands Jobs and Scripts 14 11 FINAL TRIM SIZE 7 5 in x 9 0 in 14 The form expands to the process number of the current shell Each process is unique so the process number can be used to generate uni
97. AL TRIM SIZE 7 5 in x 9 0 in 23 A discussion of other options follows a C m All subsequent parameters that are defined are automatically exported Prevents existing files from being overwritten by the shell s gt redirection operator The gt operator overrides this noclobber option If the shell is non interactive and if a command fails execute the ERR trap if set and exit immediately This mode is disabled while reading profile Disables file name generation Each command whose name is an identifier becomes a tracked alias when first encountered All parameter assignment arguments are placed in the environment for a command to use not just those that follow the command name Background jobs will run in a separate process group and a line will print upon completion The exit status of background jobs is reported in a completion message Read commands but do not execute them Sort the positional parameters Exit after reading and executing one command Treat unset parameters as an error when substituting Print shell input lines as they are read Print commands and their arguments as they are executed Turns off x and v flags and stops examining arguments for flags Do not change any of the flags This is also useful in setting 1 to a value beginning with If no arguments follow this option then the positional parameters are unset Using rather than causes these flags to be turn
98. C Shell Some POSIX and Korn Shell features similar to C Shell features are m History buffer and history substitution capabilities a File name completion a Command aliasing mechanisms m Arrays a Integer arithmetic evaluation m Tilde substitution m Job control features m Noclobber for 8 0 ksh88 Part Ill POSIX and Korn Shell Introducing the Shells 15 3 FINAL TRIM SIZE 7 5 in x 9 0 in 15 15 Differences from Bourne Shell The POSIX and Korn Shells are supersets of the Bourne Shell and contain all of the Bourne Shell s syntactic constructs and almost all of its semantics However POSIX and Korn Shell implement some features above and beyond those in the Bourne shell They are The select and function statements Built in commands such as alias bg fg jobs unalias Operators such as and gt Reserved words such as function and Substring expansions such as name patiern and namehpattern Expansion of position parameters greater than 9 digits Command substitution syntax command Assigning values with readonly and export Symbolic names for signals and traps IFS variable is effective only for read results of parameter expansions and command substitution It is always initialized Environment variable is passed to child process even if it is not exported for while and until loops are executed in the current process environment Assignments made within loops remain
99. C Shell Commands Jobs and Scripts 14 9 FINAL TRIM SIZE 7 5 in x 9 0 in 14 C Shell automatically executes the shell script file script_one If the first line in the file is not bin csh the Bourne shell will attempt to execute the shell script file instead Script Execution C Shell parses each shell script line into command arguments Each distinct command is identified and variable substitution is performed Keyed by the dollar sign character this substitution replaces the names of variables by their values Thus echo sumi when placed in a command script echoes the current value of the variable sum 1 to the shell script s standard output file An error results if sum has no value assigned To discover if a variable has a value currently assigned to it use the notation 7sum1 The question mark causes the expression to return the value one 1 if the variable has a currently assigned value and zero 0 if not This is the only available method for accessing a variable that does not have an assigned value without generating an error To determine how many component variables have been assigned to a variable use the notation sumi The hash sign notation returns the number of component variables assigned to the specified variable For example set sumi a b c echo sumi 1 echo sumi 3 unset sumi echo sumi 0 echo sum1 14 10 Commands Jobs and Scripts Part Il C Shell FIN
100. Connect Programs With Pipes The vertical bar is the pipe symbol Parameters for the program are listed after the program name but before the symbol Spacing between the program names and vertical bars is optional The syntax used for connecting programs with pipes is as follows program_a program_b program_c 3 4 Shell Commands Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in where word is a command or executable program Pipes operate on or transform data by separate programs in stages For example word_a might require input that you type from the keyboard word_a could collect this data and then direct it to stdout This output would be passed through the first pipe to become the input to word_b word_b might check that data for validity and process it in some way perhaps sort it The processed data would then go to stdout and be passed through the second pipe to become the input to word_c word_c might format that input into a report Here are some examples To print the number of files in the current directory type ls we To print a listing of each file in the directory and paginate it for convenient screen viewing type ls more To send the contents of file to pr which formats the data and then passes it to lp for printing on the line printer type cat file pr lp Redirection in Pipes The redirection symbols can be used for programs connected with pipes However only the data paths
101. FINAL TRIM SIZE 7 5 in x 9 0 in alias To track aliases in Korn Shell use alias t name such as alias t vi This tracks the full path of name the first time it is used and sets it in a special list of tracked aliases This speeds up the search time for commands Using set h sets automatic tracking on all commands See the set command for more details If PATH is changed interactively or in login scripts the tracked aliases become undefined To list tracked aliases use the alias t command without a name To export aliases in Korn Shell use alias x name such as alias x who who sort This exports name or who in this example for use by subshells Part Ill POSIX and Korn Shell Command Reference 24 3 FINAL TRIM SIZE 7 5 in x 9 0 in 24 24 bg Syntax bg 4n The bg command places job n where n is the job number in the background If n is not specified the current job is put into the background Example bg 1 This places the command defined to the shell by the job number 1 in the background See jobs for more information 24 4 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in break break Syntax 24 break n This command exits loops created by the keywords for while until or select If n is specified it breaks out of n nested loops Example for file in x y z none gt do gt if x file gt t
102. HE E HE HE HE HE HE HE This shell program copies all of the files in the current directory to the specified directory Usage To copy all files to a specified directory type the directory as the parameter To be prompted for file copy type the q option immediately following the gp command then the directory as the second parameter To include files in subdirectories use the d option FE HE HE FE HE HE FE HE HE HE FE HE HE FE HE HE PE FE E FE FE HE HE FE FE E FE FE E FE TE FE FE FE HE HE TE TE HE HE FE HE HE FE FE HE PE HE HE HE HE HE HE HE HE HE HE HE HE HE HE HE HH 1 test to make sure the directory parameter is included if eq O then echo gp opt to_directory echo Usage include options and a directory name echo options q query each file echo d include files in subdirectories exit 1 fi Part Bourne Shell Advanced Programming 6 9 FINAL TRIM SIZE 7 5 in x 9 0 in 2 look for options for i do case i in q query y 5 d dir y echo unknown option available options are q d exit 1 esac done newdir 1 3 test if parameter is a directory if d 1 then look to see if parameter is in current directory for g in do if 1 g then bool y fi done if parameter is in current directory fill in full path name if bool y then newdir pwd 1 fi 6 10 Advanced Programming Part I Bourne
103. IZE 7 5 in x 9 0 in 13 path The path variable is one of the most important variables in C Shell operation This variable contains a sequence of directory names C Shell searches for commands For example set path bin posix bin usr bin usr local bin usr bin etc or setenv PATH bin posix bin usr bin usr local bin etc PATH is a system variable and path is a C Shell variable that serves the same purpose The first is global while the second is local to the running shell When C Shell is first executed a hash table of command locations is created This table is created by looking through the directories specified in PATH except for the current working directory in the order specified by PATH Suppose you were to write one or more new commands and store them in one of the directories in your path other than your current working directory The system has no way of knowing they are there until you notify it of their presence by using the rehash command The hash table never gets built from commands in your current working directory so new commands put into don t affect the hash table But if your path contained HOME tools bin and you put a new command in there then rehash would add it to hash table The hash table also gets re built whenever your PATH is changed prompt This variable is used to customize your C Shell prompt For example set prompt 22 _ sets the prompt to indicate the
104. Index options 26 24 saving changes 26 27 status line 26 26 undoing changes 26 27 conventions printing 25 5 creating custom softkeys 27 23 custom softkeys 27 1 creating 27 23 format 27 4 D default environment for Key Shell 26 2 definition of softkeys 27 3 deleting softkeys 26 23 disabled softkeys 27 3 display of softkeys 26 2 E editing command line 26 12 editrules 27 8 27 9 append statement 27 12 blanks 27 14 combining expressions 27 11 dash statement 27 13 edit statements 27 9 examples 27 15 expressions 27 10 if statement 27 13 word list 27 9 edit statements 27 9 Index 1 7 5 in x 9 0 in Index elm mailer 26 17 enabled softkeys 27 3 entering commands 26 4 26 8 error messages 26 5 etc profile file 26 3 exiting Key Shell 26 2 F features Key Shell 25 2 Korn Shell 25 2 files etc profile 26 3 keyshre 26 3 26 28 kshre 26 3 profile 26 1 26 3 26 28 softkeys 26 16 26 19 usr keysh C keyshre 26 3 usr keysh C softkeys 26 16 26 19 27 3 format of softkeys 27 4 formatting commands for help text 27 21 function keys 26 2 G global configuration options 26 24 guidelines for using Key Shell 26 4 H help text adding to softkeys 27 20 formatting commands 27 21 hierarchy of softkey nodes 27 2 navigation through 27 3 hint text adding to softkeys 27 19 HP UX commands 26 11 HP UX Reference 25 5 Index 2 initialization of
105. NAL TRIM SIZE 7 5 in x 9 0 in 11 11 Command History The Command History Buffer csh maintains a Command History Buffer capable of holding one or more of your most recent commands By setting the history variable to some integer value the history buffer can hold many commands These saved commands sometimes called events can be accessed in many useful ways Commands can be quite complex so the term event is used to refer to commands stored in the Command History Buffer from now on A buffer size of 10 to 20 is about right for most situations You can make use of the history buffer by using the C Shell history substitution facility which enables you to use words from previous commands as parts of new commands repeat command events repeat arguments from a previous command in the current command event and fix spelling and typographical errors in previous events History substitutions begin with an exclamation point and cannot be nested To see how this all works place the following lines in a file named cshre or login in your home directory set history 15 set savehist 15 set prompt 4 These commands m create a fifteen event Command History Buffer m save the last 15 events in your command history buffer when you log off the system and restore them the next time you log on the system m cause your C Shell prompt to display the event number of each event Part il C Shell Command History 11
106. Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in select color in red green blue gt do gt echo color is an RGB color gt done 21 1 red 2 green 3 blue 7 1 green is an RGB color 4 is an RBG color Break Using the for Loop The for loop allows you to execute a command_line once for every new value assigned to a parameter in a specified list Syntax is for parameter in list do command line done In the following example the first time through the loop the for statement sets file to x and prints it out The second time through the loop y is printed out and the last time z is printed out When the list is completely finished the loop is exited for file inx yz gt do gt echo The file name is file gt done Part Ill POSIX and Korn Shell Basic Shell Programming 21 11 FINAL TRIM SIZE 7 5 in x 9 0 in 21 Using the while until loops This loop continues executing command_line and processing through the list as long as the item in list continues to evaluate true Once an item evaluates false the loop is exited The syntax is while list do list done Note The until loop is similar to the while loop and has the same basic syntax However it executes until a nonzero status is returned the while command executes until a zero status is returned Also the until loop always executes at least once The loop in the following example initializes the
107. RANDOM 15314 SECONDS 0 SHELL bin ksh START L O users mary kshrec TERM hp2392 TMOUT 0 TZ MST7MDT VISUAL vi For an explanation of each of these see Table 16 1 Shell Parameters and Chapter 23 At this time it is not important that you understand each of these shell variables completely These definitions will become clearer as you become familiar with the POSIX and Korn Shell Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 9 FINAL TRIM SIZE 7 5 in x 9 0 in 16 Table 16 1 Shell Parameters Parameter Definition dash underscore CDPATH COLUMNS EDITOR ENV FCEDIT IFS Continued on next page Represents the number in decimal of positional parameters supplied to a shell script Represents the flags or options supplied to the shell on invocation or by other commands Represents the decimal value exit value returned by the last executed command Represents the process number of the last invoked shell Note that it is not reset for parenthesis subshells Represents the process number of the last background process invoked Represents the last argument of the previous command line for Korn Shell only The search path for the cd command This parameter when set defines the width of the edit window for the shell edit modes vi emacs gmacs and for printing lists from the select command When the VISUAL parameter is not set and the
108. Shell FINAL TRIM SIZE 7 5 in x 9 0 in 4 begin main loop for f in do if f 1 then test if file is a directory or regular file Part I if a f then test if query option is used if query y J then prompt user to respond y to copy or anything else to ignore echo copy f c read copy test if user wants file copied if copy y then cp f newdir echo f copied to newdir fi else query option not used cp f newdir echo f copied to newdir fi else test for d option if dir y then Bourne Shell Advanced Programming 6 11 FINAL TRIM SIZE 7 5 in x 9 0 in test if user wants to copy from subdirectories echo copy subdirectory files from f c read dcpy if dcpy y then if query y then curdir pwd cd f gp q d newdir cd curdir else curdir pwd cd f gp d newdir cd curdir done 5 parameter is not a directory else echo 1 is not a directory exit 1 fi 6 12 Advanced Programming Part I FINAL TRIM SIZE 7 5 in x 9 0 in Bourne Shell Discussion of Example Groupcopy Since this is a rather lengthy example we have provided comments throughout to explain its function The example is really a new command you can use and you may find it quite useful The example called gp groupcopy copies files from one directory into another This will save you time in typing each file individually as you copy
109. Shells User s Guide HP 9000 Computers L HEWLETT PACKARD HP Part No B2355 90046 Printed in USA August 1992 Second Edition E0892 FINAL TRIM SIZE 7 5 in x 9 0 in Notices The information contained in this document is subject to change without notice Hewlett Packard makes no warranty of any kind with regard to this manual including but not limited to the implied warranties of merchantability or fitness for a particular purpose Hewlett Packard shall not be liable for errors contained herein or for direct indirect special incidental or consequential damages in connection with the furnishing or use of this material Copyright 1983 91 Hewlett Packard Company Reproduction adaptation or translation without prior written permission is prohibited except as allowed under the copyright laws Restricted Rights Legend Use duplication or disclosure by the U S Government is subject to restrictions as set forth in sub paragraph c 1 ii of the Rights in Technical Data and Computer Software clause in DFARS 252 227 7013 Hewlett Packard Company 3000 Hanover Street Palo Alto CA 94304 U S A Rights for non DOD U S Government Departments and Agencies are as set forth in FAR 52 227 19 c 1 2 Use of this manual and flexible disk s or tape cartridge s supplied for this pack is restricted to this product only Additional copies of the programs may be made for security and back up purposes only Resale of the
110. TH The colon separated search path for mail_files The shell informs you of mail arriving in any file in the list within the time specified by MAILCHECK If you follow each mail_file in the search path with a question mark the message immediately following the appears on the screen instead of the default message PATH The search path for commands PPID The process number of the parent of the current shell If you execute ps f you will see this number under the PPID heading Associated with this PPID is a PID which is the current process number PS1 Defines the primary prompt string for a shell The default is If you precede the with the character the primary prompt string includes the number of the current command PS2 Secondary prompt string by default gt used on command or script continuation lines Continued on next page Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 11 FINAL TRIM SIZE 7 5 in x 9 0 in 16 16 Shell Parameters continued Parameter Definition PS3 The prompt string used with the select command by default PWD The present working directory set by the last cd command OLDPWD The previous working directory set by the last cd command RANDOM This parameter generates a random integer when referenced REPLY This parameter is set by the select and read commands when no arguments are supplied on the select command line Instead the PS3 prom
111. This input redirection operator uses the file gt amp digit output descriptor specified by the descriptor digit Most programs have standard input as 0 stdin standard output as 1 stdout and standard error as 2 stderr The more commonly used redirection is gt amp digit In the example standard output 1 is redirected to standard error 2 The 1 is optional in this example lt amp echo no output gt amp These operators close standard input and gt amp output respectively Part Ill POSIX and Korn Shell Shell Grammar 17 11 FINAL TRIM SIZE 7 5 in x 9 0 in 17 17 The order in which you place redirections is significant The shell evaluates each redirection in terms of the file descriptor associated with each file at the time of the evaluation For example 2 gt fname 1 gt amp 2 This command line first associates the file descriptor 2 stderr with fname This sends stderr file descriptor 2 to the file frame instead of the terminal It then associates file descriptor 1 stdout with the file associated with file descriptor 2 which is fname The echo command prints to stdout but now stdout points to stderr which has been redirected to a file This means both standard output and standard error are put in fname If you wanted to know what files in a large directory started with a particular letter you might direct both stdout in case files were found and stderr in case files were not found to the s
112. _ 0 _ _ 44 i Let s look at each part of this expression _ 1 This creates a parameter named _ and assigns it a value of 1 The value of this expression is the value of the assignment namely 1 Note since parameter substitution is performed on this expression the name of the variable will look something like ism To see this try echo see what flags are ism echo _ _ism echo _ism no variable _ism defined yet C_ 1 create and assign to _ism 23 2 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in echo _ism 1 now _ism has a value _ 0 Set parameter named _ to 0 we need this since we may reference _ in the next step The value of 23 this expression is 0 _ _ 7 i This expression checks to see if a parameter named _ remember this is _ism in our example and we have set it to 1 in the first expression has a different value than the parameter named on the right hand side of the operator That parameter name will be either _ or _ _ism depending on the expansion of 7 i The latter will evaluate to null for an interactive shell and to _ for a non interactive shell So for an interactive shell we have _ _ which is true value arithmetically speaking is 1 and for a noninteractive shell we have _ _ _ which is false value for the expression is 0 Adding it all
113. a parameter 8 9 SHACCT environment variable 4 6 sh command 4 1 8 18 sh command options 8 18 shell 13 5 shell 9 5 15 3 16 1 SHELL 16 3 16 10 16 12 shell command 3 1 shell command options 3 1 shell command parameters 3 1 SHELL environment variable 4 6 shell expansions 6 7 shell features 1 3 shell file names 1 4 shell parameters 4 6 5 2 16 4 shell parameters variables 16 10 16 11 16 12 shell programming 5 1 shell programming advanced 6 1 shell programming special commands 8 7 shell prompts 1 4 shell script 4 1 5 1 21 1 21 18 shell script control structures 14 13 shell termination 10 4 shell variables 4 3 10 6 16 4 26 1 26 28 COLUMNS 26 1 26 29 KEYBEL 26 29 KEYENV 26 29 Index 11 FINAL TRIM SIZE 7 5 in x 9 0 in Index KEYESC 26 29 KEYKSH 26 29 KEYLOC 26 29 KEYPS1 26 29 KEYSH 26 26 26 29 KEYSIM 26 29 KEYTSM 26 30 LINES 26 1 26 30 PAGER 26 30 PATH 26 30 PS1 26 26 setting 26 28 TERM 26 1 26 30 TZ 26 30 shell variable setting 10 6 shell variables numeric 13 6 sh_history 16 10 20 5 shift 5 5 24 32 shifting positional parameters 19 5 signals 8 11 23 16 simple command 15 6 single quote 5 8 single quotes 17 9 slash back 17 9 softkeys adding invisible 26 19 adding text 27 19 27 20 adding visible 26 16 attributes 27 6 backup 27 23 cancelling a command 26 14 components of 27 3 creating custom 27 23 custom 27 1 de
114. a time when you need a pipe with an optionally inserted piece In other words you wish to execute a c if one condition exists and a b c if another condition exists To do this consider the following example optional if condition then optional b fi eval a optional c If condition is true optional becomes b and thus the eval statement executes a b c Otherwise a c is executed You can also use this same idea in optional redirection statements Halting Background Processes If you are running several background processes and a foreground process you may wish to be able to terminate all processes at the same time instead of using the kill command for each This may be helpful for instrumentation related work Let s say you wish to use the Break key to terminate three processes the one in the foreground terminated automatically and two in the background Here is a script which would accomplish this 7 2 Programming Tips Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in initialize the process list proc echo starting process 1 process1 add process number to list proc proc echo starting process 2 process2 add process number to list proc proc the BREAK key will kill everything trap kill proc trap 2 exit 2 echo starting process 3 foreground process process3 The first line initializes a parameter proc
115. acters cannot be used directly as parts of command arguments Thus the command echo does not echo the character It will either echo a sorted list of file names in the current working directory or print the message No match if there are no files in the working directory To handle metacharacters as normal characters put them between single quotes The command echo will echo an asterisk to your display Three metacharacters cannot be escaped with single quotes m the exclamation mark m the backslash m the single quote The backslash must be used to cancel the special shell meaning of these metacharacters Thus echo PAL prints E l These two mechanisms the single quote and the backslash let you use any printable character in a shell command They can be combined as in echo which prints 2k The backslash escapes the first single quote and the asterisk was enclosed between single quotes The result is a single quote and asterisk 12 10 Aliases Substitution Metacharacters Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 13 13 Shell Variables Built In Shell Variables C Shell maintains a set of variables that can be assigned values by the set command Shell variables are useful for storing values for later use in commands The most commonly referenced shell variables are however those which the shell itself refers to By changing the values of these
116. acters for command and parameter substitution because they will be interpreted if not quoted Notice it does not just look for the word marker but rather the line containing only the word marker lt lt is particularly useful for multi line input to commands usually ed 1 commands It is also useful because it eliminates in many cases the need for separate input files If you add the optional after lt lt then all leading tabs in the here document are stripped lt amp digit This input redirection symbol uses the file descriptor associated with the descriptor digit Most programs have standard input as 0 standard output as 1 and standard error as 2 stdin stdout and stderr respectively All programs which work properly with pipes observe 0 and 1 and consequently 2 Other programs may not Part I Bourne Shell Detailed Reference 8 5 FINAL TRIM SIZE 7 5 in x 9 0 in gt amp digit is the format for using descriptors where digit can be any single digit 0 9 The most commonly used redirection of this form is 1 gt amp 2 or 2 gt amp 1 For example echo File name not found 1 gt amp 2 The output of this line is redirected to the standard error your terminal So in effect you are creating your own error message and redirecting it in the same manner as an error from the shell You can use this capability to ensure messages in a shell file reach the user In the same manner 2 gt amp 1 merges the standa
117. ame if r backup i t then if the file is not in the backup directory then echo i t not in backup not cp ed print an error message and continue continue with the next file endif echo compare two files i and backup i t cmp s i backup i t compare the two files if status 0 then if the file has changed echo making new backup of i cp i backup i t make a new copy of it in the backup directory endif end 14 20 Commands Jobs and Scripts FINAL TRIM SIZE 7 5 in x 9 0 in Part Il C Shell Index Index A accessing variables 14 11 alias 14 1 aliases 12 1 alias substitution 12 2 alias unaliasing an 12 3 alias use restrictions 12 3 altering event arguments 11 6 argv 13 1 arithmetic operators C 13 6 assignment operators 13 7 autologout 13 1 boolean noclobber 13 2 boolean notify 13 3 boolean operators 13 7 Bourne Shell running C Shell from 10 3 built in commands 14 1 built in shell variables C Shell 13 1 c C arithmetic operators 13 6 catching interrupts 14 19 cdpath 13 2 changing event arguments 11 6 command arguments reusing 11 4 command customization 12 1 command history buffer 11 1 commands 10 7 14 1 commands custom 12 2 Part Il C Shell FINAL TRIM SIZE command substitution 12 4 comments 14 14 control structures 14 13 creating custom commands 12 2 C Shell 10 1 10 3 commands 14 1 metacharacters 12 5 12 6 12
118. ame output file In the following example no files starting with the letter g were found but there was one file starting with the letter j ls g 2 gt fname 1 gt amp 2 ls j 2 gt gt fname 1 gt amp 2 more fname g not found jg900401 hpg 17 12 Shell Grammar Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Other Metacharacters A few other metacharacters to be aware of are and m You can can insert comments into shell scripts by using the symbol when it is the first character in a word Any following words are treated as comments until a new line occurs e g This is a comment This is explained in Commenting in Chapter 21 m The tilde substitution symbol allows path name substitution and is explained in Tilde Substitution in Chapter 19 a The symbol allows job number substitution and is discussed in Putting Jobs in Background Foreground in Chapter 22 and under bg fg and kill in Chapter 24 Part Ill POSIX and Korn Shell Shell Grammar 17 13 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 18 18 Aliasing Abbreviating Commands Aliasing is a method by which you can abbreviate long command lines or cause standard commands to perform differently by replacing the original command line with a new command called an alias The new command can be a letter or short word when typed but will expand to the old command line when used
119. and without the user having to press Return By default you must press to execute a command The line option 1 automatic in a softkey definition means that when you select 4 a Return is included and the command executes automatically editrule editrule An editrule for this softkey node which defines how it is translated into an HP UX command Editrules are discussed in the section titled How Key Shell Translates a Softkey Command hint string The one line hint for this softkey node displayed when the softkey is selected Hints are only valid for string type softkey nodes Hint messages are discussed in the section titled Adding Text to Softkeys required string The one line error message for this softkey displayed if you do not select a required softkey or type a required string Required messages are discussed in the section titled Adding Text to Softkeys help helptezt The help message for this softkey It can be more than one line long Help is discussed in the section titled Adding Text to Softkeys How Key Shell Translates a Softkey Command When you have entered a complete softkey command and pressed Insert line or Return keysh translates the command into HP UX syntax by applying the editrules associated with each of the selected softkey nodes Editrules are part of the attributes of a softkey node They tell keysh
120. and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Path Name Completion This expansion process completes directory paths in a similar manner such that 11 users m ESC ESC expands to 17 11 users mary This only works if you provide a unique identifier after the File Name Substitution File name substitution is a quick and easy way to match file names without typing the full name File name metacharacters represent character patterns which are replaced with a matching file name pattern on execution of the command Suppose you wanted to long list the file data_structure_3 again type 11 data_structure_3 or use a metacharacter and type 11 data_ which matches any character or string of characters starting with data_ If there is more than one file starting with data_ they are all listed Table 17 2 File Name Substitution Metacharacters lists and gives examples using the metacharacters used in pattern matching Part Ill POSIX and Korn Shell Shell Grammar 17 7 FINAL TRIM SIZE 7 5 in x 9 0 in 17 Table 17 2 File Name Substitution Metacharacters Meta Example Description character ls prog Matches almost any single character The 1s prog a command lists all files starting with prog and prog c ending with any other letter such as prog c prog o and prog o 1s p Matches almost any string of characters p o including the null string The 1s command pattern mat
121. and name other options and parameters by blanks Parameters or variables are data the command needs to function properly If you omit parameters from the 1s command the current directory is listed But if you include a directory name or path name as a parameter a listing of that directory is printed Command syntax usually takes the following form command options parameters Sequential Processing When you enter commands line by line pressing Return after each command you are telling the system to complete the command or program before executing the next command Executing date ps ef who will complete each command before going on to the next You can place all of the commands on the same line by using the separator For example date ps ef who Part I Bourne Shell Shell Commands 3 1 FINAL TRIM SIZE 7 5 in x 9 0 in is equivalent to entering each command on a separate line This process is called sequential processing New programs or commands cannot be started until the preceding program or command has completed If parameters are required by the program they are entered as usual The semicolon is placed after the last parameter While a program is running as a sequential process there is no response to keyboard activity until after the program has completed other than the keyboard buffer delay Programs already in progress when a program with sequential processing is executed con
122. ands softkey options appear Using standard HP UX commands Each of these methods is described below Figure 26 2 shows how you can use any of these methods to perform the same task Using a visible softkey command Using an invisible TASK softkey command RESULT Key Shell changes Change to the arent director you to the i i cd parent directory Using a standard HP UX command cd Figure 26 2 Entering Commands 26 8 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Using Visible Softkey Commands To use the visible softkey commands select the softkey command then select any options Press Return to execute the command or to see the command line translated into HP UX syntax keysh notifies you if you forget to supply any required information For example to see how basic softkey command entry works follow these steps 1 After starting keysh select the Change dir softkey Your screen should look like that in Figure 26 3 Notice that the softkeys 26 have now changed to show the options available for the Change Dir command Change_dir Jf hpfcjdp fusers jodi Wo mail 03 44 35 PM Figure 26 3 After Selecting the Change Dir Softkey 2 Select the parent dir option from the softkey options 3 Press Insert line The readable softkey command you created is now translated into HP UX syntax but the command has not bee
123. aracters Part Bourne Shell The Bourne Shell 2 3 FINAL TRIM SIZE 7 5 in x 9 0 in Conventions This tutorial contains computer underline italic bold 2 4 The Bourne Shell several different types of fonts Computer fonts are used in screen printouts for actual command names and file names and in examples to show anything you are to type i e varname penguin means you type the entire string Underline designates actual user response in a computer dialogue If you see italic font in command examples it refers to something you need to substitute for the italicized word s i e varname variable_name means you actually type varname but you have to substitute a variable name in place of variable_name Italics also indicate text being emphasized text to which you should pay particular attention Bold font indicates a term used for the first time in the chapter Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in 3 Shell Commands This chapter will discuss methods for combining shell commands You should already be familiar with executing single commands like running the date command In addition to simply typing a command and pressing Return you have the ability to include options and parameters to the command Options to a command can be found in the HP UX Reference under the description of the command These options are usually preceded by a dash and are separated from the comm
124. art Ill POSIX and Korn Shell Substitution Capabilities 19 11 FINAL TRIM SIZE 7 5 in x 9 0 in 19 However using the first syntax simplifies nesting in substitution For example echo echo echo hello hello echo echo echo hello hello Back quotes cause substitution of the output of the echo command and echo is repeated twice in the second command line The backslash cancels the second back quote from closing the echo Therefore the third echo is evaluated and outputs the hello The first command line performs the same function in a less complicated manner Any valid shell script may be put in command substitution The shell scans the line and executes any command it sees after the opening quote or parenthesis until a matching closing quote or parenthesis is found For example echo Users logged in on this date n date who Fri Sep 11 16 43 34 MDT 1987 mary console Sep 11 09 01 michael tty09 Sep 11 10 35 For POSIX and Korn Shell there is another special command substitution for the cat command Normally you type echo n cat file and the contents of file are displayed This quicker and shorter form produces the same results echo n lt file This shortened form outputs the entire file as a single line of text echo lt file 19 12 Substitution Capabilities Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in 20 20 Command lines and Comman
125. as you learn shell programming techniques Here is a sample profile file PATH docs tools bin usr bin usr contrib bin users hpux davek PATH PATH usr local bin users hpux davek bin d1 usr informix bin PATH PATH d1 usr informix 1lib d1 usr informix MAIL usr mail LOGNAME TERM 2623 export TERM PATH MAIL HOME stty kill c stty sane tabs T TERM if mail e then echo Part Bourne Shell Shell Scripts 4 3 FINAL TRIM SIZE 7 5 in x 9 0 in echo You have mail echo fi The script sets some essential definitions for shell variables and makes them global to the system For example the PATH variable sets up a search path for commands When you execute a command in the shell it looks at the PATH parameter The PATH parameter gives the shell several directories in which to look for the command If you execute a program that is not in one of the directories specified by PATH you will receive an error message Let s go line by line and describe the entries in this sample profile file PATH sets up the search path for the shell Each directory in the path is separated with a colon Once the shell has read this profile any command you execute is searched for first in the docs tools directory then the bin directory and so on Notice the last entry in the first line is a dot This indicates the current directory at the time you execute the command whatever that happens to be The second and third
126. ases have been assigned When executed without command line arguments all currently defined aliases are printed If an argument is provided the alias of that argument is printed For example alias ls shows the current alias if there is one for the directory list command 1s The echo Command The echo command prints its arguments to the shell s standard output file unless redirected the standard output is your display Echo often used in shell scripts to print information about what is happening in the script For example echo Your mail is sent could be used in a mailing script to inform you that mail created by the script has been sent Part Il C Shell Commands Jobs and Scripts 14 1 FINAL TRIM SIZE 7 5 in x 9 0 in 14 The history Command The history command will show the contents of the history list Numbers are assigned to each history event and can be used to reference previous events that may be difficult to reference using contextual mechanisms discussed previously The shell variable called prompt can be defined with an exclamation point included in its definition so that the number being assigned by the history buffer is also displayed as part of normal terminal activity This provides an easy way to reference previous commands and re execute previous events To set the prompt variable use a command similar to the following set prompt Note that the character had to be
127. aster Index FINAL TRIM SIZE 7 5 in x 9 0 in repeat 14 2 replace current shell 8 7 REPLY 16 10 16 12 21 2 21 10 required text adding to softkeys 27 19 reserved word 15 6 23 6 23 7 restarting Key Shell 26 27 restricted Bourne Shell 4 6 8 18 restrictions on alias use 12 3 return 21 19 24 29 returning from functions 21 19 return to parent shell 10 4 return values 8 16 reusing command arguments 11 4 rksh 16 12 rsh 8 18 running commands at the same time 3 2 running C Shell from Bourne Shell 10 3 running scripts 14 9 running sequential commands 3 1 running shell programs 4 1 S savehist 10 7 saving configuration changes 26 27 screen 9 4 script execution 14 10 script file 9 5 scripts 14 9 21 1 searching for a command 8 12 secondary prompt 4 6 5 1 SECONDS 16 10 16 12 select 16 11 16 12 21 10 24 30 selecting softkeys 26 4 separating commands 17 3 sequential 9 5 sequential processing 3 1 4 2 8 1 session switching TSM 26 31 set 8 9 14 3 16 8 16 9 16 12 16 13 18 3 19 6 20 2 20 4 22 3 23 1 23 9 23 12 24 31 Master Index Index set command options 8 10 setenv 14 4 setting aliases 18 1 setting environment shell variables 16 4 setting environment variables 10 6 setting kshre 16 8 setting parameters 19 4 19 5 19 6 setting profile 16 6 setting shell variables 10 6 26 28 setting the environment 4 3 set value of
128. ation of the associated device These files normally reside in the dev directory disk A platter for recording and storing information A disk can be either a flexible disk or a hard disk In this manual when the term disk is used alone it refers to a hard disk driver number A pointer to the part of the kernel needed to use the device The driver number is used in the mknod command when setting up a device file editing Making changes in a file containing text data or a program Part Bourne Shell Bourne Glossary 9 1 FINAL TRIM SIZE 7 5 in x 9 0 in environment System defaults which affect shell operation execution Carrying out the instructions of a program or command file A collection of computer information program or data residing on a mass storage medium e g a hard disk file types Several file types are recognized The file type is established at the time of the file s creation The types are Regular files Contains a stream of bytes Characters can be either ASCII or non ASCII This is generally the type of file a user considers to be a file object code text files nroff files etc Directory Treated as regular files with the exception that writing directly to directories is not allowed Directories contain information about other files Block special files Device files that buffer the I O Reads and writes to block devices are done in block mode Character special files D
129. atus of all 1p printers ls Lists the contents of a directory mailx Processes electronic mail interactively make Maintains updates and regenerates groups of programs man Accesses the online manual pages mkdir Creates a new directory more Displays the contents of a file one screen at a time nroff Formats text for printing od Creates an octal dump of a file paste Merges the same line in several files or subsequent lines of one file Pg Displays the contents of a file one screen at a time pr Formats text for printing Part IV Key Shell Getting Started With Key Shell 26 21 FINAL TRIM SIZE 7 5 in x 9 0 in 26 26 Table 26 4 Invisible Softkey Commands continued Softkey Function ps Shows the status of active processes remsh Executes a command on a remote host rlogin Connects your terminal to a remote host rm Deletes files or directories rmdir Deletes directories sdiff Compares two files and displays a side by side listing of any differences set Sets shell options shar Bundles one or more files into a shell archive package sort Sorts the lines of a file tail Displays the last ten lines of a file tar Creates maintains and accesses a file archive on tape tcio Improves data transfer rate to cartridge tape Commonly used with cpio 1 tee In a command pipeline copies data passing between commands to a file touch Updates the access modification and change times of a file tr Translates characte
130. ay 42 alias cd cd ls Using a command statement in the alias of the command is acceptable The entire alias definition is placed inside single quotes to prevent interpretation of the semicolon as a metacharacter and to avoid unwanted substitutions Part Il C Shell Aliases Substitution Metacharacters 12 1 FINAL TRIM SIZE 7 5 in x 9 0 in 12 12 The backslash in front of the exclamation point prevents the exclamation point from being interpreted as a history substitution As a result the string substitutes the entire argument list to the pre aliasing cd command The semicolon separates the cd and 1s commands so that they are executed sequentially Creating Custom Commands C Shell s alias facility can also be used to create new commands Suppose you want to get a long alphabetical listing of your current working directory showing the size of each file You could type in ls als each time but you want to make up your own command dir and get the same results To do this type in alias dir ls als Alias Substitution After a command line is scanned it is parsed into distinct command arguments The first word of each command left to right is checked to see if it has an alias If it does the alias string replaces the aliased word The process begins again The substituted alias string is marked to avoid looping and does not modify the rest of the command word s arguments Alias an
131. ccent is under the tilde 7 Command substitution means you can substitute a shell command s output into a string like the echo string The command is a shell command and must be enclosed between grave accents 5 8 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in The following example shows a command substitution in an echo command with the output from the command substitution appearing on the same line as the echoed words echo The current date and time is date This command will print something similar to the following The current date and time is Wed May 30 15 24 35 MDT 1990 The following example shows a command substitution in an echo command with the output from the command substitution appearing on lines following the line with the echoed words echo People currently on the system n n who This command will print something similar to the following People currently on the system billa console May 30 09 45 stu tty02 May 30 12 02 jth tty03 May 30 07 24 michael tty04 May 30 12 31 clarke tty07 May 30 08 15 richard pty ttypo May 30 12 19 If you need to quote characters within grave accents make sure you use a different quote character than the enclosing quote In the following we use double quotes to enclose the entire string and single quotes within the grave accents echo The banner command n banner banner Part Bourne Shell Basic Shell Pr
132. ce you cannot perform more than one type of search at a time If you selected the keyword search option the required line then prompts you for the required information the keyword s to search for Since multiple key words are 27 allowed this node is not disabled after it is selected keysh then appends the keyword argument s to the command line If you select the file search option keysh appends a f to the command line All other options are disabled since you cannot perform more than one type of search ata time If you selected the file search option the required line then prompts you for the required information the file name s to search for Since multiple file names are allowed this node is not disabled after it is selected keysh then appends the argument s to the command line If you select the from section option you must select an option for the manual section to search keysh then appends the corresponding HP UX option to the command line If you select the user_commands option all other options at this level are disabled since you can only choose one section to search Other section options are omitted here to save space Unless you disabled the lt topic gt node by selecting either the keyword search or file search nodes you must also specify the topic to search for keysh then appends this argument to the command line Customizing the Key Shell 27 17 FINAL TRIM SIZE 7 5 in x 9 0
133. ch that name will be interpreted by the shell The syntax is whence v name e The flag v produces a more verbose report When name is a reserved word function or builtin command the shell returns the command name If the command has an alias the alias is displayed If neither of these is true the full path name is printed If name is not found the shell so indicates whence v type type is an exported alias for whence v This example discovers that type is actually an exported alias for whence v So just type type type type is an exported alias for whence v 23 6 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The following example shows how the different commands are interpreted this gt pr int that 23 gt whence while true alias this file fffile while alias this usr bin file whence v while true alias this file fffile while is a reserved word true is an exported alias for alias is a shell builtin this is a function file is usr bin file fffile not found The first part of this example defines a function this then asks whence to explain a series of six different words that might be used as commands Part Ill POSIX and Korn Shell Advanced Concepts 23 7 FINAL TRIM SIZE 7 5 in x 9 0 in 23 This first five words of the set demonstrate the five types of command words the shell understands and presents them in Korn Shell
134. characters 16 10 17 9 16 10 17 13 19 7 19 10 21 2 19 7 16 3 17 9 19 7 C 19 11 19 10 19 10 16 2 16 3 17 13 19 7 22 4 hh 19 7 22 4 t 22 4 22 4 amp 17 3 22 3 amp amp 17 3 17 9 19 11 21 18 17 7 19 10 16 10 lt 17 10 lt lt 17 10 gt 17 10 gt gt 17 10 16 10 17 7 19 7 19 10 CJ 21 7 22 1 17 9 17 9 19 11 3 19 7 21 1 21 18 15 6 17 1 18 1 l amp 17 2 21 2 21 6 23 4 Part Ill POSIX and Korn Shell FINAL TRIM SIZE Index A abbreviating commands 18 1 accessing arrays 21 17 accessing history file 20 5 20 10 20 12 addition 21 15 alias 24 2 alias 15 6 16 8 23 6 23 7 alias command 18 1 aliases default 18 3 18 8 defining rules 18 6 exported 18 3 tracked 18 3 unsetting 18 8 aliasing 18 1 aliasing features 18 6 argument 15 6 arithmetic evaluation 21 15 array 19 10 21 17 automatically set variables 16 12 background jobs 22 3 background process 16 10 17 3 back quotes 17 9 19 11 back slash 17 9 bg 22 3 24 4 bin csh 16 1 bin ksh 15 1 16 1 bin posix sh 15 1 16 1 bin sh 16 1 blank 15 6 Index 1 7 5 in x 9 0 in Index bold 15 8 Bourne Shell 15 3 16 1 16 3 brackets 15 8 17 7 21 7 22 1 break 24 5 break statement 21 13 built in 15 6 23 6 23 7 c calling functions 21 18 case 21 9 24 6 cat 17 3 17
135. characters 24 10 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in eval eval Syntax 24 eval arg This command is unique because the command_line is scanned twice by the shell First the shell interprets the command_line when it passes the args to the eval command and then interprets it a second time as a result of executing the eval command Consequently you can execute command_lines that normally would not be possible as shown next Example cmd ps ef gt ps out eval cmd When eval is executed the shell has already expanded cmd so it runs ps ef and redirects the output to file ps out If eval was not used redirection or pipes would not be interpreted by the shell after parameter substitution Part Ill POSIX and Korn Shell Command Reference 24 11 FINAL TRIM SIZE 7 5 in x 9 0 in 24 exec Syntax exec arg The exec command replaces the current shell with the new shell or program specified by args without spawning a new process or subshell Example exec 2 gt dev null This example redirects the the shell s standard error to dev null where it is ignored by the shell exec ps ef From vi it is possible to run ps ef without wasting time spawning another process Using causes vi to pass the command exec ps ef to the shell for interpretation and then exec causes the shell to execute ps in place of itself 24 12 Command Re
136. command event number of the current command This is very useful when using the History mechanism 13 4 Shell Variables Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in shell Some HP UX commands such as mailx and vi spawn a new shell when they begin execution while others may spawn one or more new shells during normal operation If the program or command is written so that it recognizes the shell variable you can set the variable to define the type of shell to be spawned by the program For example set shell bin csh selects C Shell while set shell bin posix sh selects POSIX Shell This technique is valid only if the command or program recognizes that uses the variable when spawning new shells Be careful when using the shell variable The result may or may not be what you intended status This variable returns 0 if the most recently executed command was completed without error A non zero value means an error was detected Part Il C Shell Shell Variables 13 5 FINAL TRIM SIZE 7 5 in x 9 0 in 13 13 Numeric Shell Variables The at command assigns a value to a numeric variable name just as the set command assigns a string to a nonnumeric variable name Numeric values can be decimal integers For example 22 sum 1 4 23 echo sum 5 24 sum 01 012 25 23 echo sum 13 26 Numeric Expressions Numeric expressions evaluated by are very similar t
137. cs presented on paper in Using HP UX Part Ill POSIX and Korn Shell Introducing the Shells 15 9 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 16 Starting and Stopping the Shell New users should read this whole chapter Experienced users can skip to the section on Setting Up profile and kshre Getting Started Login When you log in on a system a program called login determines whether your user name and password are correct by checking the file etc passwd The etc passwd file is a special system file that contains a listing of all the valid users and encrypted versions of their passwords on a system See your System Administrator for more details or passwd 4 Once you type the correct user name and password the login program starts spawns a shell POSIX Shell bin posix sh is the default shell on newly delivered systems so you can begin executing system commands HP UX supports three other shells Bourne bin sh Korn Shell bin ksh and C Shell bin csh Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 1 FINAL TRIM SIZE 7 5 in x 9 0 in 16 16 Command Line When the shell is ready for your next command it displays a prompt on the terminal display screen Commands are given to the shell by typing the command name followed by options and or parameters called command arguments as appropriate for that command and pressing the Return key The defa
138. ctory Example cd This command transports you from your present working directory PWD to your home directory HOME which becomes the new PWD cd The transports you to the previous PWD which is contained in OLDPWD cd otherdir This use of otherdir changes the working directory from the present working directly to another directory contained underneath the same parent In other words change to parent then to otherdir contained in the parent of the current directory cd bin cd usr This example changes your present working directory to bin Then it replaces the old directory with the new directory usr and transports you to usr bin Part Ill POSIX and Korn Shell Command Reference 24 7 FINAL TRIM SIZE 7 5 in x 9 0 in 24 cd CDPATH HOME work HOME src cd aardvark In this example the present working directory changes to HOME src aardvark unless there is a directory named PWD aardvark or HOME work aardvark The first line sets CDPATH to a list of directories to be searched if a full path name is not given to cd So when you type the second line in the example the shell first checks for PWD aardvark then for HOME work aardvark 24 8 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in continue continue Syntax 24 continue n This command skips any lines following it in a for while until or select loop and restarts
139. cuted The second line executes the previous command which just happens to be fc 1 so the last 16 commands are displayed again fc 1 ps This lists all the commands in the history file that have been executed since the last ps fc e cd 1s cd This command _line causes the replacement of cd with 1s in the most recently executed command in the history file which contains a cd After the replacement the new command_line is executed See Chapter 20 for a detailed explanation of fc Part Ill POSIX and Korn Shell Command Reference 24 15 FINAL TRIM SIZE 7 5 in x 9 0 in 24 fg Syntax fg n The fg command places job n the job s number currently running in the background or suspended in the foreground The current job is put into the foreground if n is not specified Example fg 1 This places the command defined to the shell by the job number 1 in the foreground See jobs for more information 24 16 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in for for The for loop allows you to execute a command_line once for every new value assigned to a parameter in a specified list 24 Syntax for parameter in list do command_line done Example for file inx yz gt do gt echo The file name is file gt done the first time through the loop the for statement takes the file x and prints it out The second time through the loop y is pri
140. d type sh scriptname Where scriptname is the name of the file you placed the command line in Part I Bourne Shell Shell Scripts 4 1 FINAL TRIM SIZE 7 5 in x 9 0 in The common way to run a script or program however is to declare the file executable with the chmod command chmod is used to alter the permissions on a file For our purposes we will declare the file to be executable by everyone on the system but only you can update the file Type chmod x scriptname Now the file is executable and you only need enter the file name to run the script simply type the scriptname as if it was a command Your script will execute and you will see a large output Both methods of executing scriptname have the same net effect they just behave differently at first For details on the chmod command see the HP UX Reference Scripts With More Than One Line The example above just uses one command line for the script You can however make the script easier to read and contain more than one line of commands Each line of commands is executed in sequential order the previous line must complete before the next line is executed So we can take the previous example date who ps ef du users and spread the command line into four lines which accomplish the same thing date who ps ef du users When this script is executed you get the same results as before Echo and Redirection in Scripts If you have a large output fro
141. d History Editing Command lines Typing a long command line finding a mistake after executing it re typing the command and finding another mistake can be very frustrating Command line editing allows you to correct mistakes in a command line before executing the command If you are a new user all of these sections are of interest to you if you are an advanced user some of the new features of vi supported by the POSIX and Korn Shell and the fc command may be of interest Part Ill POSIX and Korn Shell Command lines and Command History 20 1 FINAL TRIM SIZE 7 5 in x 9 0 in 20 Using In line Editing Modes There are two types of editing modes available in POSIX and Korn Shell the vi mode and the emacs mode A discussion of each of these methods follows These Shell editing modes emulate the corresponding editors and all common commands are the same In line editing is very similar to using the editor in that in line editing uses the common editor s commands Using vi Line Edit Mode The vi editing mode uses the same commands as the vi editor If you are unfamiliar with the vi editor see Using HP UX or The Ultimate Guide to the vi and ex Text Editors Enabling vi Line Edit Mode There are several ways to enable the vi editing mode One is to type set o vi For further details on the set command see Chapter 23 Another is to set and export the VISUAL shell variable in your profile or kshrc to a value endin
142. d an example Each example is explained This reference is written for the intermediate or advanced user who has a firm understanding of shell concepts whether it be Bourne Shell C Shell POSIX Shell or Korn Shell It is meant as a quick reference or refresher for the basic commands used in the Korn Shell Part Ill POSIX and Korn Shell Command Reference 24 1 FINAL TRIM SIZE 7 5 in x 9 0 in 24 alias Syntax For POSIX Shell only alias word command Lee For Korn Shell only alias tx word command a The alias command defines word to mean command such that when word is used command is executed This is useful for shortening long command lines to one or two letters Example alias unpro chmod w unpro myfile In this example unpro is shorthand for aliased to chmod w Saying unpro myfile adds write permission to myfile alias cd mycd cd there cd here The first statement declares cd to be an alias for a function defined elsewhere called mycd The next line changes the working directory to there using that function Using backslash causes the last line to perform a real cd not the function form to the directory here Note that quoting the first word in any way prevents it from being interpreted as an alias Just typing alias lists on the screen all the current shells default and set aliases 24 2 Command Reference Part Ill POSIX and Korn Shell
143. d can be used to prompt the user for input see read or to indicate something has been done You can also use parameter substitution in the echo command One helpful item for the echo command is the c backslash c If you add c to the end of an echo statement the default linefeed is suppressed This means you can prompt the user to input on the same line see the example at the end of this section Another helpful item is n which adds an extra new line For further information on the echo command see the echo 1 entry in the HP UX Reference Quoting Since the shell is full of special characters with special meanings we need a way to suppress the meaning of a special character If we have a string which contains a special character we may not want it treated as such If you were to assign a string of characters to a parameter and the characters contained blanks and characters with a dual meaning blanks in this case would indicate the end of the parameter assignment you may receive an error message When you quote a character or string of characters with single quotes you suppress any special meaning Other quote marks have different effects The Backslash The backslash will cancel or escape the special meaning of the next character echo dir1i will echo dir1 instead of the parameter value of diri because the dollar sign is told to have no special meaning In this example the has been
144. d the history facility both use the same substitution scheme A single exclamation point represents the current event and is preceded by a backslash so that the shell does not interpret it but instead passes it on to alias History modifiers also work in alias statements 12 2 Aliases Substitution Metacharacters Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 12 Alias Use Restrictions There are two basic restrictions that you must adhere to when using the alias facility a Although you can alias the alias command to be called something else you cannot alias any command to be called alias If you attempt to do so an error message is generated m To prevent the formation of an alias loop C Shell allows a particular alias string to appear only once in another alias definition Also the command that is being aliased can appear only once in its own alias definition For example 32 alias ls alias works but 33 alias ls ls ls does not If you try to execute 1s after it has been aliased with event 33 above you see 34 1s Alias loop 35 Unaliasing an Alias Assume that when you type alias at the prompt the following aliases are active in your shell Your system administrator might have created them or you could have added them to your cshrc file yourself 41 alias cd cd ls h history print pr lp W who echo You are who am i dir ls als To unalias
145. d_line1 is executed if it is not conditional_cmd_line2 is executed Example if x passwd then echo Welcome to Korn Shell else echo Please log off fi if checks whether the value of x is equal to passwd If so the first echo line is printed otherwise the second line is printed Part Ill POSIX and Korn Shell Command Reference 24 19 FINAL TRIM SIZE 7 5 in x 9 0 in 24 jobs Syntax jobs 1 p job_id a To list all the jobs currently running in your shell including job number and status use the jobs command Using the 1 option lists the process ID directly after the job number as well Using the p option displays the process IDs of the selected jobs Example sleep 20 date amp jobs jobs 1 This example puts a date program in the background to execute in 20 seconds and then looks at the waiting job using the two different command versions 24 20 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in kill kill Syntax For POSIX Shell only 24 kill s signal_name process_id kill 1 exit_status For Korn Shell only kill signal process_id This command cancels kills the designated process_id using signal if specified signals are specified by number or name as explained in the signal 2 entry in the HP UX Reference If signal is not specified kill uses a default signal 15 SIGTERM which causes software terminatio
146. ds 6 Using Invisible Softkey Commands 26 10 Using Standard HP UX Commands 26 11 Editing the Command Line 2 2 2 26 12 Configuring Key Shell woe eee ee ee 26 15 Adding Moving and Deleting Softkeys woe eee ee ee 26 15 Softkey Names and Labels 2 2 ee 26 15 Adding Visible Softkeys 2 2 2 1 2 1 26 16 Adding Invisible Softkeys 2 2 2 2 2 26 19 Shells Contents 11 FINAL TRIM SIZE 7 5 in x 9 0 in Moving Softkeys Deleting Softkeys Changing Global Options Changing the Status Line Saving Configuration Changes Restarting Key Shell Undoing Configuration Changes Setting Shell Variables Using Key Shell with Terminal Session Manager 27 Customizing the Key Shell Understanding Key Shell How Key Shell Stores Softkey Information Softkey Navigation How Key Shell Defines Softkeys Softkey Attributes How Key Shell Translates a Softkey Command Editrules Expressions Append Statement Dash Statement If Statement Blanks Examples of Editrule Use Remove Files Command Line Example Man Softkey Example Cat Softkey Example Adding Text to Softkeys Adding Required and Hint Text Adding Help Text Creating Custom Softkeys Backup Softkeys Examples Index to Part IV Key Shell Master Index Contents 12 FINAL TRIM SIZE 7 5 in x 9 0 in 26 23 26 23 26 24 26 26 26 27 26 27 26 27 26 28 26 31 27 1 27 2
147. e s output when possible Some output is based on the files existing in the current directory so your output will not match exactly the output shown in the examples unless you create the files The examples in this chapter use the following commands Command Definition cat concatenates copies or prints files date prints the current date echo prints the arguments that follow the command 11 prints a long listing of detailed information about files lp sends files to the printer ls lists the files in the current directory mail reads your mail or sends mail to another user more prints a file out for viewing on the display ps lists your current processes who lists the people logged into the system whoami prints the current user s name Part Ill POSIX and Korn Shell Shell Grammar 17 3 FINAL TRIM SIZE 7 5 in x 9 0 in 17 Table 17 1 Separating and Terminating Characters Character Example Description whoami 1s Separates commands that are executed in george sequence In this example 1s is executed file1 only after the whoami command completes file2 file3 amp lp prog c amp Indicates that the command is to be executed 1 4094 as a process asynchronously That means you request id is lp 725 can run other commands immediately on the echo hello terminal while the previous command runs hello invisibly to you in the background This sends the file prog c to the line printer to be printed while freeing up
148. e 4 4 4 6 path name 3 3 9 4 pattern matching 3 6 permission 4 1 9 4 PID 2 3 pipe 3 4 3 5 7 2 9 2 9 4 positional parameters 5 4 print accumulated user and system times 8 15 print commands as shell is executed 8 10 process 9 4 process identifier 2 3 process parent 2 3 profile customizing 4 5 profile file 4 3 program 9 4 programming shell 5 1 prompts 4 6 PS1 environment variable 4 5 4 6 PS2 environment variable 4 6 5 1 ps command 2 2 Q quoting 5 7 R read 5 12 readonly command 8 14 redirecting combined output 8 3 redirecting input 3 2 Index 3 7 5 in x 9 0 in Index redirecting output 3 2 redirection 3 2 3 5 4 2 8 4 9 4 regular files 9 2 remainder 8 7 replace current shell 8 7 restricted Bourne Shell 4 6 8 18 return values 8 16 rsh 8 18 running commands at the same time 3 2 running sequential commands 3 1 running shell programs 4 1 S screen 9 4 script file 9 5 searching for a command 8 12 secondary prompt 4 6 5 1 sequential 9 5 sequential processing 3 1 4 2 8 1 set 8 9 set command options 8 10 setting the environment 4 3 set value of a parameter 8 9 SHACCT environment variable 4 6 sh command 4 1 8 18 sh command options 8 18 shell 9 5 shell command 3 1 shell command options 3 1 shell command parameters 3 1 SHELL environment variable 4 6 shell expansions 6 7 shell parameters 4
149. e left unprocessed Input Output Metacharacters lt name indicates redirected input from name For example mail boss lt memo amp sends the file memo to the boss gt name indicates redirected output For example grep vn filel filel gt numbered filel puts a copy of filet with each line numbered in the new file numbered file1t This metacharacter causes the target file to be overwritten gt amp name directs the diagnostic output along with the standard output into the file name gt name redirects output with overwrite of target file This is used when noclobber is set gt gt name redirects output by appending it to the end of name If the file name does not exist and the variable noclobber is set an error occurs gt gt amp name appends diagnostic output along with the standard output to the end of name gt gt name Acts like gt gt except in the case where name does not exist and the noclobber variable is set In such a situation gt gt creates name and no error occurs lt lt word reads the shell input up to a line which is identical to word Word is not subjected to variable file name or command substitution and each input line is searched for word before any substitutions are performed on it Files are processed in this manner are commonly called here documents 12 8 Aliases Substitution Metacharacters Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 12 forms a pipeline between two proce
150. e characters converted to lowercase The uppercase flag u is turned off p The output of this command if any is written onto the two way pipe r The given names are marked readonly and these names cannot be changed by subsequent assignment 23 14 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in t Tags the name Tags are user definable and have no special meaning to the shell u All lowercase characters are converted to uppercase characters This turns the lowercase flag 1 off 23 xX The given names are marked for automatic export to the environment of subsequently executed commands Using rather than causes these flags to be turned off If no name arguments are given but flags are specified a list of names and optionally the values of the parameters which have these flags set is printed Using rather than keeps the values to be printed If no names and options are given the names and attributes of all parameters are printed The following example covers some of the attributes set above typeset i arg1 3 arg2 22 echo arg1l arg2 typeset export PATH readonly year typeset u up letters echo up LETTERS Part Ill POSIX and Korn Shell Advanced Concepts 23 15 FINAL TRIM SIZE 7 5 in x 9 0 in 23 The trap command The scope of the trap command is much broader than the following explanation suggests but here is one of its uses Many ti
151. e how long execution of a specified command requires When time is followed by a command name argument the command is executed then time displays user system and execution time for the command If no argument is used with the time command equivalent information about the current shell and any child processes it has created is printed instead For example time cp file file2 0 0u 0 1s 0 01 8 time we file file2 52 178 1347 filed 52 178 1347 file2 104 356 2694 total O 1u 0 18 0 00 13 4 indicates that the copy command cp used a negligible amount of user time u and about 1 10th of a system second s the elapsed time was 1 second 0 01 The wordcount command wc used 0 1 seconds of user time and 0 1 seconds of system time in less than a second of elapsed time The percentage 13 indicates that over the period when the command was active it used an average of 13 percent of the available cpu cycles of the machine Part Il C Shell Commands Jobs and Scripts 14 5 FINAL TRIM SIZE 7 5 in x 9 0 in 14 The unalias Command The unalias command is used to remove aliases that have been assigned to the current shell For example if the alias command was used to cause the change directory command cd to print the working directory pwd each time it was called alias cd cd pwd then unalias cd cancels the assigned definition and cd is again interpreted as the standard HP UX command The unset Command Thi
152. e in the name of the file s c in this case keysh appends the argument to the HP UX command line verbatim Customizing the Key Shell 27 15 FINAL TRIM SIZE 7 5 in x 9 0 in 27 Man Softkey Example This example shows the complete softkey definition for the man command which lets you access the online HP UX Reference manual pages The man command is assigned the label Manual page in the keyshre file 27 16 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in softkey man command editrule append man option keyword_search disable all editrule append k string lt keys gt disable 1 editrule append argument required Enter the keyword s to search the manual page entries for option file_search disable all editrule append f string lt files gt disable 1 editrule append argument required Enter the file name s to search the manual page entries for option from_section option user_commands disable all editrule append 1 required Select amanual section string lt topic gt editrule append argument required Enter the name of the manual topic Part IV Key Shell When you type man or select Manual page keysh appends man to the HP UX command line If you select the keyword search option keysh appends a k to the command line All other options at this level are disabled sin
153. e problems with positional parameters Let s think of the positional parameters as a stack with 1 at the bottom and 9 at the top if there are more than nine parameters the remainder would be stacked on top Part I Bourne Shell Basic Shell Programming 5 5 FINAL TRIM SIZE 7 5 in x 9 0 in Shift will remove the value of 1 and replace it with the value of 2 move the value of 3 to 2 and so on It is like removing the bottom entry of the stack and letting the values fall one position down Let s look at a graphic representation of this idea Before Shift After Shift Figure 5 1 Shifting Positional Parameters You can use shift in loops which we will discuss next or you can use it sequentially like in the following example named list if 1 yes then shift cat 1 exit else shift echo file called 1 was rejected fi If the first positional parameter 1 is equal to yes then the contents of the filename the second positional parameter will be listed The first time 1 is used for the test it may have the value yes After the shift the value that was 2 is shifted to 1 and 1 would be the file name To execute this script you would type list yes filename or even list no file2 5 6 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Echo We have already mentioned the echo command as a method to display text on the screen The echo comman
154. e softkey invisibly Part IV Key Shell Getting Started With Key Shell 26 23 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Changing Global Options This section explains the global configuration options found under the Keysh config options softkey menu Global options allow you to control such things as which type of softkeys are available for use whether HP UX translations are displayed and whether prompts are given In the Keysh config options menu an asterisk next to an option name means that the option is on Global configuration options can be turned on and off with the following commands Keysh config options option_softkey on Keysh config options option_softkey off For example to turn off the prompts use this command Keysh config options prompts off Retum 26 24 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 26 5 describes the global options Table 26 5 Global Options Option Default Description help Enabled If you set help to off the Help softkey disappears but online help is generally still available by using the key invisibles Enabled If you set invisibles to off keysh will not recognize invisible softkey commands prompts Enabled If you set prompts to off keysh will not display prompt messages describing actions that are required to complete the current softkey command selectors Disabled If you set
155. ecifying the function name and the argument list function exef 21 if x 1 then echo 1 is executable fi for file in ls do exef file done where exef file is the function call Returning from a Function Occasionally you need to return from a function with an exit status The return command s syntax is return n This command stops execution of the function and returns to the calling procedure with an exit status of n If n is not specified the returning status is that of the last command executed within the function When return is invoked outside the boundaries of a function it acts as an exit The first line of the following example defines a function named search which checks a given file for a string xxx This function inverts the normal return value of grep Therefore if the string is found the function returns 1 Otherwise if the string is not found or the file is not readable it returns 0 Part Ill POSIX and Korn Shell Basic Shell Programming 21 19 FINAL TRIM SIZE 7 5 in x 9 0 in 21 search if grep xxx 1 gt dev null 2 gt amp 1 then return i else return 0 fi A ANN NNN GB search myfile A recursive function is a function that repeatedly calls itself It terminates when the last call to the function returns a special value the function is testing for For example suppose the file fact contained a recursive function The the second call to fact wi
156. econds If set to 0 the shell will check before each prompt MAILPATH The search path for mail files The shell informs the user when mail arrives PS1 Primary system prompt The default is PS2 Secondary system prompt The default is gt IFS Internal Field Separators which are normally space and tab SHACCT Write an accounting record in the writable file set by this parameter SHELL If an r is contained in the basename last entry in a path the shell becomes a restricted shell Note example profile file See The profile File section earlier in this chapter for an 4 6 Shell Scripts Part I FINAL TRIM SIZE 7 5 in x 9 0 in Bourne Shell 5 Basic Shell Programming Once you have mastered simple shell scripts you can do more complex shell programming This chapter introduces ways to pass information to a shell program how to execute commands conditionally and how to get data from the keyboard during the execution of a shell program All of the constructs of shell programming can be executed in two ways you can type the commands into a file so they will all be executed when the file name is entered after changing the permission or you can enter the commands directly into the shell just as you enter commands like date When you enter shell constructs directly into the shell you can either type them on the same line and press return to execute them
157. ecuted The second command sequence is then executed in the background due to the terminating amp The second test is performed and if unsuccessful the sort is performed Command Grouping You can group a sequence of commands together using parentheses or braces If you group a series of commands with parentheses a sub shell is created to run the commands who 1s This command grouping is executed separately from the current shell program The current shell program only sees the results of the command grouping The advantage of command grouping is you can place a series of commands in the background or use other command separators to achieve a variety of results Here s another example test f file amp amp cat file gt temp sort o temp temp lp temp rm temp amp 8 2 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in This command sequence will test if file is an ordinary file If it is it runs a command grouping in the background note the terminating amp This command line could be simplified to read test f file amp amp sort o lt file pr lp Another helpful way to group commands is with braces This command grouping is used primarily for redirecting combined output You can group a series of commands together and use the resulting output date ls who gt contents All of the commands in the braces are executed and the resulting output
158. ecuting when the program is done you return to the current shell s environment If you wish to have the shell program executed in the current shell and thus make the defined variables good for the current shell s environment use the dot command seripiname Make sure there is a space between the dot and the script name otherwise the system will assume it is part of the script name Let s look at an example Create a file with the following commands echo dog dog tired echo dog Make the script executable with the chmod command chmod x dogsample where dogsample is the name of the script Next define the variable dog to be dog rover Part Bourne Shell Advanced Programming 6 5 FINAL TRIM SIZE 7 5 in x 9 0 in Run the script by typing dogsample without the dot command The results will be rover tired Now check to see what the value of dog is echo dog rover The original value for dog appears This is because the shell was executed in a subshell Now try the dot command dogsample rover tired and then test the value of dog echo dog tired The value of dog was changed because the script was run in the current shell The eval Command The eval command reads its arguments as input to the shell and the resulting commands are executed The format is eval arg vee where arg is one or more arguments which are shell commands o
159. ed if not Goodbye is printed x hello if x hello then echo Welcome else echo Goodbye fi Welcome In the following example the files in the current directory are tested using brackets around the expression Using x tests for an executable file If the test returns true the executable file s name is printed for file in ls gt do gt if x file gt then echo file is executable gt fi gt done 21 8 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Using the case Statement The case statement allows you to easily check conditions and then process a command line if that condition evaluates to true The syntax is case string in 21 pattern pattern command list1 pattern3 patternf command list2 esac The first line receives a string which is checked against each of the patterns to see if it matches If the pattern matches the command line directly following is executed For example i in r rmdir dir1 echo directory removed echo option o echo not a valid option The case statement first checks i against each option for a match If it matches d or r the directory is removed the specifies logical or If it matches o or all others an appropriate response is printed If the string does not begin with no action is taken Part Ill POSIX and Korn Shell Basic Shell Programming
160. ed off 23 10 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in These flags are the same ones used to invoke the shell ksh h or bin posix sh h 23 which causes the shell to create a tracked alias for every command executed The POSIX and Korn Shell implement an option o that turns on the specified argument or option i e set o option Many of these options correspond to the above letters that perform the same function without using o The following argument or option can be one of the following option names allexport Same as a errexit Same as e emacs Puts you in an emacs style in line editor for command entry gmacs Puts you in a gmacs style in line editor for command entry ignoreeof The shell will not exit on end of file The command exit must be used keyword Same as K markdirs All directory names resulting from file name generation have a trailing appended monitor Same as m noexec Same as n noclobber Same as C for POSIX Shell noglob Same as f nounset Same as u verbose Same as v trackall Same as h vi Puts you in insert mode of a vi style in line editor until you press the key This puts you in a mode so you can move on the line A Return executes the line viraw Each character is processed as it is typed in vi mode xtrace Same as x Part Ill POSIX and Korn Shell Advanced Concepts 23 11 FINAL TRIM SIZE 7 5 in x 9 0 in If
161. eference 24 39 FINAL TRIM SIZE 7 5 in x 9 0 in 24 umask Syntax For POSIX Shell only umask s nnn For Korn Shell only umask nnn This command sets the user s file creation mask to the string nnn unless nnn is omitted then the current value of the mask is displayed Example umask 022 If this line was in your profile it would set your process umask value to 022 which means a file created later will be 644 rw r r rather than 666 rw rw rw or 755 rwxr xr x instead of 777 rwxrwxrwx Actually saying umask 022 does not cause the execute x bits to be turned off because they are normally not turned on at create time but later by chmod calls chmod is discussed at greater length in the book Introducing UNIX System V by Morgan and McGilton Note The POSIX Shell provides the S uppercase option to the umask command This option prints the mask in the symbolic mode If this mode is specified as mask the permissions and will be interpreted relative to the current file mode creation mask The causes the bits to be cleared in the mask and the causes the bits to be set 24 40 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in unalias unalias Syntax 24 unalias name This command reverses the affect of the alias command on name and removes it from the alias list Example alias cd cd ls unalias cd This c
162. el Cancels a print request cat Concatenates and displays files cd Changes the current directory cdb C programming language symbolic debugger chatr Changes a program s internal attributes chgrp Changes the group of a file chmod Changes the permissions of a file chown Changes the owner of a file cmp Compares two files and notifies you of any differences col Used with nroff 1 to filter reverse linefeeds and backspaces comm Prints all the lines common to two sorted files cpio Copies file archives cut Cuts selected fields or columns from a file dd Copies a tape or file df Displays the number of free 512 byte blocks and free inodes on a file system diff Compares two files and notifies you of any differences dircmp Compares two directories and notifies you of any differences disable Disables 1p printers du Displays disk usage for files or directories 26 20 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 26 4 Invisible Softkey Commands continued Softkey Function elm Processes electronic mail interactively enable Enables 1p printers exit Terminates the shell find Locates files within a directory fold Wraps text lines that exceed maximum width grep Searches for lines matching a pattern head Displays the first ten lines of a file jobs Displays all active jobs kill Terminates a process lp Sends files to an 1p printer or plotter lpstat Shows current st
163. ell 16 7 23 1 invoking a shell 16 3 I O redirect 17 10 italics 15 8 Index J job control 22 1 job number 22 4 job number substitution 17 13 jobs 22 1 background 22 3 controlling 22 1 creating 22 1 foreground 22 3 killing 22 5 monitoring 22 1 suspending 22 2 jobs 22 1 24 20 K kernel 15 1 keyword parameters 19 4 19 5 kill 22 5 24 21 killing jobs 22 5 Korn Shell definition 15 1 16 1 versus other shells 15 3 Index 3 7 5 in x 9 0 in Index ksh flags 23 11 Kshrc 16 4 16 7 16 8 21 1 23 1 L let 21 15 24 23 limits process 23 17 LINES 16 9 16 11 list 15 6 11 17 3 logging in 16 1 logging out 16 14 login program 16 1 Logout 16 14 loop for 21 11 until 21 12 while 21 12 lp 17 3 1s 17 3 17 7 18 3 Isf 17 3 M mail 17 3 17 10 MAIL 16 6 16 9 16 11 MAILCHECK 16 9 16 11 MAILPATH 16 9 16 11 matching file names 17 7 matching patterns 19 7 21 9 metacharacter 15 6 17 1 17 7 17 9 17 13 modes command 20 3 20 4 emacs 20 4 enabling 20 2 20 4 gmacs 20 4 input 20 3 20 4 vi 20 2 modularization 21 18 monitoring jobs 22 1 more 17 3 multiplication 21 15 Index 4 N name 15 6 named parameters 19 4 19 5 not equal 21 15 number job 22 1 process 16 1 o OLDPWD 16 9 16 12 options 15 6 16 10 23 9 23 10 23 11 23 13 23 14 output standard 17 10 outputting data 21 2 21 4 21 6 P parameter 15 6
164. ending on your terminal type you may be able to use the identify 1 command to check these variables and set them correctly m TERM must be set to the terminal type you are using m If your terminal is a non standard size such as an X window the LINES and COLUMNS variables must be set to the correct values for the terminal Part IV Key Shell Getting Started With Key Shell 26 1 FINAL TRIM SIZE 7 5 in x 9 0 in 26 To start Key Shell do one of the following 1 If you want to use keysh temporarily type this command keysh Return Return to your regular shell by typing exit Return 2 If you want to use keysh permanently type this command chsh your_username usr bin keysh Then log out and log back on again From now on whenever you log on keysh is your shell The Default Key Shell Environment When you first start keysh you will see a display like that in Figure 26 1 E hpfcjdp users jodi keysh No mail 03 43 09 PM i More 1 of 4 Figure 26 1 Key Shell Softkey Display The parts of this display are as follows 1 The first line shows the standard Korn Shell prompt 2 The second line is the status line By default it displays the host name current directory mail status and time 3 The third line shows the top level softkey menu Each softkey corresponds to a function key on your keyboard f1 through fg The hpterm at the center separates the keys
165. er word Linder amp string Simple assignment Add and assign Subtract and assign Concatenate and assign Simple assignment Add and assign Subtract and assign Concatenate and assign x argument xt 1 x x amp argument word x egrep word last 1 word last word last amp v Append Statement The append statement is used to add a string to the command being built It has this format append string The append statement causes string to be appended as a new word in the word list immediately after the last word For example this editrule appends cp to the command line when you select Copy files softkey Copy_files command editrule append cp In the following example the required line prompts the user to type the dest the name of the destination file or directory This user supplied argument is then appended to the command line string lt dest gt editrule append argument required Then enter the name of the file or directory to copy the file s to 27 12 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Dash Statement The dash statement is used to add options to a command Many HP UX commands allow you to specify multiple options with one dash rather than using a separate dash for each option For example you can type ls Fla rather than ls F 1 a The dash statement looks like this dash string If the last
166. ers bill users pete users mary Modifying Previous Events As you use C Shell you will find that re executing a previous event with minor modifications reduces typing To modify and re execute a previous event form the new command line by using a combination of the following steps 1 Start the command with the re execution character followed by a reference to the previous event The previous event reference can be the event number location relative to the current event or text contained in the event s command line as discussed earlier 2 Optionally you can specify particular words on the chosen event s command line as discussed earlier under Reusing Command Arguments This specification is usually separated from the event reference Step 1 by a colon 3 Finally specify how you want the previous event altered by selecting from the list of modifiers that follows If you skipped Step 2 the modifier applies to the entire event If particular words were selected during Step 3 the Part Il C Shell Command History 11 5 FINAL TRIM SIZE 7 5 in x 9 0 in 11 modifier applies to those words Modifiers are always prefixed by a colon and several can be used in sequence The following list of modifiers can be used to alter or replace event arguments prior to re execution Modifier Definition s old new substitute g global h head p print q quote r root Table 11 1 Previous Event Modifiers Effect
167. erwritten ip 5 If you want to copy more than one file you must copy 27 the files to an existing directory rather than another file P For more information refer to cp 1 The second example shows the above help text as it is displayed to the user You can use the Copy_files command to copy a file to a new or existing file or to an existing directory If you copy a file to an existing file the existing file is overwritten If you want to copy more than one file you must copy the files to an existing directory rather than another file For more information refer to cp 1 27 22 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Creating Custom Softkeys This section helps you apply the concepts described in Understanding Key Shell to create your own softkeys Also refer to keysh 1 and softkeys 4 To create a custom softkey the following steps are suggested 1 Decide what you want your softkey to do If the softkey is complex you may wish to sketch a node hierarchy like that in Figure 27 1 showing the top level command and any options or sub options 2 Create a softkey file in your home directory using vi 1 or another editor 27 3 Look at the usr keysh C softkeys file for examples of commands similar to the one you want to add You can copy a similar command into your own softkey file and use it as a template 4 Create the softkey using the appropr
168. es 24 36 TMOUT 16 10 16 12 tracking aliases 18 3 trap 16 8 16 14 23 16 24 37 trapping signals 23 16 two way pipes 17 2 21 2 21 6 23 4 Index 6 type 23 6 typeset 18 4 19 5 23 13 23 15 24 38 U ulimit 23 17 24 39 umask 24 40 unalias 18 8 24 41 unset 24 42 unsetting aliases 18 8 until 21 12 24 45 utilities 15 1 V value of a parameter 16 3 19 4 vi 20 2 vi in line editing mode 20 2 VISUAL 16 10 16 12 20 2 20 4 W wait 24 43 whence 23 6 24 44 while 21 12 24 45 whitespace 15 6 who 17 1 17 3 18 1 18 3 18 8 whoami 17 3 word 15 6 Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Part IV Key Shell Korn Shell Softkey Interface Description of Key Shell Using Key Shell Visible Softkeys Invisible Softkeys Configuring Key Shell Softkey Navigation FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 25 Introducing the Key Shell This chapter introduces the Key Shell keysh a menu based softkey interface to the Korn Shell ksh It covers the following topics m Introduction to Key Shell m Who should use Key Shell a Conventions Introduction to Key Shell The Key Shell was developed by Hewlett Packard to provide a friendly user interface to the power of the Korn Shell The Key Shell provides softkey menus and online help to let you build softkey commands for such tasks as printing files viewin
169. escaped here even though it was already enclosed between single quote characters The logout Command The logout command can be used to terminate a login shell which has ignoreeof set The rehash Command The rehash command causes the shell to recompute a hash table of command locations This is necessary if you add a command to a directory in the current shell s search path and want the shell to find it Otherwise the hashing algorithm cannot locate the command because it was not present in that directory when the hash table was originally computed The repeat Command The repeat command can be used to repeat a command several times For example to make 5 copies of the file one in the file five you could do repeat 5 cat one gt gt five 14 2 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 14 The set Command The set command with no arguments shows the value of all currently defined variables For example 26 set argv O cwd usr xl1f history 15 home usr xl1f cohorts bill john mike steve mary lars ignoreeof noclobber path bin posix bin usr bin usr lib prompt E shell oin csh status 0 term hp 27 To set variables to specific values use the set command with the appropriate variable names and arguments Each of the variables shown in the preceding example were set initially by use of the set command Part Il C Shell Commands Jobs and Scripts 14
170. everal special parameters that are set automatically by the shell As mentioned above in the Return Values section holds the return value of the executed command or function Other such parameters you can use are Table 8 3 Parameters Set by the Shell Parameter Description The number of positional parameters Flags supplied to the shell on invocation or by the set command The return value sent by the previously executed command The process number of this shell The process number of the last background command Example If it became necessary to kill some processes and you especially didn t want to kill the shell you were in you could get the PID of that shell by typing echo The response to that command might be something like 1899 Part I Bourne Shell Detailed Reference 8 17 FINAL TRIM SIZE 7 5 in x 9 0 in Options for the sh Command If the sh command is used to invoke shells or shell programs you have several options available You can use the options in the following table and you can also use the options described in Table 8 1 Options to set Command Table 8 4 Options for sh Command Option Description c string Read commands from string s or if no arguments are specified Read commands from standard input Any remaining arguments become positional parameters i This specifies an interactive shell TERMINATE is ignored kill 0 does not kill an
171. evice files that do not buffer the I O Reads and writes to character devices are in raw mode Pipes A temporary file used with command pipelines When you use a pipeline the shell creates a temporary buffer to store information between the two commands This buffer is a file and is called a pipe FIFO A named pipe A FIFO First In First Out has a directory entry and allows processes to send data back and forth function key for example f1 A key on the keyboard which when pressed executes a specified computer function 9 2 Bourne Glossary Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in HP UX The computer s operating system HP UX is an HP value added version of UNIX System V input Data read by any program whether from a keyboard file or pipe internal memory Electronic data storage located in the computer for program and computer operations execution kernel The core of the HP UX operating system The kernel is the compiled code responsible for managing the computer s resources it performs such functions as allocating memory and scheduling programs for execution The kernel resides in RAM Random Access Memory message An item of information generated by the computer to inform the user of an operation or error resulting from a command nonsequential In no particular order at the same time operating system The part of the system that interacts with the user and executes the user
172. f Korn Shell 15 3 features of POSIX Shell 15 3 fg 22 3 24 16 FIFO 9 2 file 9 2 file descriptor 8 5 file name completion 17 5 17 6 file name generation 3 6 filename metacharacters 12 6 file names of shells 1 4 file name substitution 17 7 file name substitution metacharacters 17 7 files etc profile 26 3 keyshre 26 3 26 28 kshre 26 3 profile 26 1 26 3 26 28 softkeys 26 16 26 19 usr keysh C keyshre 26 3 usr keysh C softkeys 26 16 26 19 27 3 file status evaluation 13 9 file types 9 2 flags 15 6 16 10 23 9 23 10 23 13 23 14 for 6 1 21 11 24 17 foreach 14 14 foreground jobs 22 3 forking a shell 5 2 format of softkeys 27 4 formatting commands for help text 27 21 function 15 6 19 4 19 5 21 18 21 20 23 6 23 7 Index 5 FINAL TRIM SIZE 7 5 in x 9 0 in Index function 21 18 24 18 function key 9 2 function keys 26 2 functions 8 3 G global 16 4 16 7 global configuration options 26 24 gmacs 20 2 gmacs in line editing mode 20 4 goto 14 17 grave accent 5 8 group changing 8 14 grouping commands 8 2 guidelines for using Key Shell 26 4 H halting background processes 7 2 hash 8 12 help text adding to softkeys 27 20 formatting commands 27 21 hierarchy of softkey nodes 27 2 navigation through 27 3 hint text adding to softkeys 27 19 HISTFILE 16 9 16 11 20 5 history 10 7 14 2 20 5 history file 20 5 20 10 20 12 history substitution
173. f commands to be executed each time the loop is performed If the wordlist is omitted and also in then the parameter is assigned the value of each positional parameter The word list is a versatile quantity in the for construct It can be a list which you specifically type separated with blanks or it can be a shell command using grave accents which generates a list Let s look at some examples for i in l1ls Part Bourne Shell Advanced Programming 6 1 FINAL TRIM SIZE 7 5 in x 9 0 in do cp i users rhonda i echo i copied done This example will assign one file at a time from the current directory the values are generated by the ls command to the i parameter The loop s command list will copy the file to another directory then report the success of the copy You can use file name generation see File Name Generation in Chapter 3 to match files Instead of the first line of the above loop being for i in ls you could use for i in for direc in dev usr users bin lib do num ls direc we w echo num files in direc done This example lists the values to be given to direc in the loop The command list then lists each respective directory the parameters and assigns a word count wc to the num parameter Then the word count is printed out for i do sort d o i srt i done This final example will assign each positional parameter respecti
174. f the possibilities for parameter Each of these lines contains a pattern or value for parameter The brackets pattern2 refer to other values that may be valid The vertical bar represents or Finally the pattern s are followed by a close parenthesis and then by a list of commands to be executed if the patterns match An example may better illustrate case i in d r rmdir dir1 echo option d or r o echo option o echo incorrect response esac 6 4 Advanced Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Here the first positional parameter is compared to several patterns If 1 is d or r then dir1 is removed and a statement printed If 1 is 0 a statement is printed The last pattern uses the metacharacter to catch all other option possibilities and flag them as errors Remember to end each command list with and to end the entire case construct with esac Note Be aware that the order of patterns in a case is important The specific case should precede the general case For instance if you used before g there could never be any matches for the g because the would have matched them all already The dot Command Normally when you execute a shell program a subshell is created in which to execute it Therefore if you define variables in the program they are only good for as long as the program is ex
175. facility 11 1 HISTSIZE 16 9 16 11 20 5 home 13 2 HOME 16 6 16 9 16 11 16 14 home directory 4 5 4 6 HOME environment variable 4 6 HP UX commands 26 11 HP UX Reference 25 5 human interface 15 1 15 3 l identifier 15 6 if 5 10 5 15 6 9 14 14 21 8 24 19 Index 6 IFS 16 9 16 10 IFS environment variable 4 6 if then endif statements 14 14 ignoreeof 10 5 10 7 13 2 16 13 initialization of Key Shell 26 3 in line editing 20 1 20 2 20 4 input 3 2 5 12 9 3 input metacharacters 12 8 input mode 20 3 input output 8 4 input standard 17 10 inputting data 21 2 input to commands 14 18 inserting commands 5 8 integer 18 4 23 13 integer arithmetic evaluation 21 15 interactive shell 16 7 23 1 Internal Field Separators 4 6 internal memory 9 3 interrupts catching 14 19 interrupt signals 8 11 introduction to Key Shell 25 1 invisible softkeys 26 10 adding 26 19 list 26 19 invoking a shell 16 3 I O redirect 17 10 italics 15 8 J job control 22 1 job number 22 4 job number substitution 17 13 jobs 14 7 22 1 background 22 3 controlling 22 1 creating 22 1 foreground 22 3 killing 22 5 monitoring 22 1 suspending 22 2 Master Index FINAL TRIM SIZE 7 5 in x 9 0 in jobs 14 8 jobs 22 1 24 20 K kernel 2 1 9 3 15 1 KEYBEL 26 29 KEYENV 26 29 KEYESC 26 29 KEYKSH 26 29 KEYLOC 26 29 KEYPS1 26 29 keys function 26 2 KEYSH 26 26 26 2
176. ference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in exit exit Syntax 24 exit n Use this command to exit a shell The n parameter if set specifies the exit status If n is not specified the exit status is the same status as that of the most recently executed command Example if grep xxx myfile gt dev null 2 gt amp 1 gt then gt else exit gt fi This script searches myfile using grep for the string xxx If grep finds the string it returns a 0 and writes the string to dev null so the shell executes the null command If the string is not found or myfile isn t readable the shell script exits with the same return value as from grep Notice that both standard output and standard error from grep are ignored by sending them to dev null If the third line instead read gt else exit 15 the shell script would exit with a value of 15 Part Ill POSIX and Korn Shell Command Reference 24 13 FINAL TRIM SIZE 7 5 in x 9 0 in 24 export Syntax export name Las This command marks name parameters to be passed to the environment for use by other commands and subshells The export command by itself lists all currently exported values Example PSi hello export PS1 In this example the shell prompt is set to the string hello followed by a space character which causes the same string to be used by subshells For another example in y
177. file diskusage for storage This operation can take some time To restart suspended processes 22 use the fg or bg commands as explained in the next section du sort gt diskusage crRL 1 Stopped du sort gt diskusage Putting Jobs in Background Foreground Fortunately there is a way to free up your terminal and at the same time still run long processes such as du You place the process in the background A background process is one that runs invisibly to you at the same time a different process runs on your screen visible to you The process visible to you is running in the foreground The shell takes over the command line and places it in the background when you follow the line with an amp metacharacter For example if you type du sort gt diskusage amp 1 6100 the second line is what the system returned a job number and a process number If the set o monitor option is on type set o monitor at the terminal to enable a job sends a message to the terminal upon completion of the form 1 Done du sort gt diskusage amp identifying the job by its number and showing that it has completed Done For details see Chapter 23 Part Ill POSIX and Korn Shell Controlling Jobs 22 3 FINAL TRIM SIZE 7 5 in x 9 0 in 22 Two commands enable you to manipulate jobs between background and foreground bg and fg bg places a job in background fg pulls a background job into foregrou
178. file that contains the code for the POSIX Shell Table 1 2 lists both the file name that displays for each shell and the default system prompt Table 1 2 Shell File Names and Default Prompts Shell File Name Prompt Bourne bin sh POSIX bin posix sh Korn bin ksh Key usr bin keysh C bin csh Restricted Bourne bin rsh Restricted Korn bin rksh Introduction to Shells FINAL TRIM SIZE 7 5 in x 9 0 in Temporarily Changing Your Shell Unless you are in a restricted shell you can temporarily change your shell by using this command shell_name where shell_name is the name of the shell for example bin sh or oin ksh Temporarily changing your shell lets you experiment in other shells By typing the name of the shell you want to run you invoke enter that shell and the correct prompt is displayed After experimenting in the new shell return to your original shell by typing either exit or pressing CTRL D The following example begins in the Bourne Shell enters the Korn Shell and returns to the Bourne Shell bin ksh Enter Korn Shell ps Execute the ps command PID TTY TIME COMMAND 6009 tty01 0 00 ksh Notice that both the Korn Shell and 5784 tty01 0 00 sh Bourne Shell processes are running 6010 tty01 0 00 ps exit Exit Korn Shell Bourne Shell returns Permanently Changing Your Shell To permanently change your login shell the default shell you get when you log in
179. finition 27 3 deleting 26 23 disabled 27 3 display 26 2 editrules 27 8 27 9 enabled 27 3 error messages 26 5 Index 12 format 27 4 function keys 26 2 invisible 26 10 26 19 labels 26 15 menu 25 3 26 2 moving 26 23 names 26 15 navigation 27 3 node hierarchy 27 2 online help 25 3 26 6 27 21 options 26 4 26 9 26 10 parameter 26 4 27 4 selecting 26 4 string 26 4 27 4 visible 26 9 26 18 softkeys file 26 16 26 19 sort 17 1 18 1 18 3 source 14 4 spawns 16 1 special character 17 10 special characters 5 7 special commands shell programs 8 7 standard error 17 10 standard HP UX commands 26 11 standard input 3 2 17 10 standard output 3 2 17 10 START 16 7 starting Key Shell 26 1 startup C Shell 10 5 status 13 5 status line 25 3 26 2 changing 26 26 stderr 17 10 21 2 stdin 3 2 17 10 stdout 3 2 17 10 string manipulation 8 7 strings 8 8 string softkeys 26 4 definition 27 4 structure 2 2 stty 44 Master Index FINAL TRIM SIZE 7 5 in x 9 0 in stty sane 44 subscript 19 10 21 17 subshell 6 5 8 7 14 1 16 3 substituting aliases 12 2 substituting parameters 19 7 substitution command 19 11 file names 17 7 parameter 19 4 tilde 19 1 substitution command 5 8 substitution metacharacters 12 9 substitution of commands 12 4 substitution parameter 5 3 subtraction 8 7 21 15 suppressing special characters 5 7 suspending jobs 22 2 switch
180. first expression if neither expression is null nor 0 Otherwise it will return 0 Expr and Strings Expr can also be used in string manipulation the strings can be arithmetic expr expression expression will compare the first argument with the second argument which must be a regular expression There is a discussion of Regular Expressions in Tezt Processing User s Guide and in The Ultimate Guide to the vi and ex Text Editors The symbol is not a special character however because all patterns are anchored begin with Normally the matching operator returns the number of characters matched and 0 on failure expr length expression will return the length of the expression number of characters 8 8 Detailed Reference Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in expr substr expression expression expression will return a substring of the first expression starting at the character specified by the second expression and for the length given by the third expression For example a batman expr substr a 1 3 returns the string bat And a batman expr substr a 4 3 returns the string man Note that the second and third expressions must be numeric expr index expression expression will return the position in the first expression which contains a character found in the second expression a batman expr index a m returns the value 4 Set The set command has a variety of
181. following considerations m keysh shows the tsm session number in the status line a If you want to use the softkey session switching capability in TSM turn off keysh s visible softkeys with this command Keysh config options visibles off 26 a If you want session switching capability and also want to use the visible softkeys do one of the following a Use cTRL W to switch sessions where is the number of the session to which you want to switch Add the pre configured Switch softkey as a visible softkey with this command Keysh config softkey add switch TSM is described in detail in the Terminal Session Manager User s Guide Part IV Key Shell Getting Started With Key Shell 26 31 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in 27 Customizing the Key Shell Chapter 26 explained how to configure Key Shell and described the pre configured softkeys available This chapter explains how you can customize 27 Key Shell to suit your needs If you are a more advanced user and are familiar with HP UX the information in this chapter can help you make Key Shell even more powerful This chapter discusses the following topics m Understanding Key Shell m Adding text to softkeys a Creating custom softkeys Understanding Key Shell This section explains the background and concepts that are necessary for customizing Key Shell You can apply these concepts to create your own cu
182. g Existing Commands Creating Custom Commands Alias Substitution Alias Use Restrictions Unaliasing an Alias Command Substitution Metacharacters in C Shell Syntactic Metacharacters Filename Metacharacters Quotation Metacharacters Input Output Metacharacters Expansion Substitution Metacharacters Other Metacharacters Using Metacharacters as Normal Characters 13 Shell Variables Built In Shell Variables argv autologout cwd home Boolean ignoreeof cdpath Boolean noclobber Boolean notify path Shells FINAL TRIM SIZE 7 5 in x 9 0 in 11 1 11 2 11 3 11 3 11 3 11 4 11 5 11 8 12 1 12 1 12 2 12 2 12 3 12 3 12 4 12 5 12 5 12 6 12 7 12 8 12 9 12 9 12 10 13 1 13 1 13 1 13 2 13 2 13 2 13 2 13 2 13 3 13 4 Contents 5 prompt shell status 2 Numeric Shell Variables Numeric Expressions Arithmetic Operators Boolean Operators Assignment Operators Postfix Operators File Evaluation An Example 14 Commands Jobs and Scripts Csh Commands The alias Command The echo Command The history Command The logout Command The rehash Command The repeat Command The set Command The setenv Command The source Command The time Command The unalias Command The unset Command The unsetenv Command Jobs C Shell Scripts Loe When Not to Use a Script Running a Script Script Execution Shell Script Expressions Shell Script Control Structures
183. g files and listing the contents of directories These softkey commands which resemble normal English are automatically translated into HP UX syntax before being executed Part IV Key Shell Introducing the Key Shell 25 1 FINAL TRIM SIZE 7 5 in x 9 0 in 25 25 The Key Shell gives you all the capabilities of the Korn Shell including the following a Command history buffer and history substitution a Extended in line command editing a File name completion m Fast response time a Command aliasing mechanism m Bourne Shell programming environment m Integer arithmetic evaluation a Tilde substitution a Job control features m Arrays For more information on the Korn Shell refer to the part in this manual titled Korn Shell ksh In addition to the above Korn Shell capabilities Key Shell provides the following features listed in Table 25 1 which extend Korn Shell and make it easier to use 25 2 Introducing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 25 1 Key Shell Features Feature Description Flexible user interface You can enter HP UX commands by using the softkey menus or by typing on the command line Online help You can get online help for all softkey commands and their options plus general help on shell topics and keysh s features Softkey menus The top level softkey menu displays softkey commands Sub menus list option
184. g in vi VISUAL vi export VISUAL If VISUAL is assigned a string that ends in vi gmacs or emacs then the corresponding editor mode is enabled 20 2 Command lines and Command History Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Finally you can set and export EDITOR in your profile or kshrc EDITOR vi export EDITOR 20 Now if VISUAL is not set and EDITOR is assigned a string containing vi gmacs or emacs then the corresponding editor mode is enabled Performing In line Edits Now you are ready to perform in line editing Enabling an editor mode places you into the editor s command mode although when typing it does not appear anything has changed This allows you to continue typing and executing command lines as before It also allows you to type Esc and enter input mode Once you are in input mode you can edit the specified line using most vi commands and then re execute it by typing Return For example suppose you type echo surprris Then before you press the Return press ESC Now you can move on the line using Back space not 4 to the point where you made your mistake Then you execute the vi delete command x to remove the extra r and the append command A to add the letter e to the end of the line echo surprris ESc Back space Back space WAC ESC Return The new line and output looks like this echo surprise surprise For a complete listin
185. g of all the vi commands usable within the POSIX and Korn Shell vi mode see the sh posix 1 and ksh 1 manual pages in the HP UX Reference Part Ill POSIX and Korn Shell Command lines and Command History 20 3 FINAL TRIM SIZE 7 5 in x 9 0 in 20 Using emacs and gmacs Line Edit Mode The other editors implemented for in line editing are emacs and gmacs The only difference between these two editor modes is the function of the CTRL t command which transposes characters With these editors there is no command mode you are always in input mode To use emacs or gmacs commands you hold the CTRL key down while pressing a character key or press Esc followed by a character key Enabling emacs Line Edit Mode Again there are different ways to enable emacs or gmacs mode One is to type set o emacs or set o gmacs The other is to set either VISUAL or EDITOR as described in the previous vi section Performing In line Edits Now you are ready to perform in line editing with emacs As you know enabling an editor mode places you into the editor s command mode Although to you it does not appear anything has changed as you continue typing in and executing command lines For example suppose you type echo surrpri Before you press the Return press four CTRL b s This moves you left on the line to the point where you made your first mistake Then it is a simple matter of executing the CTRL a or delete co
186. he kind of work you are doing Table 1 1 Comparison of Shell Features Features Description Bourne POSIX C Korn Key Command A feature allowing commands No Yes Yes history to be stored in a buffer then modified and reused Line The ability to modify the No Yes No editing current or previous command lines with a text editor File name The ability to automatically No Yes Yes completion finish typing file names in command lines alias A feature allowing users to No Yes Yes command rename commands automatically include command options or abbreviate long command lines Restricted A security feature providing a Yes Yes No shells controlled environment with limited capabilities Job Tools for tracking and No Yes Yes control accessing processes that run in the background See Shells User s Guide Introduction to Shells 1 3 FINAL TRIM SIZE 7 5 in x 9 0 in Changing Shells Determining Your Login Shell Your system may already be configured with the shell you want to use You can display the file name of the shell you entered when you logged in by typing echo SHELL The echo command displays the contents or value of a variable named SHELL The SHELL variable contains the name of the file that contains the shell program that you are running The system responds to your echo SHELL command with something like the following bin posix sh In this case it is bin posix sh the
187. hell Using echo The echo command prints its expanded arguments to stdout The arguments are separated by spaces echo arg The echo command will do parameter expansions on unquoted arguments and on arguments in double quotes It will not do expansion on arguments in single quotes var This is var echo var This is var echo The value of var is var The value of var is This is var echo var is var var is var 21 4 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in You can also prompt a user from a script using the echo command and the c line feed escape character The escape character suppresses the linefeed and leaves the cursor after the colon and blank waiting for input Using this idea type 21 echo Enter your user name c read user echo User is user gt Enter your user name Stefan User is Stefan Certain characters can be used for formatting echoed strings These escape sequences are listed in Table 21 1 Table 21 1 echo Formatting Escape Sequences Escape Character Results b backspace c print line without appending a new line f form feed n new line r carriage return t tab v vertical tab backslash Part Ill POSIX and Korn Shell Basic Shell Programming 21 5 FINAL TRIM SIZE 7 5 in x 9 0 in 21 Using print Korn Shell provides a unique output mechanism the other shells do not the print comma
188. hell checks to see if the characters match a user s name in the etc passwd file If they do then the characters sequence is replaced by that user s login path Part Ill POSIX and Korn Shell Substitution Capabilities 19 1 FINAL TRIM SIZE 7 5 in x 9 0 in These tilde sequences are demonstrated in the following example echo HOME HOME users mary echo users mary echo PWD PWD users mary tmp ls x users mary tmp x_filel users mary tmp x_file2 echo 0LDPWD users mary mail ls f users mary mail from mike user mary mail from nick ls nick share bitmaps formats templates tools ls nick share bitmaps logo1 logo2 screendump In the first three applications of the tilde the value of the respective variables were first listed with echo Then the relevant tilde approaches were used to get similar output In the last application example Nick s files were accessed to locate a screen dump in his shared source directory share All these directory changes assume the new directories exist or the shell will send errors such as ksh users michael test bad directory 19 2 Substitution Capabilities Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Tildes can be put in aliases pwd users mary 19 alias cdn cd bin cdn pwd users mary bin In this example when cdn is executed it places you in the bin directory in your HOME direct
189. hell variables set f echo x y set f In this example you echo x y without expanding it against all the filenames in the current directory This is a result of the f option which disables file name substitution Using the turns the previously set f option off set o vi This enables vi mode history editing set is also used to set the arguments of an array set third first second echo 1 2 3 third first second Part Ill POSIX and Korn Shell Command Reference 24 31 FINAL TRIM SIZE 7 5 in x 9 0 in 24 shift Syntax shift n The shift command moves the contents of positional parameters 1 2 3 etc left one position such that 1 now contains the former value of 2 and 2 contains the former value of 3 etc Example yflag 0 zopt for arg in 0 do if x arg x y then yflag 1 shift else zopt 2 shift 2 fi done In this shell script yflag is initialized to 0 and zopt to the null string It checks all the parameters passed to the script If any one of them matches y yflag is set to 1 Using x arg avoids asking test which is invoked by the brackets to interpret y as an option If any shell argument doesn t match y it saves the next argument in zopt Using quotes preserves any whitespace embedded in 2 Also note the shifting of arguments such that 2 has the correct value when it is needed is evaluated only once before the first shift take
190. hen echo file gt break gt fi gt done This script checks the list of files x y z none for executable files and prints the first executable it encounters If none are executable file is left set to to none but it is not printed Part Ill POSIX and Korn Shell Command Reference 24 5 FINAL TRIM SIZE 7 5 in x 9 0 in 24 case Syntax case string in patternt pattern2 command list1 pattern pattern command list2 esac The case statement allows you to easily check several conditions and then process a command_line if that condition evaluates to true The first line receives a string which is checked against each of the patterns to see if it matches If the pattern matches the command_line directly following is executed Example case i in gt d r rmdir dirt echo directory removed gt o echo option o gt echo not a valid option gt esac the case statement first checks i against each option for a match If it matches d or r the directory is removed the specifies logical or If it matches o or all others an appropriate response is printed If the string does not begin with a no action is taken 24 6 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in cd cd Syntax cd 24 cd path cd old new Change directory from your current or old directory to your new dire
191. iate attributes and editrules as described in the previous section titled Understanding Key Shell Also add any text or online help as explained in the previous section titled Adding Text to Softkeys 5 Add the softkey to the list of softkeys recognized by keysh as explained in the section in Chapter 26 titled Adding Moving and Deleting Softkeys Backup Softkeys You can also use the above steps to create backup softkeys Backup softkeys are the softkeys that Key Shell can display when it cannot display its own softkeys for example when the vi editor is running Backup softkeys program the function keys to provide the static softkey control that you may have used before Key Shell does not contain pre configured backup softkeys If you wish to use backup softkeys you must create them For more information on backup softkeys refer to keysh 1 and softkeys 4 and to the online help for Keysh config options backups Part IV Key Shell Customizing the Key Shell 27 23 FINAL TRIM SIZE 7 5 in x 9 0 in 27 Examples The following example shows the definition for a custom cd 1 command Frequently used directories are added as options to the cd command Note that these options have the attribute disable all because they are mutually exclusive you can move to only one directory at a time softkey cd editrule append cd softkey keysh srce disable all editrule append keysh src softke
192. ilename Z If filename empty zero bytes long Part Il C Shell Shell Variables 13 9 FINAL TRIM SIZE 7 5 in x 9 0 in 13 An Example The following example evaluates a list of filenames and returns their status If the filename is a directory the number of lines in it is also reported bin csh This script finds directories and lists the number of files in them and their word count foreach dir argv set num 0 if d dir then echo kk dir is a directory set lsfile ls dir echo number of file in dir is lsfile foreach file lsfile set string wc 1 dir file sum string 1 end echo total number of lines in dir directory is sum else echo gt dir is not a directory endif end Now execute the script called find_dir 45 find_dir src find_dir xxxkk src is a directory number of files in src is 5 total number of lines in src directory is 3948 gt find_dir is not a directory 46 13 10 Shell Variables Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 14 14 Commands Jobs and Scripts Csh Commands C Shell supports several built in commands commands that are normally executed within the current shell If you invoke a command that is not a built in C Shell command a subshell is created spawned to handle its execution The alias Command The alias command is used to assign new aliases and to show which ali
193. ime this includes login time the POSIX or Korn Shell is invoked it looks for the file referenced by the following shell variable and executes it if it exists ENV When you invoke the shell it looks for a shell variable called ENV which is usually set in your profile ENV is evaluated and if it is set to an existing file that file is executed By convention ENV is usually set to kshre but may be set to any file name These files provide the means for customizing the shell environment to fit your needs Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 5 FINAL TRIM SIZE 7 5 in x 9 0 in Setting up profile The shell script profile sets your environment by defining commands variables and parameters at login These values if the variables are exported 16 are global and available to subshells and subprocesses Here is an example profile file PATH bin posix usr bin usr lib bin users mary bin MAIL usr mail mary HOME users mary EDITOR usr bin vi ENV START E _ 1 _ 0 _ _ i J START kshre TERM hp2392 export ENV START EDITOR TERM PATH MAIL HOME stty sane susp Z if mail e then echo You have mail fi PSt u Each line of the example profile file except the if statement and the stty command shows a POSIX or Korn Shell variable m PATH defines the search path for the shell to look up commands executable programs or utilities in the s
194. in 14 For example the expression primitive r filename tells whether the file filename exists and is readable The expression is TRUE if filename exists Other primitives test for read write and execute access to the file whether it is a directory or ordinary file and test for non zero length See test 1 in the HP UX Reference for specifications of these primitives You can determine whether a command terminated normally by enclosing it in braces command This notation returns a one 1 if the command terminated normally with exit status 0 or a zero 0 if the command terminated abnormally or with a non zero exit status If more detailed information about the execution status of a command is required the command can be executed and the system variable status examined in the next command Remember however that status is set by every command so it is very transient As an example using the normal termination condition consider the following command line if date then echo OK endif or similarly the shell script bin csh if date then prints the date echo OK prints OK endif For a complete list of expression components available for shell scripts see csh 1 in the HP UX Reference Shell Script Control Structures Control structures allowed by C Shell are similar to those in the C programming language Part Il C Shell Commands Jobs and Scripts 14 13 FINAL TRIM SIZE 7
195. in 27 Cat Softkey Example This example shows the complete softkey definition for the invisible softkey cat which lets you concatenate and display files softkey cat editrule append cat option visible enable all editrule dash v option show_tabs enable all disabled editrule dash t option show_newlines disabled editrule dash e option untbuffered editrule dash u option ignore_errors editrule dash s string lt files gt command disable 1 editrule append argument required Enter the name of the file s to concatenate 27 18 Customizing the Key Shell When you type cat keysh appends cat to the beginning of the HP UX command line If you select the visible option keysh appends a v to the command line All other options are enabled in particular the options that can only be used to modify the visible option If you select the Show tabs option keysh appends a t to the command line and keeps all the other options enabled This option is initially disabled but is enabled by selecting the visible option If you select the Show_newlines option keysh appends a e to the command line This option is initially disabled but is enabled by selecting the visible option If you select the unbuffered option keysh appends a u to the command line If you select the ignore_errors option keysh appends a s to the command line The requ
196. inal default configuration select Keysh config restart default Any changes you have made to keyshrce will be lost Undoing Configuration Changes If you want to undo the configuration changes you made select Keysh config undo This command undoes all configuration changes made since keysh was last invoked or since the last Keysh config undo command It then rewrites your keyshrc file to reflect the undone changes Selecting Keysh config undo a second time will restore your configuration changes Part IV Key Shell Getting Started With Key Shell 26 27 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Setting Shell Variables You can set any of the shell variables listed in Table 26 7 However the default values will normally be sufficient For more information refer to the section titled Setting Environment and Shell Variables in the chapter titled Starting and Stopping the Shell in the The Korn Shell ksh part of this manual You can set shell variables in either of two ways a Temporarily on the command line For example to force keysh to simulate softkeys rather than using the built in labels type KEYSIM true Return Use the unset command to unset a variable For example to return keysh to using the built in labels type unset KEYSIM Return m Permanently in your profile or keyshrc file For example to make the phrase Hi there a permanent part of your status line add the line below to
197. ing 20 2 20 4 gmacs 20 4 input 20 3 20 4 vi 20 2 modifying event arguments 11 6 modifying previous events 11 5 modularization 21 18 monitoring jobs 22 1 more 17 3 moving softkeys 26 23 multiplication 8 7 21 15 N n 4 3 5 7 name 15 6 named parameters 19 4 19 5 names for softkeys 26 15 navigation through softkeys 27 3 network special files 9 2 newgrp command 8 14 noclobber 10 7 13 2 nodes attributes 27 6 components of 27 3 format of 27 4 hierarchy 27 2 Master Index FINAL TRIM SIZE 7 5 in x 9 0 in navigation through 27 3 softkey 27 2 nonsequential 9 3 nonsequential processing 3 2 nonstandard functions aliases 12 1 not equal 21 15 notify 13 3 number job 22 1 process 16 1 number of positional parameters 5 4 numeric shell variables 13 6 o OLDPWD 16 9 16 12 online help 25 3 adding to softkeys 27 20 formatting commands 27 21 topics 26 6 using 26 6 operating system 2 1 9 3 operators arithmetic 13 6 operators assignment 13 7 operators boolean 13 7 operators logical 13 7 operators postfix 13 8 optional pieces in a pipe 7 2 options 15 6 16 10 23 9 23 10 23 11 23 13 23 14 global configuration 26 24 softkey 26 4 26 9 26 10 status line 26 26 options for set 8 10 options for sh command 8 18 options for shell commands 3 1 output 3 2 9 3 output metacharacters 12 8 output standard 17 10 outputting data 21 2 21 4 21 6 Master I
198. ing Precedence Order Precedence Order for Korn and POSIX Command Words Operator Decreasing Precedence Order Key Shell Features Using the Online Help Editing Keys Visible Softkey Commands Invisible Softkey Commands Global Options Status Line Indicators Contents 14 FINAL TRIM SIZE 7 5 in x 9 0 in 1 3 1 4 3 3 3 7 4 6 5 13 8 10 8 12 8 17 8 18 10 7 10 9 11 6 13 9 16 10 17 4 17 8 17 9 17 11 21 5 21 15 23 8 24 23 25 3 26 7 26 13 26 18 26 20 26 25 26 26 Shells 26 7 Key Shell Variables 2 2 ee ee ee 26 29 27 1 Softkey Attributes 2 0 20 2 2 27 7 27 2 Simple Expressions 1 ee ee ee ee eee 27 10 27 3 Combining Expressions 27 11 27 4 Assigning Values 2 ee ee ee ee 27 12 27 5 Formatting Commands 2 2 2 2 2 27 21 Shells Contents 15 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Introduction to Shells What are Shells For purposes of this User s Guide a shell is the interface between HP UX and you the user The shell interprets the text you type and the keys you press in order to direct the HP UX operating system to take an appropriate action A shell can also serve as a programming language What is Bourne Shell Bourne Shell is the oldest shell It was written by Stephen Bourne at Bell Laboratories The Bourne Shell has been the default shell for HP UX users and has bee
199. interactive shell and INTERRUPT is caught and ignored so that wait is interruptible r Make the shell restricted see below Restricted Bourne Shell Making a shell restricted or rsh causes the following actions to be disallowed m changing the directory cd m setting the value of PATH m specifying path or command names containing m redirecting output gt and gt gt The restricted shell is useful when you wish users to have limited access to the system Make sure the directories in which the restricted users are placed do not give them access to subdirectories in which they may do damage Also make sure they do not have commands available to them such as chsh and csh that let them escape the restricted shell See sh 1 about provisions to ensure this 8 18 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Bourne Glossary background process A process that has been scheduled nonsequentially background processes are generally transparent to the user control key CCTRL_ Used with other keys in the same manner as the Shift key to generate special characters cursor A visual position indicator which moves with characters entered with the keyboard or with cursor movement keys a C 0 CO device file The file associated with an I O device Device files are read and written just like ordinary files but requests to read or write result in activ
200. into groups of four Note that there are four banks of available softkeys in the top level menu Select More several times to familiarize yourself with the softkeys on each bank 26 2 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Key Shell Initialization This section describes what happens when you start Key Shell For information on the login program and on setting up your profile and kshrc files refer to the chapter titled Starting and Stopping the Shell in the The Korn Shell ksh part of this manual When you start keysh it performs the following tasks m Customizes your shell environment by executing these files etc profile profile and the file indicated by the ENV variable in profile typically kshrc 26 keysh then resets the initial value of the PS1 PS2 and PS3 shell variables Do not subsequently change these variables from the command line Instead you can use the KEYSH variable to display status information described in the section titled Setting Shell Variables m Determines characteristics of your terminal as specified by the TERM shell variable Also checks LINES and COLUMNS if set m Configures itself based on your local keyshrc file If this file does not exist usr keysh C keyshrc is used instead The keyshrc file contains configuration information for the following o Visible softkeys and their labels co key
201. ired line then prompts you for the required information the file name s to concatenate Since multiple file names are allowed this node is not disabled after it is selected However all options preceding this one are disabled keysh then appends the argument s to the command line Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Adding Text to Softkeys When you create a softkey command you can add your own text to it to prompt the user for information or to provide help in using your command This text can be any of the following m Required text is used to inform users that they must select an option or supply information before proceeding Hint text is used to prompt users for optional information Hints can only be used for string type softkey nodes 27 m Help text is used to explain custom softkeys and options The following sections explain each of these types of text Adding Required and Hint Text To add required or hint text to a softkey follow these guidelines m Start the text with the keyword required or hint m Enclose the text in quotes m Do not make the text longer than 79 characters m Use the backslash to escape special characters within the text such as quotation marks The following example of required text is from the Copy files softkey Because the Copy files command does not make sense unless you specify the name of the file s to copy the file name is required keysh will not c
202. is to reference its position in the history buffer relative to the current event For example 8 4 mail jd lt memo 9 executes event four 8 4 4 in this case sending a memo to jd again Referencing by Event Text You can re execute an event by entering the first few characters of that event s command line If you have previously executed history you can see what the current history buffer contains by using 9 th The history substitution facility searches backward through the buffer until it finds an event whose command line begins with the letter h When it finds the event with the history command line it re executes it producing 9 th 1 1s als 2 cat junk 3 pr memo lp 4 mail jd lt memo Part Il C Shell Command History 11 3 FINAL TRIM SIZE 7 5 in x 9 0 in 11 5 vi cshre 6 history 7 cat junk 8 mail jd lt memo 9 history 10 Reusing Command Arguments The history substitution facility enables you to use parts of previous commands as building blocks of new commands Each command argument in a command event is numbered To reference a command argument specify the event with one of the methods described previously in Re executing Events then use a colon followed by the argument s position number The first argument usually the command is argument number zero 0 The second argument is argument number one 1 etc The last argument is given the special refere
203. isible softkeys 26 10 Key Shell 26 4 online help 26 6 visible softkeys 26 9 ust keysh C keyshre file 26 3 Part IV Key Shell usr keysh C softkeys file 26 16 26 19 27 3 Vv variables assigning values to 27 12 visible softkeys 26 9 adding 26 16 list 26 18 Ww word list 27 9 Index Index 5 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Master Index FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Index Index Special characters 16 10 17 9 5 13 16 10 17 13 19 7 19 10 21 2 19 7 5 2 5 3 16 3 17 9 19 7 C 19 11 19 10 19 10 16 2 16 3 17 13 19 7 22 4 hh 19 7 22 4 t 22 4 22 4 amp 17 3 22 3 amp amp 8 1 17 3 17 9 19 11 21 18 3 6 17 7 19 10 16 10 65 lt 3 3 3 5 17 10 lt lt 17 10 gt 3 3 3 5 17 10 gt gt 3 3 3 5 17 10 3 6 16 10 17 7 19 7 19 10 CJ 21 7 22 1 5 7 17 9 17 9 19 11 3 19 7 21 1 21 18 15 6 17 1 18 1 l amp 17 2 21 2 21 6 23 4 Master Index FINAL TRIM SIZE A abbreviating commands 18 1 accessing arrays 21 17 accessing history file 20 5 20 10 20 12 accessing variables 14 11 accumulated user and system times 8 15 adding help text to softkeys 27 20 hint text to softkeys 27 19 invisible softkeys 26 19 required text to softkeys 27 19 text to sof
204. it is the same as the exit status of the process requested by the last process_id operand in the wait command Part Ill POSIX and Korn Shell Command Reference 24 43 FINAL TRIM SIZE 7 5 in x 9 0 in 24 24 whence Syntax For Korn Shell only whence v name This command limited to the POSIX and Korn Shell indicates for each name how it would be interpreted if used as a command name If the v option is set the results are more verbose Example whence history This example discovers that history is actually an exported alias for fc 1 See Chapter 23 for a detailed explanation 24 44 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in while until while until Syntax while kisti 24 do list done This loop cycles through list and executes all the items in list2 if list1 evaluates to true Once list evaluates false the loop is exited Example x 0 while x 10 gt do gt let x x 1 echo x done gt gt 1 2 3 4 5 6 7 8 9 10 This loop initializes the variable x increments and prints the value until it reaches 10 then exits the loop The until loop has the same syntax as while However it executes until a non zero is returned and always executes the loop at least once Part Ill POSIX and Korn Shell Command Reference 24 45 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Index Special
205. itor nlr first last fc e old new command In the first line part of the syntax indicates listing the history file If 1 first and last are indicated the commands from the first string or number to the last string or number are listed This example prints the lines 20 thru 23 fc 1 20 23 20 ll a 21 more file 22 ps 23 pwd If followed by a number as in fc 1 23 then command lines from 23 on are displayed fc 1 23 23 pwd 24 lsf 25 echo surprise Part Ill POSIX and Korn Shell Command lines and Command History 20 7 FINAL TRIM SIZE 7 5 in x 9 0 in 20 Two other options are available r which reverses the order of the commands and n which suppresses listing of the command numbers For example fc e vi n 24 25 With this command line you are placed in the vi editor with the commands 24 thru 25 without command numbers Edit the lines When you write and exit the file the commands in the file are immediately executed as shown here lsf echo surprise wq tmp sh1111 12 2 lines 20 characters ll a echo surprise adv filet file2 surprise If you do not specify a 1 or an editor name with e the value of the shell parameter FCEDIT is used if it is set otherwise the shell returns an error 20 8 Command lines and Command History Part Ili POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The 1 option used with no other arguments displays the
206. l for more on command grouping see Command Grouping in Chapter 8 Therefore the two commands pr and sort are run nonsequentially So at the same time the pdir file is formatted and sent to the printer and the local file is sorted Finally the cat command is run which appends the local file to the pdir file File Name Generation A helpful way to reduce typing is to use patterns to match file names If you are in a directory with a file programming you can see a listing with either ls programming or you can use a pattern to match ls p where will match any character or string of characters If you have another file beginning with p it too will be listed Table 3 2 shows the file generation symbols you can use 3 6 Shell Commands Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 3 2 File Generation Symbols Symbol Description Matches any string of characters including the null string Matches any single character C Matches any one of the characters enclosed in the brackets A pair of characters separated by a minus will match any character between the pair lexically La z cubit ca will match a file which begins with any character a through z lower case followed by any single character followed by the string cubit followed by any number of characters and which ends in c or a Part I Bourne Shell Shell Commands 3 7
207. l Getting Started With Key Shell 26 17 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Table 26 3 shows the visible softkey commands that are configured in keysh Table 26 3 Visible Softkey Commands Softkey HP UX Function Equivalent Mail mailx Processes electronic mail interactively Change dir cd Changes the current directory List files ls Lists the contents of a directory Edit file vi Edits files on a screen oriented display Display files more Displays the contents of a file one screen at a time Print files pr 1p Formats a file and sends it to the line printer Search lines grep Searches for lines matching a pattern Sort lines sort Sorts the lines of a file Find files find Locates files within a directory Copy files cp Copies file to another location Move files mv Moves or renames a file Set file attribs chmod Changes permissions owner or group of a file chown chgrp Remove files rm Deletes a file Remove dirs rmdir Deletes a directory Create dirs mkdir Creates a new directory Shell archive shar Bundles one or more files into a shell archive package for mailing or moving Print status lpstat Shows current status of all printers 26 18 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 26 3 Visible Softkey Commands continued Softkey HP UX Function Equivalent Cancel print cancel Cancels a print request Process info ps Shows status of active pr
208. l command Part Il C Shell Command History 11 9 FINAL TRIM SIZE 7 5 in x 9 0 in 11 rwxr xr x 1 jerry 1751 Feb 29 09 00 a out rwxr xr x 1 jerry 1751 Feb 29 09 01 bug 29 bug hello 30 pq n s g g c pq n bug c pq Command not found 31 s pq pr Correct spelling in last event from pq pr n bug c to pr 1 main 2 3 printf hello n 4 32 lp Execute last executable event pr n bug c lp and pipe to line printer spooler 33 11 10 Command History Part Il FINAL TRIM SIZE 7 5 in x 9 0 in C Shell 12 Aliases Command Substitution Metacharacters Aliases C Shell provides an alias facility so you can customize commands With aliasing you can define new commands or make standard commands perform nonstandard functions The alias facility is similar to a macro facility when an alias is detected it is replaced by the alias definition To list existing aliases enter alias without arguments For example 41 alias cd cd ls h history print pr lp W who echo You are who am i dir ls als You can create the above aliases interactively from the terminal keyboard or by placing alias commands in a shell script Aliasing Existing Commands You can alias HP UX commands so that they perform nonstandard functions Suppose you like to get a directory listing whenever you change directories Do this by aliasing cd in the following w
209. last 16 commands fc 1 21 more file 20 22 ps 23 pwd 24 lsf 33 Isf users guest 34 pwd 35 x filel 36 echo x moved to new directory In this next example the second syntax line replaces an old string with a new string in the command Here command can be either a command name or line number The shell makes this substitution possible by building into fc certain simple editing capabilities that are used when the e editor that is specified is a dash Using that editor surprise is replaced by neat and echoed to the screen echo surprise surprise fc e surprise neat echo echo neat neat Part Ill POSIX and Korn Shell Command lines and Command History 20 9 FINAL TRIM SIZE 7 5 in x 9 0 in 20 An fc e without any arguments displays and executes the last item in the history file which is also the most recent command executed If you type alias for a list of aliases you see that r is set to fc e such that executing r executes the last command Since the last command just happens to be fc e this re executes the last command echo Accessing the History File From vi Mode There are other sequences that can be executed from vi mode such as E50 0 0 and Ee count The following sequences do the following or Esc C Recalls previous command and steps backward Press or then k or to step through and Moves forward to next command Once you type Esc k
210. le 5 Basic Shell Programming Parameters Using Parameters in Shell Programs Parameter Substitution Positional Parameters Shift Echo Quoting The Backslash The Double Quote The Single Quote Command Substitution Conditions The if Statement Test Read Exit Comments Example Moving Files Discussion of Example Moving Files 1 test if there are any arguments ask if file is to be moved to directory or file 2 3 test if x is a directory if not leave script 4 test if it is a file 5 response is not dorf Contents 2 FINAL TRIM SIZE 7 5 in x 9 0 in 3 5 3 6 3 6 4 1 4 1 4 2 4 2 4 3 4 5 5 2 5 3 5 3 5 4 5 5 5 7 5 7 5 7 5 8 5 8 5 8 5 10 5 11 5 12 5 13 5 13 5 14 5 16 5 16 5 16 5 16 5 16 5 16 Shells 6 Shells Advanced Programming Looping 6 1 For 6 1 While 6 3 Until 6 3 Case Loe ee 6 4 The dot Command 6 5 The eval Command 6 6 Using Shell Expansions 6 7 Helpful Tips 6 8 Example Groupcopy 6 9 Discussion of Example Groupcopy 6 13 1 test to make sure the directory parameter is s included 6 13 2 look for options a 6 13 3 test if parameter is a directory a 6 13 4 begin main loop Lo 6 13 5 parameter is not a directory 6 14 Programming Tips Debugging 7 1 Creating Optional Pieces i ina a Pipe 7 2 Halting Background Processes 7 2 Detailed Reference Command Separators 8 1 The amp amp Separator 8 1 The
211. lists all files starting with a p and having a prog a anywhere in the middle or at the end prog c prog a prz 2 1s a z rog co Matches any of the characters enclosed in the arog o brackets A pair of characters separated by a crog c minus matches any one character in the range prog a specified by the two letters in the alphabet In prog c this example 1s lists any file starting with a prog o lower case letter of the alphabet followed by zrog c rog and ending with either c or o In the 1s a z rog o second 1s the comma performs the same way arog o as the co does without a comma zrog o Note that neither nor match a leading period or a Also for NLS there are additional constructs available See regexp 5 17 8 Shell Grammar Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Quoting Each of the metacharacters discussed above can be quoted or protected to make it stand for itself and not be interpreted by the shell as a special character Table 17 3 Quoting Metacharacters lists and gives examples 17 using these metacharacters Table 17 3 Quoting Metacharacters Meta Example Description character 1s prog The backslash cancels the special meaning of prog echo PWD PWD echo PWD PWD echo PWD users mary echo PWD PWD the metacharacter that follows it Note that the backslash is not
212. ll script which calls itself Expr The expr command is very useful for performing arithmetic operations in shell programs It also has other operations useful for string manipulation With the form expr expression expression you can add or subtract integers a 15 expr a 5 will return the string 20 To modify variables you can use a similar format to a expr a 1 using command substitution grave accents to place the new value in the variable a The symbols for multiplication division and remainder of integer valued arguments are and respectively Note the is preceded by a backslash to escape the shell s interpretation of the asterisk Part I Bourne Shell Detailed Reference 8 7 FINAL TRIM SIZE 7 5 in x 9 0 in To compare integers use the following format expr expression gt gt lt lt expression where is not equal to and the other symbols represent mathematical comparisons again note the backslash before the special characters lt and gt The function will return 0 if the comparison is successful and 1 if it is not Here is an example of how a comparison might be used if expr a lt b then echo a is less than or equal to b fi Conditions expr expression expression will return the first expression if it is neither null nor 0 Otherwise it will return the second expression expr expression amp expression will return the
213. lse command_X command_Y endif Note that only one endif is used to end the entire structure C Shell has another form of the if statement if expression command can be written if expression command If you only need to execute one command the endif statement can be omitted In the second example the non printing newline character is escaped Part Il C Shell Commands Jobs and Scripts 14 15 FINAL TRIM SIZE 7 5 in x 9 0 in 14 with the backslash to allow the command to appear below the expression This is to improve visual clarity The while Command The while structure is like that found in the C programming language For example while expression command_1 command_2 end The switch Command The switch structure is like that found in the C programming language For example switch word case strl commands breaksw case strn commands breaksw default commands 14 16 Commands Jobs and Scripts FINAL TRIM SIZE 7 5 in x 9 0 in Part Il C Shell 14 breaksw endsw Note C programmers should note that the switch command uses breaksw to exit and not break While and foreach loops allow break The goto Command C Shell allows the goto statement with labels just like C loop command_1 command_2 goto loop Part Il C Shell Commands Jobs and Scripts 14 17 FINAL TRIM SIZE 7 5 in x 9 0 in 14 Supplying Input to Commands By default com
214. m a script like in the above example you may wish to place some headers or comments in the output and place the output into a file The echo command will print titles or comments for you It works in the following manner echo string where string is a string of characters 4 2 Shell Scripts Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Modify your example script to look like echo Current date and time c date echo Users logged in n who echo nCurrent processes ps ef echo nUser disk usage du users where c causes the next line of output to be printed on the same line and n causes an extra carriage return and line feed for more detail see Echo in Chapter 5 Next you can execute the file using the redirection symbols to append the output to another file For example let s say our file is called status1 and the file we wish to place the output in is called status_file statusi gt gt status_file Each time you monitor the system you can have the output added to a file The profile File The Bourne Shell runs a script automatically when you login called profile This script sets the environment in which you work it sets up certain variables which tell the system where to look for a command what the prompt should look like where to get the mail and other variables The profile file is usually set up by the system administrator but you can customize it
215. m separated by newlines Return s the commands are executed sequentially or in the order they appear in the file The following separators allow you to control the sequence of command execution The amp amp Separator This separator is a conditional separator It will execute the next command in the command line only if the previous command executes successfully test d users rhonda tools amp amp cd users rhonda tools This command line will first test to see if users rhonda tools is a directory If it is the cd command is executed If not no further action is taken Part I Bourne Shell Detailed Reference 8 1 FINAL TRIM SIZE 7 5 in x 9 0 in The Separator The double vertical bar separator will execute the next command only if the previous command was unsuccessful test d users michael projects echo directory does not exist This command line will test to see if the directory users michael projects exists If the test fails the echo command is executed Mixing Separators Here is an example which mixes the above separators test d tools amp amp cd tools test z fn sort o fn fn amp The shell uses and amp to terminate a command sequence Thus there are two command sequences test d tools amp amp cd tools and test z fn sort o fn fn The first sequence is executed before the second because of the separator If the first test is successful the cd command is ex
216. m the output of the process spawned with two way pipes amp See Chapter 23 for two way pipes r Do not interpret the at the end of a line as line continuation s Put the input line into the history file un Read the input from file descriptor n In this script contained in the file hello_script the first line prints a prompt and waits for input read user_name What is your name echo Hello user_name and welcome to Korn Shell The read command prompts the user for a name and stores the name in the variable user_name Running the script creates this output hello_script What is your name Stefan Hello Stefan and welcome to Korn Shell When you see the question mark type in your name Stefan is typed here and underlined to indicate user input and then press Return Part Ill POSIX and Korn Shell Basic Shell Programming 21 3 FINAL TRIM SIZE 7 5 in x 9 0 in 21 The read command can read and store several values at one time read fieldi field2 junk This reads the first whitespace separated name from the input line into field the second into field2 and the rest into junk Printing Data Sometimes you may wish to output data or comments from a script on the screen such as script results and headers to describe the results There are two output mechanisms in the shell The first is the echo command used in Bourne C and POSIX Shells and the second is the print command unique to Korn S
217. mands run from shell scripts use the standard input of the shell which is running the script This is different from how other shells run under HP UX This allows C Shell shell scripts to fully participate in pipelines but extra notation is required for commands which use in line data Thus we need a metanotation for supplying in line data to commands in shell scripts For example consider this script which runs the editor to delete leading blanks from the lines in each argument file The lt space gt and the lt tab gt in the example represent the space and the tab characters deblank remove leading blanks foreach i argv ed i lt lt EOF 1 s lt space gt lt tab gt W q EOF end The notation lt lt EQF means that the standard input for the ed command is to come from the text in the shell script file up to the next line consisting of exactly EOF The fact that the EOF is enclosed in single quote characters causes the shell to not perform variable substitution on the intervening lines In general if any part of the word following the lt lt which the shell uses to terminate the text to be given to the command is quoted then these substitutions will not be performed In this case since we used the form 1 in our editor script we needed to insure that this was not variable substituted We could also have insured this by preceding the here with a that is 1 s but quoting the
218. maximum of 16 characters Many of the following sections ask you to type a softkey s name or label If you refer to a softkey by its label you must replace any blank space in the label with an underscore _ For example type Edit_file or Create_dir Part IV Key Shell Getting Started With Key Shell 26 15 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Adding Visible Softkeys The pre configured visible softkeys are listed in Table 26 3 These softkeys appear in the top level softkey menu You can also create your own visible softkeys or add any of the invisible softkeys listed in Table 26 4 and make them visible Creating your own softkeys is described in Chapter 27 To add a visible softkey follow these steps 1 Select Keysh config softkey add 2 Type the name of an invisible softkey as listed in Table 26 4 or the name of a softkey you have created 3 By default the softkey label that will appear on the menu is the same as the softkey s name To specify a label that is easier for you to remember select with label then type the label 4 By default the softkey is added from usr keysh C softkeys If you want to add softkeys from another file do either of the following a Select from file then type the name of the file containing the softkey you want to add b Select from user then type the name of the user whose HOME softkeys file contains the softkey Note that when you add a softkey the remaining softkeys
219. me if a prompt is being displayed If ignoreeof is not set you can also use CTRL D Returning to a Parent Shell If you started C Shell from another shell with ignoreeof set type exit to return to the original shell If you use CTRL D and ignoreeof is set the error message Use exit to leave csh results You will know that you have returned to the Bourne or Korn Shell because the shell prompt changes to your Bourne or Korn Shell prompt If ignoreeof is not set you can use CTRL D or exit to obtain the same result 10 4 Preparing to Use the Shell Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 10 Logging Off the System If C Shell is your default login shell and you have not set the system variable ignoreeof you can terminate C Shell and log off the system by typing exit or logout or by pressing CTRL D The system variable ignoreeof is discussed later If a file HOME logout a file named logout in your home directory exists it is executed as part of the log off process Terminating C Shell with ignoreeof Set If C Shell is your default login shell and the system variable ignoreeof is set you cannot terminate C Shell and log off the system by typing ctRL If you attempt to do so the system responds with the message Use logout to logout C Shell Startup Depending on whether it is your default login shell C Shell looks for one or all three of the following files and exec
220. mes we execute a script and then realize a mistake was made and press the key to stop the process It is possible the script created several files on the system that you would have to search for and manually delete Fortunately the trap command captures an interrupt Now you can Break let the trap command capture it and then clean up the files from within the script The syntax is trap arg signal Lee The trap waits for signals sent to the shell traps it and then executes arg After setting traps typing trap with no args lists all commands associated with signals For example temp tmp xyz trap rm f temp exit O 2 3 15 trap O rm f tmp xyz18996 exit 2 rm f tmp xyz18996 exit 3 rm f tmp xyz18996 exit 15 rm f tmp xyz18996 exit in the first line a temporary file temp is defined whose name includes xyz and the process id number The second line sets a trap to remove the file without complaining if it doesn t exist yet or if the remove fails It then exits the shell if the shell exits 0 or receives one of a certain set of signals 2 3 15 which could be given by names INT QUIT TERM After setting the trap trap with no options lists all traps The exit in the trap is necessary because otherwise the trap would be like an interrupt routine returning to execution of the script on receipt of a signal 23 16 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x
221. mine whether on not your shell is interactive type set o and look for interactive on This kshre file normally contains commands to set up the POSIX or Korn Shell s environment However if this file is exceedingly long spawning the new shell can be a long process This complicated ENV variable prevents kshre from being read when not in interactive mode Part Ill POSIX and Korn Shell Advanced Concepts 23 1 FINAL TRIM SIZE 7 5 in x 9 0 in 23 23 You can turn off the processing of the ENV file for non interactive shells with the following in your profile export ENV FILEL _ 1 _ 0 _ _ 2 i 1 export FILE HOME envfile The idea behind this scheme is to set up an array FILE whose first element is the file we want executed at startup and whose second element is null export FILE HOME envfile echo FILE O users pbm envfile echo FILE 1 We then want to set ENV to FILE 0 for interactive shells and set ENV to FILE 1 for non interactive shells To do this we need an expression that will evaluate to 0 for an interactive shell and will evaluate to 1 for a non interactive shell ENV FILELmagic_expression The flags variable is the key to forming our magic_expression If the shell is interactive the flags will contain an i The expression used as the index consists of three parts that are combined to form the final index _ 1
222. mmand grouping 8 2 command interpreter 2 1 command separators 8 1 command substitution 5 8 comments 5 13 conditional branching 6 4 conditionally executing commands 8 1 conditions 5 10 8 8 connecting programs 3 4 continue looping 6 8 control key 9 1 conventions 2 4 creating shells 5 2 creating your own parameters 5 2 cursor 9 1 customizing profile 4 5 Index 1 7 5 in x 9 0 in Index D data paths 3 2 debugging 7 1 defining functions 8 3 definitions 2 3 device file 9 1 directory structure 8 13 disk 9 1 division 8 7 do 6 1 done 6 1 dot command 6 5 double quote 5 8 driver number 9 1 E echo 4 5 5 2 5 7 5 15 echo command 4 2 edit 9 1 C 3 6 else 5 10 environment 4 3 9 2 environment variable CDPATH 4 6 HOME 4 6 IFS 4 6 MAIL 4 4 4 6 MAILCHECK 4 6 MAILPATH 4 6 PATH 4 4 4 6 PS1 4 5 46 PS2 4 6 5 1 SHACCT 4 6 SHELL 4 6 TERM 4 4 error codes 8 16 error output 3 2 esac 6 4 eval 6 6 exec 8 7 executing commands 3 4 8 1 Index 2 executing commands in shell 6 6 executing nonsequential commands 3 2 executing sequential commands 3 1 executing shell programs 4 1 execution 9 2 exit 5 13 5 15 exit a loop 6 8 exit status 5 13 export 4 4 expr 8 7 8 8 F FIFO 9 2 file 9 2 file descriptor 8 5 file name generation 3 6 file types 9 2 for 6 1 forking a shell 5 2 function key 9 2 functions
223. mmand on the extra r To move forward again use CTRL e To move the cursor to the end of the line Now simply type in the rest of the line echo surrpri CTRL OCR OCR OOORaa Note that CTRL b is in fact pressed four times rather than one 20 4 Command lines and Command History Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The new line and output looks like this echo surprise surprise There are also sequences that move you forward and backwards by words rather than letters b moves you backwards one word and ESC f moves you forward one word For a complete listing of all the emacs commands usable within the POSIX and Korn Shell emacs mode see the sh posix 1 and ksh 1 manual entries in the HP UX Reference Accessing the History File Accessing the History File allows you to access a line typed in earlier with a few key strokes easily enter an editing mode change the line and re execute it This is possible through several mechanisms provided by the POSIX and Korn Shell the fc command the vi line edit mode and the emacs and gmacs line edit mode In Chapter 16 the two shell variables HISTFILE and HISTSIZE are discussed The history file specified by HISTFILE contains the latest commands you executed at your terminal Every time you type a command at the prompt and press Return it is stored in this history file HISTSIZE specifies the maximum number of commands stored in
224. must be typed exactly as shown or text as it is displayed by the system For example findstr prog c gt prog str Note when a command or file name is a literal it is shown in computer font and not italics However if the command or filename is symbolic but not literal it is shown in italics as shown here alias new_command command_line In this case you would type in your own command_line and new_command Computer font also indicates file names HP UX commands system calls subroutines and path names In a syntax statement brackets designate optional parameters ellipses designate optional repetition of a word or parameter directly preceding them In the following example path is an optional parameter to the cd utility cd path Environment variables such as EDITOR or PATH are represented in uppercase characters an HP UX convention A keycap such as Retum designates the pressing of that key If the keycaps are connected by a hyphen press the first key down and hold it while pressing the second key For example GRO 15 8 Introducing the Shells Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in m Unless otherwise stated all references such as see the env 1 entry for more details refer to entries in the HP UX Reference If you cannot find an entry where you expect it to be use the HP UX Reference index 15 Supplementary Information Resources A valuable Korn Shell
225. n Process Ds can be displayed using the ps command see ps 1 Example sleep 20 amp kill 1235 This example executes a sleep 20 which happens to be process 1235 then sends it a SIGTERM terminate sleep 20 amp kill 9 1 This starts sleep 20 which happens to be job 1 then sends it a kill SIGKILL Part Ill POSIX and Korn Shell Command Reference 24 21 FINAL TRIM SIZE 7 5 in x 9 0 in 24 kill kill 1 kill HUP 3140 Using the 1 option with kill lists the signal names The second line sends a SIGHUP to process 3140 kill 1 9 applies to POSIX Shell only This will display the signal name corresponding to the exit status In this case KILL This is usually used with the exit status after returning from a wait command 24 22 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in let let Syntax For Korn Shell only 24 let arg This Korn Shell command allows for long integer arithmetic normally performed by the expr command Each arg is an arithmetic expression of shell parameters and operators that are evaluated by the shell Table 24 1 lists operators in decreasing order of precedence Table 24 1 Operator Decreasing Precedence Order Operator Description unary minus logical negation multiplication division remainder addition subtraction lt gt lt gt comparison equals not equals
226. n time When a background job terminates a message is sent to the terminal by the shell just before the next prompt telling you that the job is complete In the following example the du job finishes sometime during the execution of the mail command and its completion is reported just before the prompt that follows completion of the mail job du gt usage amp 1 503 mail bill How do you know when a background job is finished EOT 1 Done du gt usage 4 If the job did not terminate normally the Done message might say something else like Killed If you want the terminations of background jobs to be Part Il C Shell Commands Jobs and Scripts 14 7 FINAL TRIM SIZE 7 5 in x 9 0 in 14 reported at the time they occur possibly interrupting the output of other foreground jobs you can set the notify variable In the previous example this would mean that the Done message might have come right in the middle of the message to Bill Jobs are recorded in a table inside the shell until they terminate In this table the shell remembers the command names arguments and the process numbers of all commands in the job as well as the working directory where the job was started Each job in the table is either running in the foreground with the shell waiting for it to terminate or running in the background Only one job can be running in the foreground at one time but several jobs can run simultaneously in the background Each job i
227. n a de facto standard in the industry The Bourne Shell has neither the interactive features nor the complex programming constructs of the C and Korn shells What is C Shell C Shell is a shell developed by Bill Joy at the University of California at Berkeley The C Shell syntax resembles that of the C programming language It has powerful interactive features like command history and file name completion What is Korn Shell Korn Shell is a newer shell developed by David Korn at Bell Laboratories and is upwardly compatible with most Bourne shell features It has interactive features like C Shell but executes faster and has extended in line command editing capability Introduction to Shells 1 1 FINAL TRIM SIZE 7 5 in x 9 0 in What is POSIX Shell POSIX Shell is based on the standard defined in Portable Operating System Interface POSIX IEEE P1003 2 This standard is designed to be used by both application programmers and system administrators This standard is intended to describe language interfaces and utilities in sufficient detail so an application developer can understand the required interfaces without access to the source code of existing implementations on which they are based Most of the POSIX Shell features are similar to the Korn Shell This guide covers both shells in the same Part In addition to the common features this guide also covers the differences between the POSIX and Korn Shells and the new features i
228. n executed yet Your screen should look like that in Figure 26 4 Change_dir parent_dir cd E hpfcjdp fusers jodi Wo mail 03 45 16 PM Figure 26 4 After Selecting the Parent Dir Option Part IV Key Shell Getting Started With Key Shell 26 9 FINAL TRIM SIZE 7 5 in x 9 0 in 26 4 Look at the directory shown on the status line then press Return to execute the command The Change dir parent dir command changes your current directory to its parent the next higher directory In the above example the current directory is users jodi The parent directory and new current directory would be users Notice also that the status line has changed to reflect the new current directory Using Invisible Softkey Commands To use the invisible softkey commands type a recognized HP UX command one of those listed in Table 26 4 keysh will display the softkey options for the command Select any softkey options Then press Return to execute the command or press to see the command translated into HP UX syntax keysh notifies you if you forget to supply any required information For example to see how the invisible softkey commands work follow these steps 1 At the keysh prompt type the following Do not press Return yet cal 2 Because cal is a standard HP UX command that keysh recognizes it displays the available softkey options for the cal command 3 Select the for mo
229. n x 9 0 in 13 13 7 13 Asin x y is the compressed form of x x y As in x y is the compressed form of x x y Asin x y is the compressed form of x x y 4 Asin x f y is the compressed form of x x y As in x y is the compressed form of x x y Postfix Operators Finally as a special case and can be used as postfix operators to increment and decrement Thus the following statements give identical results i 40 i i 1 4 it 1 Note The and operators do not require a in front of the variable name Either of the following must appear alone on a line namet name The following operators do not work amp lt lt gt gt 13 8 Shell Variables Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 13 File Evaluation Expressions can also return a value based on the status of a file If the specified file expression is true the expression returns one 1 If not true then the expression returns a zero 0 It the file does not exist or is not accessible the expression returns zero 0 The syntax for a file expression is file_test filename where file_test is selected from the list in Table 13 1 Table 13 1 file_test Meanings file_test meaning d Is filename a directory e Does filename exist f Is filename a plain file o Do I own filename r Do I have read access to filename w Do I have write access to filename x Can I execute f
230. nce of the dollar sigh The second argument usually the first argument after a command word is given the special reference of the circumflex To see how this works begin with the example shown below 10 nroff man csh 1 lp amp To see what the last argument in this event is type in 11 10 amp 12 The last argument in event 10 is the ampersand amp The history mechanism extends the normal meaning of argument to include important metacharacters The argument specified by a circumflex is man To see if this is true type in 12 echo 10 7 echo man man Command not found 13 11 4 Command History Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 11 The referenced argument can be made part of another command A range of event arguments can also be specified by using a dash to separate the range endpoints For example 13 echo 10 3 echo lp amp 1 18634 18635 14 Note that the example generated a new C Shell with the event number 1 and two process IDs 18634 18635 This new shell is called a background process The output from echo is printed on the line printer by piping it to the printer spooler Jobs and job numbers are discussed later in this tutorial If you want to reuse all of the arguments of an event that follow an initial command you can use an asterisk 14 mkdir users bill users pete users mary 15 rmdir 14 rmdir us
231. nd standard output When input and output operations access the same file the results are unpredictable Part I Bourne Shell Shell Commands 3 3 FINAL TRIM SIZE 7 5 in x 9 0 in If a file you specify with a redirection symbol is not in the current directory you should use a path name to identify it The following actions are taken when the system does not locate files named with the redirection symbols m If a file specified for input with the lt symbol is not located an error message is displayed m If a file specified for output with the gt or gt gt symbol is not located it is created and used for program output Examples The following examples show how the data paths of programs commands or utilities can be modified with the redirection symbols CHItest lt datal Runs the program CHItest using the file data1 as input date gt gt syslog Adds the current time and date to the end of the file syslog Pipes Two or more programs or commands can be connected so the output of one program is used as the input of another program The data path that joins the programs is called a pipe Pipes allow you to redirect program input and output without the use of temporary files When programs are connected with pipes the shell coordinates the input and output between the programs The pipes only transfer data in one direction from the standard output of one program to the standard input of another program How to
232. nd Its syntax is print Rnprsu n arg wae The print command provides a superset of the echo command for shell output It prints the specified args depending on the option set The options are R ignore all echo escape sequences except n n do not add a new line to output p write output to the process spawned with a two way pipe amp instead of standard output See Chapter 23 for two way pipes r ignore all echo escape sequences s save args in the history file un write to the file descriptor n This print command print s End of the day date history puts the comment End of the day following by a date in your history file This makes it easier to review the current day s command lines in the history file because the end of yesterday s commands is clearly marked The history command lists the last sixteen command lines executed 21 6 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Conditional Statements POSIX and Korn Shell provide constructs that allow a script to execute a designated set of command lines only if a special condition is met These are called conditional statements Discussed in this section are the following 21 conditional statements test if case select for and while Using the test Command This command evaluates expr if expr evaluates true test returns a zero exit status If expr evaluates false tes
233. nd back to the terminal screen Suppose you had placed a job in the background using the amp but now have decided to return it to the screen type fg job_number or type 4 4 or if it is the current job If it was the previous job meaning that you have typed another command after placing the command in the background use 4 The following example demonstrates how to brings a previous command du back to the foreground The second background process sleep command suspends execution of the shell for 999 seconds du sort gt diskusage amp 1 6100 sleep 999 2 6102 jobs 2 Running sleep 999 1 Running du sort gt diskusage fg du sort gt diskusage If you later decide you want your terminal free again first suspend the job then type bg to put it back into the background You can also use these two commands on suspended jobs to restart them in foreground or background 22 4 Controlling Jobs Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Killing Jobs Sometimes after you ve started a job and placed it in the background you realize it is an incorrect process and you do not want to run it In this type of instance you can destroy or kill a job 22 Suppose you start this process lsf sort gt filenames amp 1 6112 then realize you do not want to list the full file system that is you really didn t want to use in the
234. ndex FINAL TRIM SIZE Index P PAGER 26 30 parameter 3 2 9 3 15 6 definition 19 4 keyword 19 4 name 19 4 positional 19 4 19 6 setting 19 6 shifting 19 5 substitution 19 4 19 7 parameter passing 5 5 parameter positional 5 4 parameters 4 3 5 2 5 3 parameter shell 5 2 parameter softkeys 26 4 definition 27 4 parameters set by the shell 8 17 parameter substitution 5 3 parameter value definition 8 9 parenthesis 19 11 21 18 parent process 2 3 17 2 parent shell return to 10 4 parse 9 4 passing data to scripts 21 2 passing parameters 5 5 path 13 4 PATH 26 30 path 9 4 PATH 16 6 16 9 16 11 18 3 PATH environment variable 4 4 4 6 path name 3 3 9 4 path name completion 17 5 17 6 pattern matching 3 6 19 7 21 9 permission 4 1 9 4 PID 2 3 17 2 pipe 3 4 3 5 7 2 9 2 9 4 15 6 17 1 pipeline 15 6 pipes two way 23 4 placing softkeys 26 23 positional parameters 5 4 19 4 19 5 19 6 Index 9 7 5 in x 9 0 in Index POSIX Shell definition 15 1 16 1 overview 1 2 versus other shells 15 3 postfix operators 13 8 PPID 16 9 16 11 17 2 precedence of commands 23 7 previous events modifying 11 5 print 21 2 21 4 21 6 23 4 24 25 print accumulated user and system times 8 15 print commands as shell is executed 8 10 printing conventions 25 5 printing data 21 4 21 6 process 9 4 16 2 process child 17 2 process id 16 2 process identifier
235. ng another program such as vi or mailx Thus you can include metacharacters in text being processed by such programs without concern for their significance to C shell Syntactic Metacharacters separates commands to be executed sequentially separates commands in a pipeline Commands in a pipeline execute sequentially with the output of one command being fed as input to the next command Q isolates commands separated by or pipelines such that the result appears as a single command Thus pipelines enclosed in parentheses can be used as components in another pipeline Commands enclosed within parentheses are always executed in a subshell amp indicates command s must be executed as a background process For example to print the file letter as a background process on the system printer spooler type pr letter lp amp l separates commands or pipelines in such a manner that the second is performed only if the first fails amp amp separates commands or pipelines in such a manner that the second is performed only if the first succeeds Part Il C Shell Aliases Substitution Metacharacters 12 5 FINAL TRIM SIZE 7 5 in x 9 0 in 12 12 Filename Metacharacters If a file name contains one of the metacharacters listed below the name is a candidate for file name substitution File name metacharacters can represent patterns or identify abbreviations Characters representing patterns indicate that the
236. ning this shell certain terminology is used to describe commands and arguments If you don t know the following terms and definitions becoming familiar with them will help you understand later descriptions argument and parameter the words following a command or program name used to pass information to that command or program m an argument is given to a command In the example lp filet file1 is the argument and 1p is the command m a parameter is something that has a value possibly null or empty In the example X 12 X is a parameter variable and parameter are usually interchangeable blank a tab or space character Sometimes called a whitespace character command is a subset of word A word is a command if it is the first word in a command line that is not a redirection or variable assignment metacharacter One of the following characters amp lt gt new line space and tab options or flags a letter preceded by a dash and separated from the command name by a blank For example v word a sequence of characters separated by one or more non quoted metacharacters or whitespace For example date The five types of words the shell understands are reserved words such as for built in command names such as pwd alias such as type functions and utility names such as a path name 15 6 Introducing the Shells Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in simple c
237. ns on the print command select command and function command for features unique to the POSIX and Korn Shell Creating and Executing Shell Scripts Shell scripts are command lines that the shell executes in a group The files profile and kshrc are examples of shell scripts To create a script edit a file using an editor such as vi If you don t know how to create a file using an editor see The Ultimate Guide to the vi and ex Text Editors or Using HP UX After you create the script the file containing your command lines you are ready to execute it First make sure the file script is executable type chmod x script_name This command changes file permissions on the new file so that it is executable If you want more details on file permissions see Using HP UX Then type the script_name that is the script filename script_name and the script executes and prints out any output you specified Part Ill POSIX and Korn Shell Basic Shell Programming 21 1 FINAL TRIM SIZE 7 5 in x 9 0 in 21 Commenting When writing a program commenting the script helps someone else reading it to understand the code Comments in the shell start with an unquoted and continue through the first unquoted newline Comments may start anywhere on the line This script prints out every executable file for i in 1s for all files in the current directory The entire first line is a comment and in the second line e
238. nt the circumflex argument specifier selected the second argument on the event s command line and the h modifier used only the head of the specified argument is used users jack documents To return to your home directory type 18 cd 19 An Example To see how this all comes together let s try to debug the following C program To do this example use an editor to create the file bug c as shown by event 22 below 22 4 cat bug c Prompt set to show current command number main printf hello 23 cc Compile file named in last event cc bug c bug c line 3 unterminated string or character constant bug c line 4 unterminated string or character constant bug c line 5 unexpected lt end of file gt bug c line 5 syntax error at lt end of file gt 11 8 Command History Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 11 24 ed Edit file named in last event ed bug c 31 38 amp p printf hello W 32 q 24 c Do last event that began with small c cc bug c character 25 a out hello 26 e Not right run ed again ed bug c 32 3s 1o 1lo n p printf hello n W 34 q 26 c o bug Do the last c event and append the o cc bug c o bug option and word bug 27 size a out bug a out 792 408 84 1284 bug 792 408 84 1284 28 ls 1 Prefix last event s arguments with an ls l a out bug ls
239. nted out and the last time z is printed out When the list is completely finished the loop is exited Part Ill POSIX and Korn Shell Command Reference 24 17 FINAL TRIM SIZE 7 5 in x 9 0 in 24 function Syntax function name shell_script or name shell_script The function command is used to modularize programs To create a function use function followed by the name and a shell script enclosed between curly braces or use just the name followed by parenthesis and then shell script Nothing is required or allowed inside the parenthesis To invoke the function type the name followed by any positional parameters that need to be passed in as arguments Recursion is possible by using the typeset command listed later in this chapter See Chapter 21 for details on functions Example function exef gt gt if x 1 gt then echo 1 is executable gt fi gt exef script This simple function takes a file name 1 as an argument and checks whether it is executable If it tests true it prints out that the file is executable 24 18 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in if The if statement allows you to execute one or several commands if a certain condition exists 24 Syntax if command_line then conditional cmd_linel else conditional_cmd_line2 fi First if checks whether command_line is true If it is then conditional_cm
240. nth option softkey Your screen should look like that in Figure 26 5 The softkey menu now shows the months of the year Notice that two banks of for_month softkey options are available cal for_month E Select a month Help january february march j More 1 of 2 Figure 26 5 Using Invisible Softkeys 26 10 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in 4 Select the More softkey to see the second bank of options Selecting More again returns you to the first bank of options 5 Select any month then press Return keysh displays the HP UX equivalent then executes the command Using Standard HP UX Commands You can also use keysh as you would any shell by simply typing HP UX commands and options You do not have to use the softkeys at all 26 For example to see how the standard commands work follow these steps 1 At the keysh prompt type uname Do not press Return yet 2 Ignore the softkey options that appear Type a n then press Return 3 Your screen should look like that in Figure 26 6 The uname n command displays your node name uname n hpfcjdp E hpfcjdp users jodi keysh No mail 03 52 49 PM i Display Print Figure 26 6 Using Standard HP UX Commands Part IV Key Shell Getting Started With Key Shell 26 11 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Editing the Command Line
241. ntroduced in the POSIX Shell The POSIX Shell sh is named the same as the Bourne Shell but is put in bin posix directory The Bourne Shell in put in the bin directory What is Key Shell Key Shell is a softkey interface for the Korn Shell It was developed by Hewlett Packard Company It provides menus and online help to assist you in building commands to perform such tasks as viewing files printing files and listing contents of directories It is also user extensible in that you can create your own softkeys and online help Choosing Between the Shells m With the Key Shell new users can comfortably start with the Korn Shell and use the Key Shell interface to ease into the syntax and power of the Korn Shell a If you feel comfortable with a command line driven shell the Bourne Shell might be the place to start Remember that you can later migrate to the Korn Shell if you want its interactive or programming features a If you are a C programmer the C Shell may be a good starting point since you will already be familiar with the C Shell syntax 1 2 Introduction to Shells FINAL TRIM SIZE 7 5 in x 9 0 in m The POSIX Shell is the future HP UX Shell and also the standard Shell in the HP UX environment It is fully compatible with HP UX Korn Shell and also conforms to the standards defined in POSIX IEEE P1003 2 Table 1 1 lists some additional features which may help you make a decision on which shell would be best for t
242. o SHELL 16 bin posix sh The echo command prints out the contents or value specified by using before a parameter name of the SHELL variable SHELL is set to the name of the current shell at login The rest of this section explains how to change over to the POSIX or Korn Shell on a temporary or permanent basis Running POSIX or Korn Shell from the Current Shell If you would like to experiment with the POSIX or Korn shell until you gain expertise invoke it by simply typing bin posix sh or bin ksh In this manner you are starting another shell on top of your current shell sometimes referred to as a subshell If you run this shell from the Bourne Shell the prompt does not change However if you are in the C Shell when you invoke the POSIX or Korn Shell the prompt changes from to unless these prompts have been redefined It is possible to redefine prompts see PS1 in Table 16 1 Shell Parameters If you exit the shell by typing exit you must reinvoke it each time with the sh or ksh command Other methods of exiting the shell are discussed in Terminating the Shell Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 3 FINAL TRIM SIZE 7 5 in x 9 0 in 16 Specifying Your Login Shell To make ksh your permanent or default login shell type chsh login_name bin ksh where login_name is your user name The chsh command change shell changes your default login shell set in the
243. o those found in the C programming language The syntax for this command is name expression nameLindex expression The first form is equivalent to set print csh variables The second form sets name to expression The third form sets the indexth component of name to expression both name and its indexth components must exist Arithmetic Operators In an expression of this type the following C arithmetic operators are allowed Q Parentheses change the order of evaluation Addition Subtraction Multiplication 13 6 Shell Variables Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in Division h Remainder Bitwise exclusive OR Unary one s complement Boolean Operators The following boolean operators are allowed String comparison equal I Boolean not equal Exclamation point for negation Furthermore the following are also allowed but must be enclosed in parentheses and their operands must be separated by white spaces as in Coperand gt operand gt Boolean greater than lt Boolean less than gt Boolean greater than or equal lt Boolean less than or equal gt gt Right shift lt lt Left shift amp Bitwise AND Bitwise inclusive OR amp amp Logical AND Logical OR Assignment Operators The following assignment operators are recognized Assignment As in x y is the compressed form of x x y Part Il C Shell Shell Variables FINAL TRIM SIZE 7 5 i
244. ocesses Kill process kill Terminates a process Manual page man Accesses the online manual pages 26 Keysh config kc Configures the appearance and behavior of keysh Adding Invisible Softkeys The pre configured invisible softkeys are listed in Table 26 4 These commands do not show up on the softkey menu but if you type one of them keysh will recognize it and display the appropriate softkey options You can also create your own invisible softkeys as described in Chapter 27 To add additional invisible softkeys follow these steps 1 Select Keysh config softkey add invisibles 2 By default invisible softkeys are added from usr keysh C softkeys If you want to add invisible softkeys from another file do either of the following a Select from file then type the name of the file containing the softkeys you want to add Then press Return b Select from user then type the name of the user whose HOME softkeys file contains the softkeys Then press Return For example to add all invisible softkeys from user rpt use this command Keysh config softkey add invisibles from user rpt Return Part IV Key Shell Getting Started With Key Shell 26 19 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Table 26 4 Invisible Softkey Commands Softkey Function adjust Performs simple text formatting ar Creates and maintains library archives bdf Displays free disk space cal Displays a calendar canc
245. ogramming 5 9 FINAL TRIM SIZE 7 5 in x 9 0 in The result of this command will generate the following The banner command HHHHH O RHERHE HEHH HHHHH E HERE tt FH FE F HHH 4 HHHHH HH Be sure to try these commands yourself Conditions The if Statement Your shell programs may need to execute a command or set of commands only if a certain condition exists Let s say you want to execute the sort command only if the file exists otherwise print an error message Your statement would look like if test f 1 then sort 1 else echo file does not exist fi where 1 is a filename passed in from the command line The if statement checks the status of the command following it in the above case the test command follows The else statement is executed if the command in the if statement fails For the case of if this then that else if this then that etc we can use the elif statement which means else if The format for the if construct looks like if command_list1 then command_list2 elif command_list3 then command_list4 5 10 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in else command_listn fi It is helpful to indent to indicate parts of the if construct Make sure you end the construct with fi Let s look at an example to better clarify this const
246. ommand or command line identifier or name a sequence of blank separated words which may be include options and parameters The first word specifies the name of the command to be executed For example cat v filename 15 A command line may contain many simple commands In the command line cat file rm file who the three simple commands are cat file rm file and who a sequence of letters digits or underscores starting with a letter or underscore Identifiers are used as names for aliases functions and named parameters For example new_program_1 pipeline a sequence of one or more commands separated by the metacharacter which is called a pipe For example 1s file_list print_script list a sequence of one or more pipelines separated by amp amp amp or and optionally terminated by amp or amp For example sort o temp pr temp lp rm temp amp Part Ill POSIX and Korn Shell Introducing the Shells 15 7 FINAL TRIM SIZE 7 5 in x 9 0 in 15 Conventions The following conventions are used throughout this tutorial Italics indicate manual names and references to manual pages in the HP UX Reference For example see date 1 in the HP UX Reference Italics is also used for symbolic items representing parameters or variables typed by the user Italics is also for general emphasis Boldface is used when a word is first introduced or defined Computer font indicates a literal that
247. onal parameters separated by blanks use this is useful if the positional parameters constitute a sentence or even a command line Positional parameters are accessed within the body of the script When the script is executed the parameters are assigned values only for the execution of the script To make the parameters retain their values in the current shell see The dot Command in Chapter 6 Here is an example script using positional parameters echo Searching for 1 in 2 grep 1 2 echo Done This shell program expects two positional parameters The first parameter is a string and the second is a file The grep command searches the file for each occurrence of the string Here is an example of how we would type in the shell program for execution let s call the program search search widget 20809 users dave datafile The 1 parameter is widget 20809 and the 2 parameter is users dave datafile Notice the quotes around the first parameter If you need to include a blank in a positional parameter you have to quote the expression Quoting is discussed later in this chapter Shift In the last section we learned how to access the positional parameters by using the numbers 1 through 9 However if we access these by name we must already know what to expect In other words we cannot have the positional parameters in an arbitrary order nor more than nine The shift operation helps alleviat
248. onment 4 3 9 2 16 4 environment variable CDPATH 4 6 HOME 4 6 IFS 4 6 MAIL 4 4 4 6 MAILCHECK 4 6 MAILPATH 4 6 PATH 4 4 4 6 PS1 4 5 4 6 PS2 4 6 5 1 setting in C Shell 10 6 SHACCT 4 6 SHELL 4 6 TERM 4 4 environment variables 10 6 15 8 16 4 equal 21 15 Master Index FINAL TRIM SIZE 7 5 in x 9 0 in error codes 8 16 error messages 26 5 error output 3 2 error standard 17 10 esac 6 4 escape character 19 12 21 4 escape key 17 5 17 6 20 2 20 4 etc passwd 16 1 16 3 etc profile 16 4 etc profile file 26 3 eval 6 6 24 11 evaluating file status 13 9 event arguments modifying 11 6 event number 11 3 events re executing 11 2 events referencing 11 2 event text 11 3 exec 8 7 24 12 executable files 21 1 21 14 executing commands 3 4 8 1 executing commands in shell 6 6 executing nonsequential commands 3 2 executing scripts 14 10 21 1 executing sequential commands 3 1 executing shell programs 4 1 execution 9 2 exit 5 13 5 15 16 14 24 13 exit a loop 6 8 exiting 16 14 exiting Key Shell 26 2 exit status 5 13 expansion file name 17 5 17 6 path name 17 5 17 6 expansion metacharacters 12 9 export 4 4 16 4 16 7 18 3 24 14 exporting aliases 18 3 exporting variables 16 4 expr 8 7 8 8 expressions shell script 14 12 Master Index Index F fc 20 2 20 5 24 15 FCEDIT 16 9 16 10 20 8 features Key Shell 25 2 Korn Shell 25 2 features o
249. ontinue until you supply this information string lt files gt disable 1 enable all editrule append argument required Enter the name of the file s to copy Part IV Key Shell Customizing the Key Shell 27 19 FINAL TRIM SIZE 7 5 in x 9 0 in 27 The following example of hint text is from the Change dir softkey If you do not specify a directory to move to you move to your home directory by default Hence the directory name is not required and can be prompted for with a hint string lt dir gt editrule append argument hint Enter the name of the directory to move to Adding Help Text To add help text to a softkey follow these guidelines m Start the text with the keyword help m Enclose the text in quotes mw You can make the text any length m Use the backslash to escape special characters within the text such as quotation marks 27 20 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Online help that you create is accessed in the same way as the pre configured online help You determine how the text will look with a few simple formatting commands described in Table 27 5 These commands are a subset of the man 5 macro commands used by nroff 1 Table 27 5 Formatting Commands Command Meaning br Force a break in the current output line Display subsequent text on the next line sp Force a break and then display a single blank line Pp Force
250. or you can type them over several lines For example we can type the following construct two ways don t worry what the construct actually does just how it can be typed First on one line if test d di then echo d1 is a directory fi Then on several lines if test d dl then echo d1 is a directory fi Typing the command on one line is simple to do in the shell If you type the command on several lines you will receive a secondary prompt which you can define in the PS2 variable The secondary prompt is usually a gt So if you were to type the above command on several lines the screen would look like if test d di gt then gt echo d1 is a directory Part Bourne Shell Basic Shell Programming 5 1 FINAL TRIM SIZE 7 5 in x 9 0 in gt fi di is a directory where is the system prompt What is more you can create shells from programs such as notes mail and most editors such as vi and execute shell commands from these shells Running a shell from another program is usually called forking a shell It may be useful if you are writing a program and wish to test the program you can edit the program in vi fork a shell from vi by typing sh execute the program to see if it works exit the new shell by typing CTRL d and be right back in the editor to make any changes Parameters In addition to shell parameters you can create parameters of your own The format fo
251. ory Part Ill POSIX and Korn Shell Substitution Capabilities 19 3 FINAL TRIM SIZE 7 5 in x 9 0 in 19 Parameter Substitution A parameter is an entity that holds a value The two types of parameters discussed in this section are m named parameters such as HOME IFS m positional parameters such as 1 2 3 Each of these is described in detail in the subsequent sections Parameter substitution is the process the shell does to a command line when it replaces the parameters with their value for example changing echo HOME to echo users mary Then after parameter substitution the line is executed The echo command never see the HOME it is the shell that does the substitution The value of a named parameter can be accessed by preceding the name with a dollar sign parameter where the specifies substitution of the value of the parameter For example x 1 echo x 1 This is a simple example of a parameter which is named x that is assigned a value 1 19 4 Substitution Capabilities Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Setting and Using Keyword Named Parameters At the risk of sounding circular a named parameter is a parameter with a name The name may be any word consisting only of alphanumeric characters and the _ underscore and beginning with an underscore or alphabetic 19 character new_progi is a named parameter The value of a named parameter can be set
252. our profile which is read only at login time add SHDEPTH 1 initial depth incremented in kshrc export SHDEPTH Then in your kshrc file which is read whenever a shell starts up depending on how you configure things add SHDEPTH SHDEPTH 1 if SHDEPTH 0 then PSi useful with ENTER key on HP terminals else PSi SHDEPTH fi Now in your login shell your prompt will be and in subshells it will be 1 2 etc where the number indicates the nested depth of the shell Note The POSIX Shell also provides the p option with the export command The p option formats the output so that it is suitable for re input to the shell as commands that achieve the same exporting results 24 14 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in fc Syntax 24 fc e editor nlr first last fc e old new command The fc command is one of the three methods used for listing and editing command_lines In the first form fc searches the history file for the command lines that contain the commands specified by strings first through last and acts on them according to the option specified nlr The second line invokes the editor to replace the old string with the new string in command_line specified by command and then execute the new version Example fe l fe e The first line lists the last 16 commands you have exe
253. path name of a directory The variable 1g contains the long path name and executing cd lg moves you to the abbreviation of long path name directory Note the dollar sign placed before a parameter in this case 1g designates using the value of that parameter The alias command is explained in Chapter 18 and the set command is explained in Chapter 23 The trap command line is explained in Terminating the Shell The above example just gives you an idea of the types of things to put ina ENV file You can create your own HNV file using an editor but you must set the ENV variable to the name of that file in profile or the system does not read it when invoking a new shell For example if you use kshre as your ENV file the line in your profile file might look like export ENV HOME kshrec 16 8 Starting Stopping the Shell Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The set Command There is a command that displays current environment variables the set command If you type set a listing similar to this is displayed set 16 EDITOR usr bin vi ENV START _ 1 _ 0 _ _ i J START kshre FCEDIT bin ed OLDPWD usr bin HOME users mary IFS HISTFILE sh_history HISTSIZE 30 LOGNAME mary MAIL usr mail mary MAILCHECK 600 PATH bin posix bin usr lib usr bin users mary bin PPID 29590 PS1 PS2 gt PS3 PWD users mary ksht man
254. pattern is deleted These examples show how some of the parameter substitution techniques work To get the basename of a path prog users mary prog basename prog echo basename prog As you can see in this example the pattern users mary is matched and then removed from the string 19 8 Substitution Capabilities Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in To get the corresponding path prefix you could do the following prog users mary prog prefix progh 19 echo prefix users mary In this case the smallest substring starting on the right of users mary prog that begins with a that is matches is removed Part Ill POSIX and Korn Shell Substitution Capabilities 19 9 FINAL TRIM SIZE 7 5 in x 9 0 in 19 Special Parameters or array parameter array If the parameter is or then all the positional parameters starting with 1 are substituted For example the script sc uses to echo all its parameters at one time sc first second third echo first second third If the parameter describes an array with elements or then the value for each of the elements is substituted For example echo array An array is a collection of contiguous elements that can be accessed by a subscript A subscript can also be metacharacters such as and For more details on arrays see Chapter 21
255. ponse is not d or f else echo x not a correct response Part Bourne Shell Basic Shell Programming 5 15 FINAL TRIM SIZE 7 5 in x 9 0 in exit fi Discussion of Example Moving Files The shell program was created in the vi editor When the file was typed the permission was changed to allow the file to be executed chmod x move To execute the command you would type move followed by the name of a file you want moved 1 test if there are any arguments The first few lines which are preceded with a are comments Then the next few lines comprise an if construct This construct uses the test command indicated by the square brackets which compares the number of positional parameters to zero If there are no positional parameters then an error message is printed and the shell is exited 2 ask if file is to be moved to directory or file After the next comment the main body of the program begins The user is prompted to type a d or P to indicate whether the file is to be moved to a directory or to another file The read statement accepts input from the keyboard 3 test if x is a directory if not leave script Next the parameter x is tested to see if it is equal to d The construct x will exit with an error message parameter null or not set if the user just hits return If a d is typed then the user is prompted to enter the name of the directory and the move command is executed using 1 the
256. profile 4 5 custom softkeys 27 1 Index 3 7 5 in x 9 0 in Index creating 27 23 format 27 4 cwd 13 2 D data paths 3 2 date 17 3 debugging 7 1 default aliases 18 3 18 8 default environment for Key Shell 26 2 default shell 16 3 default variables 16 12 defining functions 8 3 defining rules aliases 18 6 definition of softkeys 27 3 definitions 2 3 deleting softkeys 26 23 device file 9 1 directory structure 8 13 disabled softkeys 27 3 disk 9 1 display of softkeys 26 2 division 8 7 21 15 do 6 1 done 6 1 dot command 6 5 double quote 5 8 double quotes 17 9 driver number 9 1 du 22 2 E echo 4 5 5 2 5 7 5 15 14 1 16 3 16 14 17 3 19 6 21 2 21 4 24 10 echo command 4 2 edit 9 1 editing command line 26 12 editing command lines 20 1 editing in line 20 4 editing lines 20 2 editing mode 20 1 20 2 Index 4 EDITOR 16 6 16 9 16 10 20 2 20 4 editrules 27 8 27 9 append statement 27 12 blanks 27 14 combining expressions 27 11 dash statement 27 13 edit statements 27 9 examples 27 15 expressions 27 10 if statement 27 13 word list 27 9 edit statements 27 9 ellipses 15 8 C 3 6 elm mailer 26 17 else 5 10 emacs 20 2 emacs in line editing mode 20 4 enabled softkeys 27 3 enabling emacs editor mode 20 4 enabling vi editor mode 20 2 endif 14 14 entering commands 26 4 26 8 ENV 16 4 16 7 16 9 16 10 18 3 23 1 envir
257. programs in their present form or with alterations is expressly prohibited All rights reserved Copyright 1980 1984 1986 UNIX System Laboratories Inc FINAL TRIM SIZE 7 5 in x 9 0 in Printing History New editions of this manual will incorporate all material updated since the previous edition The manual printing date and part number indicate its current edition The printing date changes when a new edition is printed Minor corrections and updates which are incorporated at reprint do not cause the date to change The manual part number changes when extensive technical changes are incorporated January 1991 Edition 1 This Edition documents material related to shells relevant to the 8 X release of HP UX m Bourne C and Korn replace the like named parts of manual part number 97089 90062 Edition 3 dated October 1987 Changes were made to each of these parts to update incorrect or confusing information m Key Shell is new functionality for the 8 X release of HP UX a PAM replaces the PAM chapter of manual part number 98515 90004 Edition 1 dated September 1989 Changes were made to update incorrect or confusing information and to reflect PAM software changes effective for the 8 X release of HP UX August 1992 Edition 2 This Edition documents material related to shells relevant to the 9 X release of HP UX m POSIX Shell is new functionality for the 9 X release of HP UX a PAM not supported in the 9 X
258. pt is printed and the lines read from standard input are placed in REPLY SECONDS Returns the number of seconds since the shell was invoked SHELL The path name where the shell itself lives This refers to the user s preferred shell TMOUT If this parameter is set to a value greater than zero and you do not enter another command or Return within that number of seconds the shell terminates VISUAL When this variable is set and ends in emacs gmacs or vi then the corresponding set o option is turned on See the set command in Chapter 23 The following variables are set automatically at login HOME PPID PWD OLDPWD RANDOM REPLY SHELL and SECONDS These variables are given default values in the default login script PATH PS1 PS2 PS3 MAILCHECK TMOUT and IFS Again use the set command to check these values before editing or creating a profile that changes them 16 12 Starting Stopping the Shell Part Ill FINAL TRIM SIZE 7 5 in x 9 0 in POSIX and Korn Shell Terminating the Shell There are two ways to exit exit and CTRL D_ or whatever the EOF character is set to see stty 1 The ignoreeof flag turns CTRL_ 0_ on off The value of ignoreeof is assigned with the set command i e by typing set 16 o ignoreeof See Chapter 23 for details To determine the current value of ignoreeof type set o This lists all currently defined variables and their value
259. ption after you have selected the softkey An invisible softkey command Type the command Select Help then press Return If you have entered more than one softkey on the command line and you want to see help for an earlier softkey backspace to that softkey Then select Help and press Return For example to see the online help for Print files and its options follow these steps 1 Select Help 2 Select Print files The help for this command is displayed 3 Select Print files again to actually select the command 4 Then select Help again and select the double spaced option The help for this option is displayed Note that simply typing help at the keysh prompt gives you a prompt from the help 1 command This help has nothing to do with Key Shell online help Part IV Key Shell Getting Started With Key Shell 26 7 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Entering Commands Key Shell provides three methods of entering commands Using visible softkey commands The softkey commands shown on the top level softkey menu banks are called the visible softkeys listed in Table 26 3 Using invisible softkey commands keysh recognizes approximately 70 common HP UX commands for which softkey options are available listed in Table 26 4 These commands are called invisible softkey commands because they do not appear on the top level softkey menus However when you type the comm
260. ption is selected all other nodes on the same level are disabled enable count Selecting this softkey node enables count softkey nodes to the right of this one and all the nodes to its left count can be a positive or negative integer or the word all The default is 0 The line option search enable 12 in a softkey definition means that when the search option is selected the next 12 nodes on the same level are enabled filter command This softkey node is only active for filters or commands A filter is a command used after a pipe P A command is used by itself or as the first command in a pipeline By default a softkey node can be used in either place The line softkey Move_files command in a softkey definition means that the Move files softkey can only be used as a command by itself or as the first command in a pipeline disabled This softkey node is initially disabled and must be enabled to be used By default softkeys are initially enabled The line option to disabled in a softkey definition means that the to option cannot be selected unless you first select another softkey that enables it Part IV Key Shell Customizing the Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in 27 7 27 27 Table 27 1 Softkey Attributes continued Attribute Meaning Example automatic Selecting this softkey node will automatically execute the comm
261. que temporary file names The form lt is replaced by the next line of input read from the shell s standard input instead of using the next line in the script being processed This is useful when writing interactive shell scripts For example echo yes or no set a lt would write the prompt yes or no to the shells standard output device and then read the answer from the shells standard input device into the variable a Note You need the single quotes or no expands to all files that start with no and have a single character after the o Shell Script Expressions Construction of useful shell scripts requires that it be possible to evaluate expressions in the shell based on the current values of certain variables In fact most C language arithmetic operations are available in the shell with the same precedence that they have in C In particular the operations and compare strings while the operators amp amp and implement the boolean AND OR operations The special operators and are similar to and except that the string on the right side can have pattern matching metacharacters like or and the test is whether the string on the left matches the pattern on the right The shell also allows file inquiries of the form filename where is replaced by a number of characters 14 12 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0
262. r fc e true type whence v who who sort Part Ill POSIX and Korn Shell Aliasing 18 5 FINAL TRIM SIZE 7 5 in x 9 0 in 18 Special Aliasing Features Several things you should keep in mind when defining aliases are m Unlike the C Shell you can alias the alias command For example alias a alias In this example whenever you use a an alias is created such that a who who sort will set who to an alias m Reserved keywords such as while do and done cannot be changed by aliasing m The first character of an alias name can be any non special printable character but the following characters must be alphanumeric alias Q w who sort gt user Here w now checks who is on the system sorts the names and places them into a file called user m The replacement value on the right hand side of the aliasing sign can contain any valid shell script name or the script itself For example alias i echo Users logged in are who sort echo I am whoami PvVVV 18 6 Aliasing Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in If you execute the alias you will get something like the following i Users logged in are mary tty2 Sep 24 14 19 michael tty4 Sep 24 09 41 18 nick ttyl Sep 24 09 41 I am mary Creating scripts is described in Chapter 21 m Aliases take effect only after the alias command has been executed If you try to run a script
263. r position to the end of the command line Alternately press Back space to back up past all_info 4 Select scheduler info 5 Now suppose you decide to cancel the command altogether To do this simply press Delete line 26 14 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Configuring Key Shell You can configure Key Shell s appearance and behavior through several options These options are accessed with the Keysh config softkey or the special kc command You can make the following changes to keysh a Adding moving and deleting softkeys a Changing global options 26 m Changing the status line m Saving configuration changes m Restarting keysh m Undoing any configuration changes The following sections describe how to do each of the above Adding Moving and Deleting Softkeys This section explains how to add visible and invisible softkeys move softkeys and delete softkeys If you encounter errors while adding softkeys refer to the online help topic Errors Softkey Names and Labels All softkeys have names which are the HP UX commands they correspond to Visible softkeys the softkeys that appear on the top level softkey menu also have labels which are the words that appear on the softkey itself Labels allow you to give a less cryptic name to a command For example Search_lines is the less cryptic label given to the grep command A label can have a
264. r shell programs Here is an example eval grep jones p_file set echo 1 2 4 eval will execute the pipe contained in double quotes in the shell If you use the following s date amp s 6 6 Advanced Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in you would receive an error message from date The amp is ignored as a special character due to the single quotes So to make the command function as expected use eval s eval date amp s and the eval will reparse the string and thus attach the special meaning to amp Using Shell Expansions You read about pattern matching in File Name Generation in Chapter 3 Here are some examples which will simplify some of the constructs you just learned When you generate lists for your for constructs or any other construct where you are trying to generate filenames without needing to type in each file name you are free to use pattern matching characters For example for i in c do mv i tmp done Here we generate a loop in which i is set to each filename in the current directory that ends in c case i in dD c echo i nN mv i 3 exit esac This case construct will match the value of i on the first pattern line if it begins with any single character 7 followed by either d c or D c The second pattern line matches any string including the null ending in any let
265. r user created parameters is parameter value Note that there must be no blanks between the parameter equal sign and the value You can create these parameters while you are in the shell and they will help you save typing Look at an example x phantom When you type in the above statement the variable x is created and the value phantom is assigned To access the variable x you will need to precede the variable name with a dollar sign Try this echo x The echo command writes the value of x on the screen One possible use of parameters is to assign a long pathname to a variable so you do not have to type the whole pathname each time you wish to use it For example diri users hpux davek projects shellp 5 2 Basic Shell Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in So to list the contents of this directory type ls dir1 Using Parameters in Shell Programs You can use parameters within your shell programs in the same way On one line define the variable with the same format When you wish to refer to the value of the parameter you precede the parameter name with a dollar sign One advantage of using parameters in a program is that you can combine them with each other or with file names to create a variety of file paths with less typing Let s say you define a parameter to be the path to a directory dir2 users hpux dave projects memos If you want to print the content
266. rd error into the standard output And you can use the lt amp capability in a similar manner to use as standard input The order in which you place the redirections is significant The shell evaluates redirections from left to right 1 gt fileA 2 gt amp 1 will first associate file descriptor 1 thus it is no longer associated with standard output with the file fileA Then file descriptor 2 is associated with the file with file descriptor 1 which is fileA If we had placed the 2 gt amp 1 first file descriptor 2 would be associated with file descriptor 1 the terminal and then file descriptor 1 would be associated with fileA To force both the standard output and error output into the same file you usually use a statement like gt file 2 gt amp 1 To close standard input use lt amp To close standard output use gt amp 8 6 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Special Commands The following are commands which may be of help to you in your shell programs Exec The exec command allows you to replace the current shell with a new shell or another program With the syntax exec arg where arg can be a sequence of commands or shell programs This command can be helpful in cases where you do not wish to create subshells You could have no desire to return to the parent shell or you may be recursing and do not wish to keep parent shells active A good example is a she
267. reates an alias then removes it Note The POSIX Shell provides the a option to the unalias command This option removes all the aliases from the current shell environment Part Ill POSIX and Korn Shell Command Reference 24 41 FINAL TRIM SIZE 7 5 in x 9 0 in 24 unset Syntax unset fv name The unset command removes the specified name or function that has been set by the shell You must use the f option to unset a function and the v option to unset a variable Variables with readonly set cannot be unset Example param 6 echo param 6 unset param echo param The variable param is set to 0 and the unset unsets the variable 24 42 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in wait wait Syntax wait process_ id The wait command suspends the shell until the spawned process process_id terminates and then reports the processes termination status If process_id is not specified currently active processes are waited for The shell resumes after all processes terminate or when it receives a signal such as Break Example contemplate gravity amp mailx wait rm gravity In this example you run a very slow program contemplate in the background then read your mail and when done wait for the background job to finish if it hasn t already before removing the file it used Note For POSIX Shell the exit status of wa
268. release PAM information removed m Shell comparison information added from The Beginner s Guide to HP UX part number B1862 90000 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Contents 1 Introduction to Shells What are Shells 2 2 2 2 a a a 1 1 What is Bourne Shell 2 2 ee 1 1 What is C Shell 2 2 2 1 1 What is Korn Shell 2 2 aa e 1 1 What is POSIX Shell 2 2 ee 1 2 What is Key Shell 2 2 ee 1 2 Choosing Between the Shells 2 2 2 ee 1 2 Changing Shells re 1 4 Determining Your Login Shell e 1 4 Temporarily Changing Your Shell a a a a aaae 1 5 Permanently Changing Your Shell 2 aaa aaae 1 5 Part I Bourne Shell 2 The Bourne Shell UNIX System Structure 2 2 ee 2 2 Definitions 2 2 a a a a a a 2 3 Conventions oo aoa a a a 2 4 3 Shell Commands Sequential Processing a 3 1 Nonsequential Background Processing a 3 2 Redirecting Input and Output a a a a a 3 2 How to Redirect Input and Output a a a aaa aa 3 3 Examples noa aa 3 4 Pipes e e 3 4 How to Connect Programs With Pipes e e 3 4 Redirection in Pipes a a a a a a a 1 ee ee 3 5 Shells Contents 1 FINAL TRIM SIZE 7 5 in x 9 0 in Examples Pipe Example File Name Generation 4 Shell Scripts Introduction to Shell Scripts Simple Scripts a Scripts With More Than One Line Echo and Redirection in Scripts The profile File Customizing profi
269. resource is the book by Morris I Bolsky and David G Korn The Kornshell Command and Programming Language You will also find useful related and supporting information in other other HP UX documentation References to these manuals are included where appropriate in the text m The HP UX Reference contains the syntactic and semantic details of all commands and application programs system calls subroutines special files file formats miscellaneous facilities and maintenance procedures available on the HP UX Operating System a Using HP UX presents new users with information on oc how to log in to HP UX work with files and the directory structure and send and receive mail o the basic elements of what a shell is how to use it and what shells are available on HP UX o how to create edit and save files using the vi editor Additional tutorial information for the vi ex sed and awk editors and processors are contained in The Ultimate Guide to the vi and ex Text Editors and in Text Processing User s Guide a Finding HP UX Information provides part numbers for and brief overviews of the contents of manuals available for working with the HP UX operating system Finding HP UX Information is available online as a Helpview Help module under HP UX 9 0 Operating System Help a Common HP UX Tasks is available online as a Helpview Help module under HP UX 9 0 Operating System Help Common HP UX Tasks covers many of the topi
270. rmat is as follows newgrp group where group is the new group and the option will cause the environment to be changed to what it would be if you logged in again you lose your old shell and get a new one With no arguments the group is changed back to what your password entry file indicates For more information see newgrp 1 in the HP UX Reference 8 14 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Times This command prints the accumulated user and system times for processes run from the shell The times are precise to units of 1 HZ seconds where HZ is processor dependent The output looks like Om37s Om25s For more information read times 2 in the HP UX Reference Ulimit This command provides control over process limits The format is ulimit fp n where n is the size limit imposed by ulimit The f option imposes a size limit of n blocks on files written by child processes with no argument the current limit is printed The p option changes the pipe size to n If no option is given the f option is assumed Wait The wait command will wait until the specified process is finished and then report its termination status To specify the process use this format wait n where n is the process id Most of the time you will not know the process number but if you look ahead to the section Parameters set by the shell you will notice one entry refers to the process n
271. rminated Note that without double quotes around 1 in the test the test will respond with an argument expected syntax error when 1 NULL Until The until construct is basically the same as the while construct except that the commands in the loop are executed until the conditions are true instead of false like in the while loop Here is the format until command list1 do command list2 done If the last command in command list1 is unsuccessful then the commands in command list2 are executed When the last command in command list is Part Bourne Shell Advanced Programming 6 3 FINAL TRIM SIZE 7 5 in x 9 0 in successful the until loop is terminated Let s use the same operation in the while section to illustrate until r 1 do cat 1 gt gt composite done Notice the subtle difference with the while loop The negates the test conditions We execute the loop until the condition is true or successful The while loop executes the commands while a condition is true or successful Case The case construct is an expansion of the if construct If you have a condition which may have several possible responses you can either string together many if s or you can use the case construct case parameter in patternit pattern2 command list1 pattern pattern3 command list2 esac After the first line which asks if parameter matches one of the following conditions is listed all o
272. rns a code which tells the shell to print an error message You can use the exit command to leave a shell program with a certain exit status see below for a table of the codes The default exit no arguments will exit the shell program with the status of the last command executed You can exit with a different exit status see the HP UX Reference pages for the exit statuses of each command The usual exit statuses are Table 5 1 Exit Status Value Description 0 Success 1 A built in command failure 2 A syntax error has occurred 3 Signal received that is not trapped see the trap command For example the statement exit 0 will give the instructions to leave the shell program successfully Comments To add to a shell program comments simply start the line with a pound sign For example this line is a comment Part I Bourne Shell Basic Shell Programming 5 13 FINAL TRIM SIZE 7 5 in x 9 0 in Or you can add a comment after a statement as long as you precede it with the pound sign Note Do not start your shell script your file containing the script with the pound sign If the first character in a script file is the system will think the script is a C shell csh script You may choose to always start your shell script files with a blank line or always include a space before you use the pound sign in comments Example Moving Files The following example uses all of
273. rpreter and a high level programming language It is used to translate command lines typed into the system into system actions such as running programs moving between directories and controlling the flow of information between programs csh has several useful features including a Command History Buffer and associated history substitution facility Recently executed commands can be modified and re executed with ease m an aliasing mechanism Useful statements can be referenced with a short alias m an extensive C like command and control capability For additional information about HP UX shells consult the Bourne Shell part of this manual Note This software and documentation is based in part on the fourth Berkeley Software distribution under license from the Regents of the University of California We acknowledge the following individuals and institutions for their role in its development William Joy This document uses the following conventions m All examples assume the C Shell prompt has been changed to show the current command event number by entering the following set command in either HOME cshre or HOME login set prompt 4 Part Il C Shell Preparing to Use the Shell 10 1 FINAL TRIM SIZE 7 5 in x 9 0 in 10 10 This prompt will appear as 23 _ m Computer font is used to show what should appear on the screen For example to activate the C Shell type csh Terminating command
274. rs umask Sets file creation mode mask uname Displays the name of the current HP UX version vi Edits files on a screen oriented display we Counts lines words and characters in a file who Lists who is logged on to the system write Interactively writes to another user xd Creates a hexadecimal dump of a file xdb C FORTRAN and Pascal symbolic debugger 26 22 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Moving Softkeys To change the placement of a visible softkey follow these steps 1 Select Keysh config softkey move 2 Type the name or label of the softkey you want to move 3 Select where you want the softkey to be moved then press Return If you select before softkey you will need to type the name or label of the existing softkey before which you want the other softkey to be moved 26 For example to move the Mail softkey to immediately before the Keysh config softkey use this command Keysh config softkey move Mail before softkey Keysh_config Return Deleting Softkeys To delete a visible softkey follow these steps 1 Select Keysh config softkey delete 2 Type the name or label of the softkey you want to delete 3 Press Return For example to delete the Edit file softkey from the top level softkey menu use this command Keysh config softkey delete Edit_file Return Note that after deleting a softkey from the softkey menu you can still access th
275. ruct if grep jones personnel then echo jones gt gt available elif grep castle personnel then echo castle gt gt available else echo empty gt gt available fi This construct will attempt the first command list grep jones personnel If the string jones is found in the personnel file then the command echo jones gt gt available will be executed If the search for jones fails we go to the elif statement and try the grep castle personnel command If this is successful the command echo castle gt gt available will be executed If this grep command is unsuccessful we go to the else statement and execute the echo empty gt gt available command Test An often used command is the test command You can use the test command in the if construct to test conditions such as equality There are many options we will not mention here so you may wish to refer to the test 1 entry in the HP UX Reference Here are two examples to explain the use of the test command diri usr bin if test diri usr bin then echo directory found fi Part I Bourne Shell Basic Shell Programming 5 11 FINAL TRIM SIZE 7 5 in x 9 0 in This construct tests if the value for dir1 notice how we used parameter substitution is equal to the string usr bin if test eq 0 then echo no positional parameters fi The eq option is used to test the numeric equivalence of the and the value zero Remember
276. ry Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 11 Table 11 1 Previous Event Modifiers continued Modifier Definition Effect t tail Remove all elements of a path name except the last element i e the path name s tail amp repeat Do the previous substitution again The history substitution facility keeps track of the last substitution you performed with the s modifier thus enabling you to easily perform the same change on various events that you want to re execute For example suppose we enter the following commands 14 car users jack documents memo car Command not found 15 The cat command in event 14 was misspelled To fix this type 15 14 s car cat cat users jack documents memo This is a test 16 This executes the command correctly without retyping the whole path name of the file that you want to look at To look at a file called list in the same directory you can now enter 16 15 s memo list cat users jack documents list apples oranges bananas pineapples strawberries plums 17 Part il C Shell Command History 11 7 FINAL TRIM SIZE 7 5 in x 9 0 in 11 Now suppose that you want to move to the directory containing the files that you just looked at You can do this with 17 4 cd h cd users jack documents This is quite a complex command but typing is still saved The double exclamation marks specified the immediately previous eve
277. ry part of the HP UX operating system that keeps track of and assigns system resources to each user It also coordinates I O operation and performs other software functions A shell is a program that acts as an interface between the system and each user The shell interprets user commands then performs system calls to the kernel or loads and runs programs according to the commands given by the user See Figure 15 1 Part Ill POSIX and Korn Shell Introducing the Shells 15 1 FINAL TRIM SIZE 7 5 in x 9 0 in 15 15 2 Bourne Shell utilities Figure 15 1 System Structure Introducing the Shells Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in POSIX and Korn Shell Versus Other Shells The POSIX and Korn Shell programs are command interpreters and programming languages that execute commands entered from a terminal or file They are based on features found in the Bourne Shell and C Shell POSIX and Korn Shell maintain Bourne Shell s superior programming environment while adding the unique command interpreting features of C Shell They are 95 upward compatible with the Bourne Shell and most programs written under the Bourne Shell will run under the POSIX and Korn Shells without change In developing POSIX and Korn Shell some of the features of the C Shell were also incorporated This blend creates a powerful shell with improved human interface features and faster execution performance Features From
278. s then the value of the parameter is set to the corresponding word and REPLY is set to the input line i e the number If this line begins with anything else parameter is set to the null If you input nothing type Return it reprompts for input No matter which way it evaluates the command_lines are executed The loop continues until a break is encountered Example select char inaeiou gt do gt echo char is a vowel gt done 1 a 2 3 4 5 4 Return o is a vowel 7 em all the vowels in words are printed out with a number in front The default PS3 prompt 7 is printed and waits for a number and Return to be typed in When it receives the number it echos that the corresponding letter is a vowel then prompts for the next entry It continues prompting until you press Break If you designate 6 which is not set a null is a vowel is returned ec OF 24 30 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in set set Syntax For POSIX Shell only 24 set taCefnuvx o option arg Lee For Korn Shell only set taefhkmnostuvx to option arg wee This command is used to set shell options as well as reset the values of positional parameters arg See Chapter 23 for a detailed explanation of the various options available with set Example set If you just type set it lists all your currently set s
279. s For example set o Current option settings allexport off bgnice off emacs off errexit off gmacs off ignoreeof on interactive off keyword off markdirs off monitor off noexec off noglob off nounset off protected off restricted off trackall on verbose off vi off viraw off xtrace off Part Ill POSIX and Korn Shell Starting Stopping the Shell 16 13 FINAL TRIM SIZE 7 5 in x 9 0 in 16 In this example ignoreeof is on If ignoreeof is off you must type exit to terminate the shell Using exit Normally you logout using exit or CTRL D If you try to logout using a CTRL D with ignoreeof set the system responds Use exit to logout To log out type exit If ignoreeof is not set use CTRL D or exit to logout Executing a logout Script If you want some special action to occur when you logout use the trap command Although not all traps are generated by a signal for example DEBUG EXIT trap can capture a signal then execute a predefined command This means you can set a trap on some condition then the action will take place when the condition arises If a file named HOME logout a file named logout in your home directory exists and the following trap statement is in your profile logout is executed when you logout Add this to profile trap HOME logout 0 This trap statement causes the shell to execute the logout script in your HOME directory when the shell exits
280. s such as a file To redirect stdin from a file use the lt symbol To redirect stdout to a file use the gt symbol To redirect stderr to a file use the 2 gt symbol Table 17 4 Input Output Redirect Operators lists and gives examples using the redirection characters 17 10 Shell Grammar Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 17 4 Input Output Redirect Operators Redirect Example Description Operator lt word mail joe lt letter The less than operator lt redirects the contents of letter to input to mail gt word ps gt processes The greater than operator gt redirects output from ps into the processes file deleting any current contents gt gt word date gt gt processes The double greater than operator gt gt redirects the output from date and appends it to the end of the processes file If the file does not exist a new one is created lt lt word cat lt lt eof The double less than operator lt lt reads the shell gt write input typed after the cat command line at the gt until PS2 prompts gt up to a line which is identical to gt eof word eof word is not subjected to file name or write parameter substitution The resulting document until is commonly called a here document If is appended to lt lt all leading tabs are stripped from word and from the resulting document lt amp digit echo output 1 gt amp 2
281. s and prompts you to correct them before executing the command Part IV Key Shell Introducing the Key Shell 25 3 FINAL TRIM SIZE 7 5 in x 9 0 in 25 25 Who Should Use Key Shell Key Shell provides features for both the novice and the experienced user If you do not have much experience with HP UX you can use the pre configured softkeys to enter basic HP UX commands You can also learn HP UX syntax as you go Key Shell shows you how your readable softkey commands translate into standard HP UX Read Chapter 26 to learn about starting using and configuring Key Shell If you are a more experienced user but use certain HP UX commands infrequently the softkey options provided for those commands can serve as memory joggers You can also customize Key Shell to meet your needs For example you can create your own custom softkeys and online help Read Chapter 26 to learn the basics of Key Shell and how to configure it then refer to Chapter 27 for information on advanced use and customization 25 4 Introducing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Conventions This part of the manual uses the following typographic conventions Boldface Words defined for the first time appear in boldface For example enabled softkeys are softkeys that appear on the softkey menu Computer Computer font indicates literal items either typed by the user or displayed by the system For example
282. s assigned a job number as it starts The job number can be used later in later references to the job if needed Upon completion the job number is canceled and can be assigned by the system to another job When a job is started in the background using amp its number as well as the process numbers of all its top level commands is printed by the shell before prompting you for another command For example ls s sort n gt usage amp 2 2034 2035 h runs the 1s program with the s option pipes the resulting output into the sort program with the n option which places its output in the file usage The amp at the end of the line runs two pipelined programs as a background job After starting the job the shell prints the job number in brackets 2 in this case followed by the process number of each program included in the job The shell then prompts for a new command as soon as the background job is underway To check to see what jobs are currently being run use the job command For example 42 jobs 1 lowercase L not 1 provides a list of current jobs and their corresponding job numbers the commands being executed as part of each job and the process IDs of each command The running or stopped status of each job is also listed 14 8 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 14 C Shell Scripts Shell scripts are files containing a series of commands
283. s being accessed 4 begin main loop The main loop tests several options and executes the appropriate action For example if the query option q is set it asks the user if he she wants a file to be copies or not Part I Bourne Shell Advanced Programming 6 13 FINAL TRIM SIZE 7 5 in x 9 0 in 5 parameter is not a directory Finally if the parameter supplied is not a directory an error message is returned Study the example and read the comments in the code Then type it into a file and try to run the program yourself By typing it in you may come to understand the constructs and how they operate better than just reading the code on a page in a manual Some additions you may wish to try are to selectively copy files that have a c suffix C source files 6 14 Advanced Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Programming Tips This chapter presents some tips for programming in the Bourne Shell Debugging When you use pipes in shell programs it becomes difficult to debug since you do not see output from commands in the pipe One suggestion to help debug pipes is to add cat statements in the pipes to show you what the intermediate output would be For example you could add a cat command followed by an exit at one point in a pipe The pipe will then list the output at that stage and it will exit the program to avoid further errors and to indicate exactly where in the pipe you are
284. s command removes the values previously assigned to a variable by a set command The unsetenv Command This command removes the specified variable s from the current environment 14 6 Commands Jobs and Scripts Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 14 Jobs When one or more commands are typed together as a pipeline or as a sequence of commands separated by semicolons a single job is created by the shell consisting of these commands together as a unit Single commands without pipes or semicolons create the simplest jobs Usually every line typed to the shell creates a job Some lines that create jobs one per line are sort lt data ls s sort nlhead 5 mail harold If the metacharacter amp is typed at the end of the commands then the job is run in the background and C Shell returns immediately with a prompt ready for another command The job continues running to completion in the background while normal jobs called foreground jobs continue to be read and executed by the shell one at a time Thus du gt usage amp runs the du program which reports on the disk usage of your working directory as well as any directories below it puts the output into the file usage and returns immediately with a prompt for the next command without waiting for du to finish The du program continues executing in the background until it is finished freeing you and the terminal to execute more commands in the mea
285. s for each command You can use these softkeys to build a complete command without having to remember and type cryptic HP UX commands or options Visible softkey commands Twenty two pre configured softkey commands appear on the top level softkey menu These softkeys allow you to perform HP UX functions such as changing directories listing files and printing files Invisible softkey commands keysh also recognizes approximately 70 common HP UX commands as you type them and provides softkey sub menus showing options for those commands Softkey command translation After building a softkey command you can see it translated into HP UX syntax before it is executed Status line A configurable status line near the bottom of the screen can display your hostname username current directory mail status time date and any other text you specify The status line also displays prompts or messages from keysh User configurability You can customize keysh s appearance and behavior You can also add move and delete softkeys and create custom softkeys and online help Support for keyboard editing keys You can use the standard editing keys such as Delete line and Insert char to edit the command line You can edit the softkey command line or the translated command line Softkey error detection and correction For softkey commands keysh immediately notifies you of syntax error
286. s of a file in the above directory you would use the cat command as follows cat dir2 junememo where the braces differentiate between the parameter and the characters following it and junememo is the name of a file note we had to include a slash before the filename or junememo would have been concatenated directly to memos and we would have received an error message What has happened is called parameter substitution and will be discussed next Parameter Substitution When you wish to include the value of a parameter into a string or statement you must precede the parameter with a dollar sign Also the following conventions hold parameter The value of the parameter in the brackets is substituted Use the brackets when the parameter is followed by a letter digit or underscore which is not part of the parameter Example dir1 123_file will substitute the value for diri and append the characters 123_file Part Bourne Shell Basic Shell Programming 5 3 FINAL TRIM SIZE 7 5 in x 9 0 in parameter word If the parameter is set and non null the value will be substituted Otherwise the word will be substituted Example dir1 usr bin If dirt is null then usr bin will be substituted parameter word If the value of parameter is not set or null then set the value to word and substitute that value Example dir1 usr bin If dirt is null its new value is usr bin parameter
287. s place 24 32 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in test test Syntax 24 test expr or expr or LLtest_expression This command tests or evaluates the expr and if it evaluates true returns a zero exit status If it evaluates false it returns a nonzero exit status The test command can be replaced by appropriately spaced brackets A extensive list of expr forms are covered in the HP UX Reference in the test1 entry Four exprs limited to the POSIX and Korn Shell are L file Returns true if file is a symbolic link file nt file2 Returns true if file is newer than file2 fiel ot file2 Returns true if file is older than file2 file ef file2 Returns true if file has the same device and i node number as file2 One expr unique to the POSIX Shell is e file Returns true if file exists Part Ill POSIX and Korn Shell Command Reference 24 33 FINAL TRIM SIZE 7 5 in x 9 0 in 24 test Example for file in ls gt do gt if x file gt then echo file is executable gt fi gt done This script tests a file for executability using brackets around the expression and then prints that the file is executable if the expr returns true if file nt oldfile a file ot newfile gt then echo file is newer gt fi This example echos the filename only if it is newer then the filename in oldfile and older than
288. s precedence order Notice in Table 23 1 that POSIX Shell precedence is different from Korn Shell for function and built in Table 23 1 Precedence Order for Korn and POSIX Command Words Order Korn Shell POSIX Shell 1 reserved word reserved word 2 alias alias 3 built in function 4 function built in 5 other e g path name other 23 8 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The set Command The set command is used to turn on and off shell options such as tracking or automatic exporting of commands Its second function is to reset the values of positional parameters 1 23 The set command syntax for POSIX Shell is set taCefnuvx o option arg and the set command syntax for Korn Shell is set taefhkmnostuvx o option arg where arg specifies the positional parameters to be reset and option can specify with a word the same meaning as the aCefhkmnostuvx letters For example you can turn the verbose option on in two ways set v or set o verbose Here is an example showing results before and after the verbose option is set echo hello hello set o verbose echo hello echo hello hello The set o verbose causes the shell to print each line as it is read and then print the output of that line Part Ill POSIX and Korn Shell Advanced Concepts 23 9 FIN
289. s that can be executed from emacs mode that allow you to search the history file CTRL p Specifies the previous command CTRL n Specifies the next command forward CTRL r string Specifies a search for the most recent command that contains string So if you used the same set of commands fc 1 20 11 a 21 more file 22 ps 23 pwd and you executed an CTRL p the shell displays CTRL p pwd For every CTRL p typed after that the shell displays one line further back at the same prompt Then if you go too far backwards in the history file come forward using the CTRL n For example ps CTRL pwd If you want to specify a line with a certain string use CTRL r such as cTRL 1 11 ll a Once you find the command line you are searching for you simply re execute it by typing a Return or edit it using the emacs in line edit commands and then re execute it 20 12 Command lines and Command History Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in 21 21 Basic Shell Programming The POSIX and Korn Shell are not merely command interpreters they are also programming languages with all the standard constructs needed to write detailed shell scripts This chapter discusses the major constructs of the shell such as inputting and outputting data conditional statements and functions New users should read this entire chapter advanced users should see the sectio
290. se word is substituted For example unset x echo x x is unset x is unset parameter word If parameter is not set or null the value is set to word s value parameter word If parameter is set and non null substitute its value otherwise print word and exit from the shell When word is omitted a standard message is printed parameter word If parameter is set and non null substitute word otherwise substitute nothing Part Ill POSIX and Korn Shell Substitution Capabilities 19 7 FINAL TRIM SIZE 7 5 in x 9 0 in 19 Note For the above four substitutions with the colon if the colon is omitted the check for a null value is omitted xs echo x x is null x is null echo x x is null A parameter pattern If the Shell pattern matches the beginning of the value of parameter tpattern the parameter substitute the value of the parameter with the matching pattern removed otherwise substitute the value of this parameter In the first form the smallest matching pattern is deleted and in the latter form the largest matching pattern is deleted parameterh pattern If the Shell pattern matches the end of the value of parameterhn pattern parameter then the value of parameter with the matched part deleted is substituted otherwise substitute the value of parameter In the first form the smallest matching pattern is deleted and in the latter form the largest matching
291. selectors to on an uppercase selector character appears in each softkey label Typing this character unquoted selects the softkey keysh automatically sets selectors to on if you are using a terminal that does not support a sufficient number of softkeys translations Enabled If you set translations to off keysh will not display the HP UX translations of softkey commands before executing them visibles Enabled If you set visibles to off keysh will not display softkey commands on the top level softkey menu If you are familiar with HP UX commands but not necessarily with the options you may wish to set visibles to off You can then decrease keysh start up time by editing keyshrc and removing the lines that add visible softkeys Part IV Key Shell Getting Started With Key Shell 26 25 FINAL TRIM SIZE 7 5 in x 9 0 in 26 26 Changing the Status Line In the Keysh config status line menu an asterisk next to a status line indicator means that the indicator is on You can turn the various status line indicators on and off with the following commands Keysh config status line indicator_softkey on Keysh config status line indicator_softkey off For example to add your user name to the status line use this command Keysh config status line user name on Return Table 26 6 describes status line indicators Table 26 6 Status Line Indicators Indicator Default Description user
292. sent as input into the sort command which outputs the sorted list of people on the system to the display For example who michael tty02 dave tty03 mary tty00 george tty04 keith tty05 who sort dave tty03 george tty04 keith tty05 mary ttyOl michael tty02 Two Way Pipes Two way pipes or co processes can be established between the shell and a job The parent process is the original shell and the child process or subprocess is the job the command or shell spawned from the parent shell The standard input and output of the spawned command can be written to and read from the parent shell in a two way pipe A two way pipe is created by placing the amp metacharacter after the command to be executed See Chapter 23 for details on two way pipes 17 2 Shell Grammar Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Command Separators and Terminators Certain metacharacters are used by the shell to either separate or terminate commands in a line as well as perform special functions to the shell For example 17 date ls amp where is the separator and amp is the terminator The date command prints out the current date and the 1s command lists the files in the current directory Table 17 1 Separating and Terminating Characters describes each of the special characters used by the POSIX and Korn Shells For each special character there is an example command line followed by that exampl
293. sequences with Return is assumed m Actual file names like sh_history and variable names like histsize are in computer font m Placeholders for file names like filename and variables like printername are in italic font Several HP UX commands are useful in setting up and verifying shell operation They include chsh change login shell rlogin used to access remote systems over a local area network printenv lists currently defined environment variables with their corresponding values set sets or lists system variables setenv used to set shell environment variables to a given value Refer to the HP UX Reference section 1 for detailed information about these commands HP UX Standard Shells HP UX systems support the Bourne Shell the C Shell the POSIX Shell and the Korn Shell command interpreters The normal shell prompt for the Bourne POSIX and Korn Shells is the dollar sign When C Shell is active instead the default prompt becomes the percent 4 symbol The prompts for any shells can be changed to any character s you want but more about that later 10 2 Preparing to Use the Shell Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 10 Shell Startup and Termination Running C Shell From the Bourne Shell The name of the C Shell program is bin csh To run C Shell from the Bourne Shell type csh Your prompt changes to the C Shell prompt unless you have redefined the C Shell
294. sh global option settings o Status line contents Your keyshrc is automatically updated every time you change Key Shell s configuration You should not need to edit this file manually Part IV Key Shell Getting Started With Key Shell 26 3 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Using Key Shell This section explains guidelines for using Key Shell and describes how to get online help enter commands and edit commands It includes examples for you to try Guidelines for Using Key Shell The following list provides general guidelines for using Key Shell m Select softkeys by pressing the corresponding function key on your keyboard or by clicking on the softkey with your mouse m Always select softkeys from left to right Do not attempt to insert words or options out of order on the command line a Follow the prompt messages describing required actions m To see additional softkey commands or options use the More softkey This softkey toggles through banks of softkeys showing your position a Option softkeys insert the corresponding command or option into the command line For example selecting Change dir inserts Change_dir into the command line a Enter your own text for string softkeys String softkeys or parameter softkeys are enclosed in angle brackets and indicate that you need to type text on the command line for that parameter or string such as a user name or file name For example for the softkey
295. sh should simulate softkey labels rather than using the built in labels on HP terminals When you use simulated softkey labels keysh also shows an input mode indicator between the two groups of four softkey labels This indicator shows your current command line editing mode For example vi insrt means that vi 1 is the editor and it is in insert mode Part IV Key Shell Getting Started With Key Shell 26 29 FINAL TRIM SIZE 7 5 in x 9 0 in 26 Table 26 7 Key Shell Variables continued Variable Description KEYTSM If set and Terminal Session Manager is running specifies that keysh should not display TSM softkeys LANG Defines the language in which softkeys and Key Shell messages are displayed The default is C LC_TIME Defines the format to use for time and date display on the status line The default is american LINES Defines the number of lines in the terminal screen if different than the terminfo 4 default PAGER Defines the pager to use for displaying online help The default is more 1 PATH Defines the search path for commands TERM Defines the terminal type TZ Defines the time zone to use for time and date display on the status line 26 30 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Using Key Shell with Terminal Session Manager If you are using Key Shell with the Terminal Session Manager tsm 1 note the
296. signated option or flag F This flag provides UNIX to host name file mapping on non UNIX machines L Left justify and remove leading blanks from value If n is non zero it defines the width of the field otherwise it is determined by the width of the value of first assignment When the parameter receives a value it is filled on the right with blanks or truncated to fit into the field Leading zeros are removed if the Z flag is also set This turns the R flag off R Right justify and fill with leading blanks If n is non zero it defines the width of the field otherwise it is determined by the width of the value of first assignment The field is left filled with blanks or truncated from the end if the parameter is reassigned This turns the L flag off Z Right justify and fill with leading zeros if the first non blank character is a digit and the L flag has not been set If n is non zero it defines the width of the field otherwise it is determined by the width of the value of first assignment e Tag the parameter as having an error This tag is currently unused by the shell and can be set or cleared by the user f The names refer to function names rather than parameter names No assignments can be made and the only other valid flag is x i The name is an integer This makes arithmetic faster If n is non zero it defines the output arithmetic base otherwise the first assignment determines the output base 1 All uppercas
297. sitional parameter is A positional parameter is B positional parameter is C In the previous example the current shell is the Korn Shell The POSIX Shell behaves differently compared to Korn Shell with respect to the 0 positional parameter The same example in the POSIX Shell prints sh for the 0 parameter if the login shell is POSIX or bin posix sh for the 0 parameter if the login shell is not POSIX This happens because within the POSIX Shell definition the positional parameter 0 is either the shell filename if the shell is interactive or is the script name 19 6 Substitution Capabilities Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The set command may be used to set the positional parameters for the shell set first second third acho 1 2 3 19 first second third This sets positional parameter 1 to first positional parameter 2 to second and positional parameter 3 to third Parameter Substitution Conventions This section covers special conventions used during parameter substitution parameter Braces are required when parameter is followed by a letter digit or underscore that you do not want be interpreted as part of the parameter s name for example 1s tmp tfile _text Braces are also required for enclosing multi digit positional parameters for example 17 parameter word If parameter is set and non null its value is substituted otherwi
298. sses A pipeline causes the output of the process before the vertical bar to be the input of the process after the vertical bar amp forms a pipeline between two processes that sends diagnostic output as well as standard output from the first process as input to the second process Expansion Substitution Metacharacters indicates variable substitution For example set Mi usr man man3 cd M1 The pathname is assigned variable M1 To use the variable precede the variable name with a dollar sign Note that you could also execute cd M1 C Shell then looks for a directory called M1 and when it cannot find it proceeds to search for a variable of that name When the variable is found its value is used as an argument to cd indicates history substitution See discussion in Chapter 11 precedes substitution modifiers See discussion in Chapter 11 used in special forms of history substitution indicating command substitution Other Metacharacters indicates shell comments and begins scratch file names Must be the first character in a line to be executed by C Shell v prefixes job name specifications For example 56 cc test c gt amp test amp 1 3265 57 kill 1 58 Event 57 kills the background process with the job number 1 Part Il C Shell Aliases Substitution Metacharacters 12 9 FINAL TRIM SIZE 7 5 in x 9 0 in 12 Using Metacharacters as Normal Characters Metachar
299. stitution Conventions in Chapter 19 for other possible array subscripts and uses for arrays Part Ili POSIX and Korn Shell Basic Shell Programming 21 17 FINAL TRIM SIZE 7 5 in x 9 0 in 21 Writing Functions The function command is for writing modular programs Modular programming is the concept of placing frequently used code in a certain area module of the shell script so you can call the module or function whenever it is needed rather then repeat the same code The function s syntax is function name shell_script or name shell_script where using function creates a module called name and shell_script is placed between curly braces Just using name followed by parenthesis and the shell script also creates a function Calling Functions To invoke the function type the name of the function followed by any arguments that need to be passed to the function Following is a function that takes a file name 1 as an argument and checks whether it is executable If it tests true it prints out that the file is executable function exef if x 1 then echo 1 is executable gt gt gt gt fi gt exef script script is executable where the argument the shell_script is the executable file script 21 18 Basic Shell Programming Part Ili POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in In a larger program this function is easily called by sp
300. stom softkeys and online help The following list gives some example uses for custom softkeys a If you frequently change to certain directories you could create your own Change dir command and add the directories you most often move to as options a If you often invoke an application you could create a softkey command for the application and add the application s options in a sub menu a If you frequently use an HP UX command with the same set of options you could create a softkey command for the entire HP UX command line the Part IV Key Shell Customizing the Key Shell 27 1 FINAL TRIM SIZE 7 5 in x 9 0 in command plus its options This softkey command acts as a macro so you do not need a sub menu for options a If you often send electronic mail to the same people you could add the names of those people as options to your own version of the Mail softkey How Key Shell Stores Softkey Information keysh stores softkey information in softkey files Softkeys are defined as a hierarchy of softkey nodes The top level of this hierarchy represents the softkey command itself The lower levels represent command options and parameters 27 Figure 27 1 illustrates the softkey node hierarchy using the Keysh config softkey as an example Figure 27 1 Example Key Shell Node Hierarchy 27 2 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Softkey Navigation As you build a softkey command
301. sus other shells 15 3 ksh flags 23 11 Kshrc 16 4 16 7 16 8 21 1 23 1 kshre file 26 3 L labels for softkeys 26 15 leaving shells 5 13 let 21 15 24 23 limits process 23 17 LINES 26 1 26 30 Index 7 7 5 in x 9 0 in Index LINES 16 9 16 11 list 15 6 11 17 3 logging in 16 1 logging out 16 14 logical operators 13 7 login program 16 1 26 3 login scripts 4 3 login shell 1 4 10 3 login shell script file 10 8 Logout 16 14 logout 14 2 logout command 10 5 loop for 21 11 until 21 12 while 21 12 loops 6 1 lp 17 3 1s 17 3 17 7 18 3 Isf 17 3 M mail 17 3 17 10 MAIL 16 6 16 9 16 11 MAILCHECK 16 9 16 11 MAILCHECK environment variable 4 6 MAIL environment variable 4 4 4 6 mailers 26 17 MAILPATH 16 9 16 11 MAILPATH environment variable 4 6 mailx mailer 26 17 man page entries HP UX 25 5 marker 8 5 matching file names 17 7 matching patterns 3 6 19 7 21 9 menus softkey 25 3 26 2 message 9 3 messages error 26 5 message signals 8 11 Index 8 metacharacter 15 6 17 1 17 7 17 9 17 13 metacharacters 12 5 12 9 metacharacters expansion 12 9 metacharacters filename 12 6 metacharacters input 12 8 metacharacters output 12 8 metacharacters quotation 12 7 metacharacters substitution 12 9 metacharacters syntactic 12 5 metacharacters using as normal characters 12 10 modes command 20 3 20 4 emacs 20 4 enabl
302. t index in the word next softkey command being built last Indicates the last position in the softkey command being built next Indicates the position that would be next in the softkey command being built argument Indicates the user input for the softkey 27 10 Customizing the Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Part IV Key Shell You can combine simple expressions in any of the ways shown in Table 27 3 Table 27 3 Combining Expressions Combination Meaning Example string number string number number numbertnumber number number string amp string number string string string string number amp amp number number number number string Single character substring Multiple character substring Addition Subtraction Concatenation Negation Equality Inequality Logical and Logical or Logical not Grouping word last 0 alo 1 argument 1 argument 1 w amp argument 1 word last 0 x slast x amp amp y xlly x argumentt1 Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Customizing the Key Shell 27 11 27 27 Table 27 4 Assigning Values Table 27 4 shows how you can assign values to variables or indexed words Assignment Meaning Example variable string variablet number variable number vartable amp string wordLindex string word index number word index numb
303. t returns a non zero exit status Syntax is test expr or Lexpr As shown the test command can be replaced by appropriately spaced brackets dD An extensive list of exprs are covered in the HP UX Reference on the test 1 manual page Four exprs limited to the POSIX and Korn Shell are L file Returns true if file is a symbolic link file nt file2 Returns true if file is newer than file2 fiel ot file2 Returns true if file is older than file2 file ef file2 Returns true if file has the same device and i node number as file2 meaning that both refer to the same physical file One expr unique to the POSIX Shell is e file Returns true if file exists The conditional command L test_expression may also be used where test_expression is a combination of the above conditional primitives combined with the and operator amp amp the or operator and the negation operator Part Ill POSIX and Korn Shell Basic Shell Programming 21 7 FINAL TRIM SIZE 7 5 in x 9 0 in 21 Using the if Statement The if statement allows you to execute one or several commands if a certain condition exists The syntax is if command line then conditional_emd_line1 else conditional_cmd_line2 fi if checks for command_line true true means command_line returns 0 If true conditional_cmd_line1 executes if not conditional_cmd_line2 executes The following if statement checks whether x equals hello If so Welcome is print
304. t variables 15 8 16 4 equal 21 15 error standard 17 10 escape character 19 12 21 4 escape key 17 5 17 6 20 2 20 4 etc passwd 16 1 16 3 etc profile 16 4 Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in eval 24 11 exec 24 12 executable files 21 1 21 14 executing scripts 21 1 exit 16 14 24 13 exiting 16 14 expansion file name 17 5 17 6 path name 17 5 17 6 export 16 4 16 7 18 3 24 14 exporting aliases 18 3 exporting variables 16 4 F fc 20 2 20 5 24 15 FCEDIT 16 9 16 10 20 8 features of Korn Shell 15 3 features of POSIX Shell 15 3 fg 22 3 24 16 file name completion 17 5 17 6 file name substitution 17 7 file name substitution metacharacters 17 7 flags 15 6 16 10 23 9 23 10 23 13 23 14 for 21 11 24 17 foreground jobs 22 3 function 15 6 19 4 19 5 21 18 21 20 23 6 23 7 function 21 18 24 18 G global 16 4 16 7 gmacs 20 2 gmacs in line editing mode 20 4 H HISTFILE 16 9 16 11 20 5 history 20 5 history file 20 5 20 10 20 12 HISTSIZE 16 9 16 11 20 5 Part Ill POSIX and Korn Shell FINAL TRIM SIZE HOME 16 6 16 9 16 11 16 14 human interface 15 1 15 3 l identifier 15 6 if 21 8 24 19 IFS 16 9 16 10 ignoreeof 16 13 in line editing 20 1 20 2 20 4 input mode 20 3 input standard 17 10 inputting data 21 2 integer 18 4 23 13 integer arithmetic evaluation 21 15 interactive sh
305. tem variable TERM to recognize the HP 2622 as your terminal setenv TZ MST7MDT This command sets the time zone variable The example specifies U S Mountain Standard Time Mountain Daylight Savings Time Zone setenv PATH bin posix bin usr bin usr local bin etc users login_name This command sets the search pattern the system uses for finding commands set mail usr mail login_name Required to receive mail for HP UX alias h history Make the character h an alias for your command history file alias bye logout For some bye is easier to remember than logout as a session termination order news more Pipe the news through more 10 8 Preparing to Use the Shell Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 10 C Shell Termination When C Shell is your default login shell and you log off of the system not when you return to another shell that spawned C Shell C Shell looks for a file logout in your home directory and executes it if it exists Commands that are typically included in a logout shell script include the following Table 10 2 Logout Script Commands Command Meaning echo Print logout message to your echo x You are logged out now standard output stdout device echo date Prints your log out date and time sync Put all information stored in all buffers onto the system disk Part Il C Shell Preparing to Use the Shell 10 9 FINAL TRIM SIZE 7 5 in x 9 0 in FI
306. ter other than n or N The last expression matches anything left over Part Bourne Shell Advanced Programming 6 7 FINAL TRIM SIZE 7 5 in x 9 0 in Helpful Tips Let s wrap up this section with a couple of helpful items m To print a character that will beep to alert a user use CTRL G in an echo command m To add control characters to the vi editor you must first type CTRL y then type the control string m To break from a for or while loop use the break statement If you want to break out of a certain number of levels in a nested loop construct add break n where n in the number of levels of nesting As an example consider for i do while true do break 2 This break 2 gets you beyond the second done It breaks you out of two enclosing loops for and while done done m To continue with the next iteration of the enclosing loop use the continue statement To continue at the next iteration of the nth enclosing loop use continue n m For more items look in the sh 1 entry in the HP UX Reference Some of these features will be discussed in the next section 6 8 Advanced Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Example Groupcopy bool n query n dir n TEHE HE HE HE HE HE HE HE HE HE HE HE HE HE FE FE FE TE TE TE FE HE HE HE HE HE HE HE HE HE HE HE HE HE HE HE FE FE FE TE TE TE TE HE HE HE HE HE HE HE HE HE HE HE HE
307. that file For example HISTFILE users mary hist20 HISTSIZE 20 If you do not set these two variables in your profile the shell defaults to a file named sh_history of 128 lines The history mechanism keeps continuous record of the most recent commands you have executed even if you logout and back into the system many times or execute the commands in a subshell Part Ill POSIX and Korn Shell Command lines and Command History 20 5 FINAL TRIM SIZE 7 5 in x 9 0 in 20 20 Any command contained in HISTFILE is accessible to you for manipulation by either the fc command or line editing modes To list the current contents of your history file type history 20 11 a 21 more file 22 ps 23 pwd 24 lsf A listing comparable to this of the most recent commands you have executed is displayed with a number beside each command These numbers are useful for accessing the history file commands by number The history command is an alias for fc 1 The fc command is explained in the next section 20 6 Command lines and Command History Part Ili POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Using the fc Command There is a built in command fc fix command special to the POSIX and Korn Shell that allows you to list your history file or run an editor on a command line from the file Do not confuse this command with the fc 20 Fortran compiler command The syntax of the command is fc e ed
308. that the shell executes as a group The files Jogin cshre and logout are all shell scripts When Not to Use a Script While shell scripts are a valuable programming and operating aid there are some situations where scripts are not useful Many excellent commands and program libraries are provided with HP UX Before writing a script check your HP UX Reference A solution to your problem may already exist Running a Script A C Shell command script may be executed by typing in csh script_one arg_ arg_2 where script_one is the name of the shell script file to execute and arg_1 arg_2 is a list of optional arguments that may be required by the script C Shell places these arguments in the shell variable array argv as argv 1 argv 2 etc There is no argv 0 C Shell uses 0 to refer to argv 0 instead In this example 0 equals script_one C Shell then begins to sequentially read the commands from script_one If you want to be able to execute the script file directly without beginning the command line with csh edit the script file so that the first line is bin csh The hash mark is also used for comment lines in the script Next use the chmod command to make the file executable For example chmod 755 script_one makes script_one executable and readable for everyone and writable by you For more information on the chmod command see chmod 1 in the HP UX Reference Now when you type script_one Part Il
309. the a option with the unalias built in command This option can be used to remove all the alias definitions by typing at the shell command line prompt unalias a 18 8 Aliasing Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in 19 19 Substitution Capabilities Chapter 17 discussed file name substitution and completion This chapter discusses the other substitution concepts tilde parameter and command Substitution methods are used to speed up command line typing and execution New users should read this chapter completely advanced users should see Tilde Substitution Parameter Substitution and Command Substitution for special POSIX and Korn Shell features Tilde Substitution If a word begins with a tilde tilde expansion is performed on that word Note that tilde expansion is provided only for tildes at the beginning of a word that is find pbm abc has no tilde expansion performed on it Tilde expansion is performed according to the following rules a A tilde by itself or in front of a is replaced by the path name set in the HOME variable m A tilde followed by a is replaced with the value of the PWD variable PWD is set by cd to the new current working directory a A tilde followed by a is replaced with the value of the OLDPWD variable OLDPWD is set by cd to the previous working directory m If a tilde is followed by several characters and then a the s
310. the blank space when it adds the number to the command line string number enable all editrule word last amp trim argument required Enter the number of the first page to print or select thru 27 14 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Examples of Editrule Use This section contains annotated examples showing how editrules are used in softkey definitions Refer to the usr keysh C softkeys file for other examples Remove Files Command Line Example The following example explains the editrules that tell keysh how to construct an HP UX command from the softkey command Remove files interactively c Recall that this command was used as an example in the section titled How Key Shell Translates a Softkey Command The example shows the lines from the softkey file that define the parts of the above softkey command The annotations describe the effect of those lines rm is assigned the label Remove files in the keyshrc file softkey rm command editrule append rm option interactively disable 1 editrule dash i string lt files gt disable 1 editrule append argument required Enter the name of the file s to remove Part IV Key Shell 27 When you type rm or select Remove files keysh appends rm to the HP UX command line When you select the interactively option keysh appends a i to the HP UX command line When you typ
311. the files The file has several options you include options by typing a minus followed by a letter q will prompt you as each file is about to be copied and you can choose not to copy it d will look in subdirectories if that directory has any and then copy it to the new directory If no options are included all files in the directory not including subdirectories are copied to the new directory The format for the command is gp options directory where options are those described above and directory is the directory to where you want the files copied The program looks in the current directory for files to copy 1 test to make sure the directory parameter is included The first condition if eq 0 looks to see if the user included any options or a directory If they did not they are told how the gp command is used and the program ends 2 look for options The next section look for options is a for loop with a case This construct looks for options If none are found the default is assumed copy all files from the current directory to the directory specified If options are found an appropriate flag is set and the positional parameters are shifted 3 test if parameter is a directory If the parameter is a directory check if it is in the current directory and set the bool flag then in the next construct concatenate the entire pathname to the parameter name this is needed when a subdirectory i
312. the loop at the top If n is set resume execution at the nth enclosing loop Example for file inx yz gt do gt if x file gt then continue gt echo file is executable gt fi gt echo file is not executable gt done This script checks for all executable files If the file is executable the continue statement skips both following echo statements and starts another loop If the file is not executable the script prints that it is not executable If the file is executable nothing is printed Part Ill POSIX and Korn Shell Command Reference 24 9 FINAL TRIM SIZE 7 5 in x 9 0 in 24 echo Syntax echo arg This command writes to standard output all arguments args separated by blanks or a blank line if no arguments are specified Example var short echo This is a var example In this example echo prints the line This is a short example echo n nusage 0 argi arg2 gt amp 2 This example is a line that might appear in a shell script It prints to standard error two blank lines n and a usage message including the invocation name of the script designated by 0 Using double quotes rather than single quotes causes 0 to be interpreted Certain characters can be used for formatting echoed strings These escape characters must be preceded by a backslash and enclosed in double quotes for interpretation such as the n See Chapter 21 for a list of these
313. thin fact calls until the value of 1 is returned and is less than or equal to 2 Then the recursion stops the factorial of the number originally input is printed and the function is exited function fact integer x if 1 lt 2 then echo 1 else x 1 1 let x fact x x x 1 echo x fi fact 1 21 20 Basic Shell Programming Part Ili POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in 22 Controlling Jobs A job is a pipeline A simple job is one command typed to the shell More complex jobs consist of one or more commands typed together as a pipeline A complete line containing one or more HP UX or shell commands is sometimes called the command line Here is an example of a command line that the shell interprets as a job ps ef sort gt processes Creating Jobs The shell associates each pipeline with an integer job number Once a job is created you can monitor it or manipulate it The rest of this chapter covers the things you can do with jobs Whether you are an advanced or new user you should read this chapter Monitoring Jobs The shell keeps a table of all current jobs and their numbers To see a listing of the table type jobs The screen displays something similar to this if you have jobs running 1 Running lp processes 2 Done ps ef sort gt processes Part Ili POSIX and Korn Shell Controlling Jobs 22 1 FINAL TRIM SIZE 7 5 in x 9 0 in 22
314. tinue to run as usual While a program is running as a sequential process you have the option of waiting for the program to finish Nonsequential Background Processing Programs can also be run nonsequentially in which case each program runs without waiting for the previous program to complete This type of execution is more commonly called running in the background Follow the program name with amp to specify background processing programi amp program2 amp program3 amp This example runs program1 program2 and program3 in the background and returns a prompt to the user immediately Note that programs that write to the terminal or require input are poor choices for background execution since the output will be intermixed on the screen or the input may not be read by the correct program Redirecting Input and Output Every program has at least three data paths associated with it standard input standard output and standard error output Programs use these data paths to interact with you By default standard input stdin is your keyboard The default destination for both standard output stdout and standard error stderr is your screen Redirecting input and output is a convenient way of selecting what files or devices a program uses The output of a program that is normally displayed on the screen can be sent to a printer or to a file Redirection does not affect the 3 2 Shell Commands Part Bourne Shell
315. tions typeset f applies to Korn Shell only hash alias t history fc 1 integer typeset i applies to Korn Shell only nohup nohup r fc e true type whence v where false is the first word the alias name and let 0 on the other side of the sign is the value of the alias Then when the alias name false is used it is replaced by the assigned value of the alias let 0 The let command is used for arithmetic evaluation and is explained in Chapter 23 18 4 Aliasing Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in In the next example which applies to Korn Shell only the first word of a command line integer already has an alias defined by the system typeset i as shown in the previous example The function of the typeset command is to create a value and type for a parameter When you type 18 integer val 1 echo val 1 typeset i is substituted for integer and val is created and given the value 1 In this example typeset i val 1 is what is actually executed When you echo the value of val using the metacharacter you see it was given the value 1 For more details on the typeset see Chapter 23 When you create an alias in Korn Shell and then execute it the shell adds it to the table of aliases If you type alias you see additions to the list hcd echo hello cd false let 0 functions typeset f hash alias t history fc 1 integer typeset i nohup nohup p users george
316. tkeys 27 20 visible softkeys 26 16 addition 8 7 21 15 advanced shell programming 6 1 alias 14 1 24 2 alias 15 6 16 8 23 6 23 7 alias command 18 1 aliases 12 1 default 18 3 18 8 defining rules 18 6 exported 18 3 tracked 18 3 unsetting 18 8 aliasing 18 1 aliasing features 18 6 alias substitution 12 2 alias unaliasing an 12 3 alias use restrictions 12 3 altering event arguments 11 6 argument 15 6 Index 1 7 5 in x 9 0 in Index argv 13 1 arithmetic evaluation 21 15 arithmetic operations 8 7 arithmetic operators C 13 6 array 19 10 21 17 asking questions 5 10 assignment operators 13 7 attributes of softkeys 27 6 autologout 13 1 automatically set variables 16 12 automatic scripts 4 3 background command process number 8 17 background jobs 22 3 background process 16 10 17 3 background processes 7 2 9 1 background processing 3 2 back quotes 17 9 19 11 back slash 17 9 backslash 5 7 backup softkeys 27 23 banner 5 9 beep 6 8 bg 22 3 24 4 bin csh 16 1 bin ksh 15 1 16 1 bin posix sh 15 1 16 1 bin sh 16 1 blank 15 6 block special files 9 2 bold 15 8 boolean noclobber 13 2 boolean notify 13 3 boolean operators 13 7 Bourne shell 26 1 Bourne Shell 2 1 15 3 16 1 16 3 commands 3 1 overview 1 1 running C Shell from 10 3 Index 2 brackets J 15 8 17 7 21 7 22 1 break 7 2 break 24 5 break from a loop 6 8 break statement 21
317. to a null value The next two sections start the two background processes first a comment is echoed to the screen so you know the process was started then the process is started in the background using the amp operator then the parameter proc is set to the process id of the process just run the parameter is the process id if you recall The line containing the trap command looks for the signal 2 which means interrupt When this signal is received it executes the commands in the double quotes kill proc will kill the two background processes since proc is a list of the process ids The last command section starts the foreground process So when this script is executed the three processes are run If you press the Break key the trap is activated killing the two background processes processi and process2 The foreground process process3 is automatically terminated Part Bourne Shell Programming Tips 7 3 FINAL TRIM SIZE 7 5 in x 9 0 in FINAL TRIM SIZE 7 5 in x 9 0 in Detailed Reference This chapter will cover the remaining concepts and commands associated with Bourne Shell programming So far you have learned how to write a shell program with conditions loops user prompts and other options This section discusses executing commands defining functions input output special commands return values and executing the sh command Command Separators When you execute commands in a shell progra
318. to file descriptor n Example print s End of the day history This print puts the comment End of the day in your history file Then you can easily determine the current day s commands when looking at your history file Part Ill POSIX and Korn Shell Command Reference 24 25 FINAL TRIM SIZE 7 5 in x 9 0 in 24 pwd Syntax pwd This command prints the current working directory Example cd pwd users guest The first line places you in your HOME directory and pwd prints where it is 24 26 Command Reference Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in read read Syntax For POSIX Shell only note that name must be specified 24 read r name vee For Korn Shell only read prsu n name prompt name wee This shell input mechanism reads a line from standard input and places each word into the parameter name using the separator specified by the IFS shell parameter If names are not specified the line is read into the Korn Shell REPLY variable see select If the prompt is included the user is prompted interactively with prompt The definitions of the options are p Read from the output of the process spawned with amp r Do not interpret the at the end of a line as line continuation s Put the input line into the history file un Read the input from file descriptor n Example echo What is your name c read name
319. trackable although they are aliasable This option is turned on automatically for non interactive shells See Chapter 23 for details on the set command If the PATH variable is changed while you are in the shell either interactively or by rerunning your profile or kshrc then the tracked alias definitions set are lost until you execute each command again Exporting Aliases for Korn Shell only Exporting aliases works in much the same way as exporting variables with export But ksh will only export an alias to another shell that is not a separate invocation of ksh an exported alias will survive a fork 2 but not an exec 2 Exported aliases are available to subshells for example prog and to shell scripts that do not start with bin Part Ill POSIX and Korn Shell Aliasing 18 3 FINAL TRIM SIZE 7 5 in x 9 0 in 18 You export aliases interactively or from within your profile or kshrc To do so type or add to the appropriate file alias x who who sort Then when you type alias or alias x who who sort is shown Default Aliases The shell provides several default aliases that are always set by the shell To see a listing of those defaults and any other aliases currently defined type alias As long as this command is typed by itself with nothing following it provides a list of the current shell aliases Something similar to the following is returned alias false let 0 func
320. trule append rcs u Part IV Key Shell Customizing the Key Shell 27 25 FINAL TRIM SIZE 7 5 in x 9 0 in option set_tag disable all string lt tag gt editrule append rcs N amp trim argument amp required Enter the name of the symbolic tag to set option delete_tag disable all 27 string lt tag gt editrule append rcs N amp argument required Enter the name of the symbolic tag to delete string lt files gt disabled disable 1 editrule append argument required Enter the name of the RCS or working file s 27 26 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Index A adding help text to softkeys 27 20 hint text to softkeys 27 19 invisible softkeys 26 19 required text to softkeys 27 19 text to softkeys 27 20 visible softkeys 26 16 attributes of softkeys 27 6 backup softkeys 27 23 Bourne shell 26 1 c cancelling a command 26 14 changing global configuration options 26 24 status line 26 26 characteristics terminal 26 3 child nodes 27 4 COLUMNS 26 1 26 29 command line editing 26 12 commands cancelling 26 14 editing 26 12 entering 26 4 26 8 formatting 27 21 HP UX 26 11 invisible softkeys 26 10 26 19 visible softkeys 26 9 26 18 components of softkey nodes 27 3 Part IV Key Shell FINAL TRIM SIZE concepts Key Shell 27 1 configuring Key Shell 26 15
321. ult POSIX Shell Korn Shell and Bourne Shell prompt is a dollar sign The default C Shell prompt is Once you have typed a command line the shell interprets and executes it For example echo Welcome to Korn Shell Welcome to Korn Shell This example shows the echo command followed by its argument a string of text that is to be displayed on echoed to the terminal Output from the echo command appears on the next line Welcome to Korn Shell Note that echo is a shell built in and so no process is spawned However bin echo is a utility and will spawn a process and assign it a process id process identifier The software for each shell is shipped with HP UX and resides on your HP UX file system m The POSIX Shell resides in bin posix sh m The Korn Shell software resides under the directory bin in the file ksh that is in bin ksh a C Shell resides in bin csh Bourne Shell resides in bin sh The rest of this tutorial deals mainly with the POSIX and Korn Shells If you do not understand the login process or the file directory system or if you have questions about shell structure or interaction with the shell read about these topics in Using HP UX 16 2 Starting Stopping the Shell Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Invoking the Shell Initially when you log into an HP UX system a default shell POSIX is spawned for you To determine if sh is your shell type ech
322. umber of the last background command executed So to wait for that background process to terminate you would use wait wait without parameters waits for all child processes to terminate Part I Bourne Shell Detailed Reference 8 15 FINAL TRIM SIZE 7 5 in x 9 0 in Return Values When a function or a command terminates it sets a flag indicating the status of the termination In other words if the function or command was successful in executing it returns a value indicating its success The values or error codes normally used are listed in the exit section These values are only conventions shell scripts normally use these conventions but programs in general do not When you execute a shell command incorrectly you usually get an error message What usually happens is the shell command returns an error code If the error code is say 2 you will receive a message indicating a syntax error has occurred You can return error codes from your shell programs and functions in two ways The exit statement can return any value you specify by using the following format exit n where n can be an integer from 0 to 255 You can return error codes from functions by using the return statement return n To check the return value of the last command you executed you can use a parameter called 7 8 16 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in Parameters Set by the Shell You can access s
323. ument to trap 19 power fail Trappable 20 virtual timer alarm Trappable 21 profiling timer alarm Trappable 22 reserved Cannot be used as argument to trap 23 window change or mouse signal Cannot be used as argument to trap Hash The format for hash is hash r name where name is a list of command names 8 12 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in The hash command makes searching for a command faster Usually the shell will look in your search path indicated in the shell parameter PATH and go through each directory searching for the first occurrence of the command hash will place the command in a table and include a pointer to the directory in which it resides Thus when you call the command the hash table is first checked If the command is in the hash table it will be able to go directly to the directory instead of through all of the directories in the search path If you wish to delete the remembered locations in the hash table include the r option The default for hash no options or parameters is to print a listing of all commands used since login The list includes two columns hits which are the number of times the command has been invoked by the shell process and cost which is the measure of work required to locate a command in the search path The default hash command is used more for information to see how the performance of the hash table is compared to
324. up we get the following for an interactive shell 1 1 0 _ 1 0 1 0 FILE O HOME envfile And for a non interactive shell _ 1 50 _ _ 1 O 0 1 FILE Part Ill POSIX and Korn Shell Advanced Concepts 23 3 FINAL TRIM SIZE 7 5 in x 9 0 in 23 Co Processes The Korn Shell provides a mechanism to spawn a child process connected by a pipe to the parent shell The standard input and output of the spawned command can be written to and read from the parent shell Placing the amp metacharacter after the command to be executed creates a special pipe where you can use the print p command to write the standard input of the spawned command process and the read p command to read from the output of the process See Chapter 21 for details on the print and read commands These two way pipes allow shell scripts to pass data out through a pipeline process that data with a coprocess and bring data back through the pipeline for further use by the script without having to use temporary files to store the input or output data For example suppose you have a file 2waypipe containing this script pis3 14159 bs amp echo Please enter valuei and value2 c read value1 value2 print p value1l value2 add them read p sum print p sum pi read p result The answer is result 23 4 Advanced Concepts Part Ill POSIX and Korn Shell FINAL TRIM SIZE
325. utes them as indicated in the order indicated if they exist etc csh login If C Shell is your login shell and this file exists it is executed cshrc If this file exists in your home login directory it is executed every time C Shell starts whether at login or when C Shell is spawned from another shell login If C Shell is your login shell and this file exists in your home directory it is executed While none of these files is required if present they provide a convenient means for customizing the shell environment to fit your needs Part Il C Shell Preparing to Use the Shell 10 5 FINAL TRIM SIZE 7 5 in x 9 0 in 10 Setting Environment and Shell Variables Two kinds of variables can be set in the cshrc and login files Environment variables These variables are global used by the login shell process and any processes spawned by the shell process They are usually represented by uppercase letters Shell variables Shell variables are local used by the login shell process only and are not inherited by spawned processes They are usually represented by lowercase letters Environment variables are usually defined by using the setenv command while shell variables are typically defined by the set command However three of the most commonly used environment variables USER TERM and PATH are automatically imported to and exported from three corresponding variables user term and path Thus if you execute
326. value of this parameter ends in emacs gmacs or vi then the corresponding set o option is turned on See the set command in Chapter 23 If this parameter is set to a script s name when a shell is invoked the script is executed by the new shell prior to going interactive Specifies the name of the editor to use when the fc command is executed and the fc command does not designate an editor Internal Field Separators usually space tab and new line which are used to separate command words during command or parameter substitution and when using the read command 16 10 Starting Stopping the Shell Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Shell Parameters continued Parameter Definition HISTFILE This is set to the path name of the file to be used to store the command history The default is sh_history HISTSIZE This is set to the number of saved commands accessible by the shell The default size is 128 HOME The default for the cd command which is your home directory LINES When this is set to a value that value determines the column length for printing lists created by the select command MAIL If this parameter is set to the name of a mail file and the MAILPATH parameter is not set then the shell tells you mail has arrived in the named file MAILCHECK This parameter specifies how often in seconds the shell checks for the arrival of new mail The default is 600 seconds MAILPA
327. variable x and then increments and prints out the value until it equals 5 and you exit the loop x 0 while x 5 gt do gt let x x 1 echo x done 21 12 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in Using the break Statement This command exits loops created by the keywords for while until or select The syntax is break n If n is specified it breaks out of n nested loops The following script checks the list of files x y z none for executable files and prints the first executable file it encounters If none are executable file is left set to none but it is not printed for file in x y z none gt do gt if x file then echo file break gt gt gt fi gt done Part Ill POSIX and Korn Shell Basic Shell Programming 21 13 FINAL TRIM SIZE 7 5 in x 9 0 in 21 21 Using the continue Statement This command skips any lines following it in a for while until or select loop until the next iteration of the loop Syntax is continue n If n is specified then resume execution starting at the nth enclosing loop This next script checks for all executable files If the file is executable the continue statement skips both following echo statements and starts another loop If the file is not executable the script prints that it is not executable If the file is executable nothing is printed for file inx yz
328. vely to i since the in clause was omitted If the positional parameters are file names the script will sort the file and place the result in a file having the same name as the unsorted file with srt appended to it It will then get the next positional parameter until all have been accessed You can also use pattern matching to specify the word list Pattern matching is discussed in the section entitled Case and in the section entitled Using Shell Expansions 6 2 Advanced Programming Part I Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in While The while construct repeatedly executes a list of commands in the following format while command list1 do command list2 done All of the commands in command list1 are executed If the last command in the list is successful indicated by an exit status of 0 from the command then the commands in command list2 are executed Then we loop back to execute command list1 until the last command in the list is unsuccessful and then the while loop terminates while r 1 do cat 1 gt gt composite shift done This example tests the positional parameter to see if it exists and is a readable file If it is it appends the contents of the file to the composite file shifts the positional parameters what was 2 is now 1 and tests the new file When the file is not readable or there are no more positional parameter values 1 is null the while loop is te
329. verything after the is a comment Data Input and Output Programming inevitably requires inputting and outputting of data The Korn Shell provides the echo command and the print command for outputting and the read command and positional parameter substitution for inputting Reading Input Data There are several ways of passing data into a shell script One way is by passing arguments to the script through positional parameters the other way is by using the read command A third way is for the script to run some command or program that reads stderr or a named file Positional parameters have already been described in detail in Chapter 19 Therefore the following discussion focuses mainly on the read command The read command provides the ability to read input during the execution of a script The read syntax for POSIX Shell is read r name tae 21 2 Basic Shell Programming Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in The read syntax for Korn Shell is read prsu n name prompt name Lee where in each case the command reads a line and places each white space separated word into a name The rest of the line goes into the last name For 21 the Korn Shell if names are not specified the line is read into the shell REPLY variable see select under Conditional Statements If prompt is set the user is prompted interactively with prompt Option definitions are p Read fro
330. what HP UX command or option is associated with each part of the softkey command where the HP UX command or option belongs in the translated command line and where any user typed text belongs 27 8 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in The HP UX command that keysh constructs can be thought of as a list of words Each word corresponds to a part of the HP UX command and has an index according to its position in the command line As keysh constructs the HP UX command it uses the position of other words in the command line to determine where to place options or text The completed list of words each separated by a space is then passed to the Korn Shell for execution The following example shows a softkey command its translation to HP UX and the corresponding word list Remove files interactively c Softkey command 27 rm i c HP UX translation word 0 word 1 word 2 Corresponding word list elements Editrules The editrules associated with softkey nodes contain instructions for manipulating the words in the word list Editrules can be used to add delete or modify words When an editrule is invoked the following constants are set m last is defined to be the index of the last word in the word list 2 in the preceding example m next is defined to be the index of the word that would be next in the word list 3 in the preceding example m argument is defined
331. when locating subdirectory arguments used with pushd cd and chdir commands Boolean noclobber Suppose you use the following command sequence to send keyboard input to a file called newfile cat gt newfile If newfile exists before this command sequence is executed the old copy of newfile will be overwritten and thus destroyed To prevent accidental 13 2 Shell Variables Part Il C Shell FINAL TRIM SIZE 7 5 in x 9 0 in 13 overwriting of a file containing valuable information set the boolean noclobber variable so that C Shell cannot overwrite files by including the command line set noclobber in your login file To demonstrate its effectiveness type the following C Shell commands cat gt newfile This is a test message EOT set noclobber cat gt newfile newfile File Exists h When you try to cat to an existing file with noclobber set the system tells you the File Exists and aborts the command To override the noclobber use the exclamation point metacharacter For example cat gt newfile newfile File Exists hcat gt newfile This is an override test EOT h Boolean notify If the notify variable is set you are immediately notified when a background process finishes If unset notification messages related to background process completion occur with the next presentation of the C Shell prompt Use the set command to set notify Part Il C Shell Shell Variables 13 3 FINAL TRIM S
332. wish to include You should note the following things concerning Bourne Shell functions m When calling a function no parentheses are used when defining a function parentheses are necessary m When specifying parameters in a function call be aware that the positional parameters 1 2 for the entire shell program will be reset to these parameters and the original values will be lost Input Output The common redirection symbols can be used in shell programs gt for redirecting output to a file gt gt for appending output to a file lt for redirecting input to a command from a file In addition are these redirection conventions lt lt word 8 4 Detailed Reference Part Bourne Shell FINAL TRIM SIZE 7 5 in x 9 0 in This redirection construct called a here document causes all lines after this one and up to a line consisting only of word to be used as input data Let s look at a sample section from a script file cat lt lt marker These words are to be printed with the cat command until the line with marker is found marker echo End of text The text down to but not including marker will be printed on the screen when this script is run Then the echo command is executed giving an output of These words are to be printed with the cat command until the line with marker is found End of text Be sure to include quotes in word if the line contains special char
333. word in the word list begins with a dash string is appended to that word Otherwise a dash is appended as a new word in the word list immediately after the last word and string is appended to that dash For example if you had already selected an option that appended c to the command this editrule would add only the b to form cb option without_tabs editrule dash b If Statement The if edit statement allows you to specify a condition for executing an edit statement The general syntax of the if statement is as follows Note that the else is optional if condition edit statement else edit statement If condition is true evaluates non zero the first block of edit statements is executed Otherwise the second block of edit statements if it exists is executed Part IV Key Shell Customizing the Key Shell 27 13 FINAL TRIM SIZE 7 5 in x 9 0 in 27 27 In the following example from the 1s command the editrule checks for an 1 in the command line If 1 is not already in the command line a 1 is added Then a d is added option dir_info_only disable all editrule if 1 dash 1 dash d Blanks To strip leading and trailing blanks from a user typed string use the trim function as follows trim string In the following example you are required to enter a number or select another option thru If you enter a number followed by a blank space the trim function strips
334. y keysh test disable all editrule append keysh test softkey keysh doc disable all editrule append keysh doc softkey demo disable all editrule append demo softkey tmp disable all editrule append tmp string lt dir gt disable all editrule append argument hint Enter the name of the directory to move to 27 24 Customizing the Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in This example shows a custom softkey for RCS source control The options allow you to perform such tasks as checking files into and out of RCS control reviewing different versions of a source controlled file and deleting locks on files For more information about RCS source control refer to res 1 softkey Source_control option check_in disable 5 enable all editrule append ci u required Select a source control function 27 option check_out disable 4 enable all editrule append co 1 option review_revision disable 3 enable all string lt rev gt editrule append co p amp argument required Enter the number of the revision to review option show_log disable 2 enable all editrule append rlog option show_changes disable 1 enable all editrule append rcsdiff option admin disable O enable all option set_lock disable all editrule append rcs 1 required Select an administration function option delete_lock disable all edi
335. your profile file export KEYSH Hi there Return 26 28 Getting Started With Key Shell Part IV Key Shell FINAL TRIM SIZE 7 5 in x 9 0 in Table 26 7 Key Shell Variables Variable Description COLUMNS Defines the width of the edit window if different than the terminfo 4 default KEYBEL Specifies the character sequence to be used for keysh s bell The default is CTRL G ASCII 007 To disable the bell set this variable to an empty string KEYENV Specifies an alternate keysh configuration file The default is 26 HOME keyshrc KEYESC Specifies the maximum number of milliseconds allowed between characters that are part of a terminal escape sequence The default is 350 KEYKSH If set causes keysh to mimic the behavior of the Korn Shell The softkeys and status line are not displayed This mode is useful over slow modem lines KEYLOC If set specifies that keysh should leave the terminal keypad in local mode while commands are being entered This mimics the behavior of the Korn Shell KEYMORE If set specifies that keysh should return to the first bank of softkeys after executing a command rather than remaining on the bank where the command was located KEYPS1 If set specifies that keysh should not reset the initial values of PS1 PS2 and PS3 KEYSH Lets you specify arbitrary text to include in the keysh status line KEYSIM If set specifies that key
336. ystem file structure Each directory in the path is separated with a colon When a command is executed the shell looks in each of the directories specified in PATH to find the command When you type ksh the shell checks usr bin first and then usr lib and so on down the PATH line until it finds the directory where the ksh program resides In this instance ksh is found in the third directory bin 16 6 Starting Stopping the Shell Part Ill POSIX and Korn Shell FINAL TRIM SIZE 7 5 in x 9 0 in m MAIL names the file in which your mail is delivered The if statement checks whether new mail has arrived and notifies you m HOME sets your home directory to the directory where the shell places you when you execute the cd change directory command with no options This is usually set automatically by the shell at login 16 m EDITOR sets your default editor to the vi editor Then whenever you need to perform in line command changes you immediately enter vi mode If you have never used the vi editor see Using HP UX or The Ultimate Guide to the vi and ex Text Editors a ENV is normally assigned to be kshrc to be executed whenever a shell is spawned For example ENV kshrce In this example ENV is directly set to Ashre in your home directory The specifies your HOME directory see Tilde Substitution in Chapter 19 for more details If your Ashre is very long and involved spawning a new shell can take awhile The ENV

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