Wiley Mac OS X Snow Leopard All-in-One For Dummies
Contents
1. Book VIII Chapter 1 Weauag syn XINN PUY 644 Figure 1 2 Draga file from a Finder window into Terminal to display its path UNIX Commands 101 Documents 2 S Quick Look Action m7 0 m Back Vew Search DEVICES Ludwig Z wolfgang E mother B osk Johana About Stacks pdf Antonio SHARED E blackdragen AOE Terminal bash 80x24 Mork Cherberss Mac mark Users work Decunents about Stacks odf s W doliserver PLACES E Desktop mark A Applications G SEARCH FOR Today Yesterday D Past Week 1 of 1 selected 49 78 caj You can even use the mouse while entering commands in the Terminal Click and drag your mouse over text to select it From there you can copy to the Clipboard as you might expect with any other application UNIX Commands 101 To use the command line effectively familiarize yourself with the commands that are available to you After all how can you use a tool without knowing what it can do Despite having to memorize a few commands UNIX usually makes it easy on you by abbreviating commands by following a standard grammar so to speak and by providing you with extensive documentation for each command Anatomy of a UNIX command UNIX commands can perform many amazing feats Despite their vast abilities all commands follow a similar structure command lt optional flag s gt lt optional operand s gt The simplest form of2. time you can save them to a text file and execute the entire file with only one command Now that s power right up there with the dynamic duo of AppleScript and Automator Of course you probably don t like doing housekeeping tasks while you re busy on other things so schedule that list of commands to run in the middle of the night while you re fast asleep The command line lets you do that too Note that automation of UNIX commands is totally separate from automation of Mac OS X applications with AppleScript and Automator which I cover in Book VIII Chapter 2 Remote control So Mark the command line is the cat s meow for efficiently accessing and working with files on my Mac and I can use it to automate many operations Anything else I m glad you asked By using the command line you can also send commands to another computer anywhere in the world as long as you know the right login and password After you log into another computer you can use the same commands for the remote computer UNIX was created with multiple users in mind Because computers used to be expensive and honking huge machines to boot UNIX was designed so that multiple users could remotely use the same machine simultaneously In fact if Mac OS X is your first encounter with UNIX you might be surprised to know that many UNIX beginners of the past weren t even in the same room building state or even country as the computer that they wer
3. 18 29 646K 184K 1132K 74 494 bash 14 19 240K 180K 888K 74 493 login 16 55 240K 224K 716K 751 466 Terninal 104 123 2832K 11M 8076K 2851 391 Grab 193 251 15M 23 23N 327M 191 iTunes 218 45 1 15N 33N 327M 188 mdworker 72 83 1096K 2688K 3004K 126M 163 launchd 24 25 112K 276K 436K 74M 152 smbd 8 55 64K 3104K 316K 791 151 winbindd 156 winbindd 149 winbindd it 46 232K 1752K 1188K 7M 8 37 132K 1743K 636K 7M 14 37 128K 1743K 1292K 77M 147 cupsd 32 30 780K 224K 1552K 75 146 iChatAgent 78 56 1236K 2580K 4176K 216M 141 smbd 17 55 200K 3104K 1972K 791 146 ocspd 18 21 432K 183K 1004K 74 136 usbnuxd 134 iTunesHelp 112 ATSServer 21 27 268K 186K 596K 751 59 52 528K 3108K 2440K 219 84 70 816K 2352K 2612K 118M 411 Finder 431 33 1M 28m 34M 339M 116 SystenUISe 261 239 5132K 7392K 16M 284r 169 Dock 131 195 2888K 49M 6752K 293M 108 pboard 15 23 184K 186K 508K 75M 105 UserEvents i 51 596K 240K 1944K 75M 184 Spotlight 59 58 1248K 3764K 4076K 226M 96 launchd 133 26 226K 286K 512K 74 81 coreaudiod 47 WindouServ 161 79 1240K 972K 2180K 77M 178 631 10M 26M 34M 2881 SRRRRRRRLERRRERRRERRReRRREs PN z SNROPNEMNCOANNNEBRNN EEE EO DOW a a Besides listing the names of the various processes currently in use top tells you how much of your CPU is being devoted to each process This lets you know what process is currently hogging all your computing power Sometimes a process stalls effectively freezing that action By using the top c
4. enclose the folder s name in quotation marks like this cd My Picture Folder Read more about using quotation marks in your commands in the upcoming section Command line gotchas To return to your Home folder in this example enter a modified version of the cd command cd This causes your Mac to move back up the folder hierarchy one folder to your Home directory By using these three simple commands 1s cd foldername and cd you can traverse your entire hard drive After you successfully enter a command you can recall it by pressing the up arrow key Press the up arrow key again to see the command prior to that and so forth This is an extremely useful trick for retyping extra long file paths Using the skills you already have Just because the Terminal is text based doesn t mean that it doesn t act like a good Macintosh citizen All the usual Mac features that you know and love are there for you to use Copy and Paste functions work as you might expect but only at the prompt position Drag and drop is also at your disposal After you play around with the Terminal for a while you ll find yourself bored to tears typing the long paths that represent the files on your hard drive To automatically enter the path of a file or folder to a command simply drag it to the active Terminal window as shown in Figure 1 2 The file s full path instantly appears at the location of your cursor Thanks Apple
5. the keyboard Although mouse skills can be applied to UNIX you ll generally find performing UNIX functions faster and easier with the keyboard 63 8 Why Use the Keyboard UNIX keyboarding is fast Why on Earth would any red blooded Macintosh owner want to leave the comfort of the mouse to use a keyboard After all the graphical user interface is what made the Macintosh great in the first place With the Finder you can navigate and manage the various files on your hard drive with a few clicks This sounds simple enough but for some tasks using the keyboard can be just as fast if not faster Suppose for example that you need to copy a file from somewhere on your hard drive to somewhere else on that same drive To do so with the Finder you must first open a Finder window by clicking the Finder icon in the Dock or by double clicking a drive icon on your Desktop Then by using a succession of mouse clicks you navigate to where the file that you wish to copy resides Next you might open another Finder window and navigate to the folder where you wish to copy the file Note that opening the second Finder window requires pressing 86 N clicking the Finder icon in the Dock doesn t open a second Finder window Finally you duplicate the original file and drag that copy to its intended destination Comparatively by using the keyboard and the power of UNIX you can accomplish the same task with a one line command For some tasks the mo
6. 650 Working with Files MBER KV A close cousin to the cp copy command is the mv move command As you can probably guess the mv command moves a folder or file from one location to another I told you that all this character based stuff would start to make sense didn t I To demonstrate this command moves MyDocument from the Desktop folder to the current user s Home folder mv Desktop MyDocument MyDocument Ah but here s the hidden surprise The mv command also functions as a rename command For instance to rename a file MyDocument on the Desktop to MyNewDocument do this mv Desktop MyDocument Desktop MyNewDocument In this case you can see that the mv command is really copying the original file to the destination and then deleting the original Because both folders in this example reside in the same folder Desktop it appears as though the mv command has renamed the file Again like the cp command the mv command requires that you have proper permissions for the action that you want to perform Use the sudo command to perform any commands that your current user as displayed in the prompt isn t allowed to execute On UNIX systems not all users are necessarily equal Some users can perform functions that others can t This is handy for keeping your child s mitts off important files on your computer It also creates a hurdle should you choose to work on files while using your child s restricted
7. AGON markchambers It s easy to return to your Home directory by following this sequence WHITEDRAGON markchambers cd Users WHITEDRAGON Users markchambers S cd markchambers WHITEDRAGON markchamberssS Here s a faster way Instead of moving through each successive folder until you reach your intended destination you can specify the path by using just one cd command WHITEDRAGON markchambers cd Users markchambers WHITEDRAGON markchamberss Of course the Home directory is a special folder in that you can also navigate there by simply entering cd but the main point here is that you can navigate directly to specific folders by using that folder s path in conjunction with the cd command MBER et amp avr Working with Files 649 Furthermore when you navigate your hard drive by using paths you can jump directly to your desired destination from any place When you enter cd it is in relation to your current position whereas entering cd Users markchambers will always take you to the same directory regardless of your starting point Copying moving renaming and deleting files After you re comfortable with moving around the hierarchy of your hard drive it s a cinch to copy move and rename files and folders To copy files from the command line use the cp command Because using the cp command will copy a file from one place to another it requires two operands first the sourc
8. Chapter 1 And UNIX Lurks Geneath In This Chapter 1 Why use UNIX Doing things with the keyboard Introducing UNIX commands Creating text files v Exploring deep inside Mac OS X A s I mention in the first chapter of the book at the beginning of our Snow Leopard odyssey UNIX lurks deep beneath the shiny Aqua exterior of Mac OS X UNIX is a tried and true operating system that s been around for decades since the days when mainframe computers were king If you don t believe that it s a powerful and popular operating system consider that over half of all Web servers on the Internet use some variety of UNIX as their operating system of choice Besides being battle tested and having a long history UNIX offers some fantastic features Unlike the graphical world of Mac OS X the keyboard plays an integral role while you re using a UNIX based operating system Because UNIX is text based you ll find that it s evolved a large set of useful keyboard driven commands that can perform powerful feats that a mouse user just can t easily equal This chapter examines the role of the keyboard in UNIX operating systems and describes how to execute standard file system commands You also discover how to use Apple s additional set of commands and install your own commands and simple programs from the Internet Why Use the Keyboard To begin benefiting from the UNIX underpinnings of Mac OS X get used to doing things with
9. a UNIX command is the command itself For a basic discussion on UNIX commands such as 1s see the earlier section A few commands to get started You can expand your use of the 1s command by appending various flags which are settings that enable or disable optional features for the command Most flags are preceded by a dash and always follow the command For instance you can display the contents of a directory as a column of names by tacking on a 1 flag to the 1s command ls 1 MBER S MBER we amp ar UNIX Commands 101 645 Besides flags UNIX commands sometimes also have operands An operand is something that is acted upon For example instead of just entering the 1s command which lists the current directory you can add an operand to list a specific directory ls Documents myProject The tilde denotes the user s Home directory Sometimes a command can take multiple operands as is the case when you copy a file The two operands represent the source file and the destination of the file that you want to copy separated by a space The following example copies a text file from the Documents folder to the Desktop folder by using the cp command short for copy cp Documents MyDocument Desktop MyDocument You can also combine flags and operands in the same command This example displays the contents of a specific folder in list format ls 1 Documents myProject Command line gotchas In earlier
10. e and then the destination For instance to copy a file from your Home folder to your Documents folder use the cp command like this cp MyDocument Desktop MyDocument Keep in mind that when you copy files you must have proper permissions to do so Here s what happens when I try to copy a file from my Desktop to another user s Desktop strangely named fuadramses WHITEDRAGON markchambers cp Desktop MyDocument Users fuadramses Desktop MyDocument Denied Thwarted Refused cp Users fuadramses Desktop MyDocument Permission denied If you can t copy to the destination that you desire you need to precede the cp command with sudo Using the sudo command allows you to perform functions as another user The idea here is that the other user whom you re emulating has the necessary privileges to execute the desired copy operation When you execute the command the command line asks you for a password If you don t know what the password is you probably shouldn t be using sudo Your computer s administrator should have given you an appropriate password to use After you enter the correct password the command executes as desired In case you re curious sudo stands for set user and do It sets the user to the one that you specify and performs the command that follows the username sudo cp Desktop MyDocument Users fuadramses Desktop MyDocument Password Book VIII Chapter 1 Weauag syn XINN PUY
11. e used to perform that command Refer to the bottom of Figure 1 7 The A character is shorthand for the Control key on your keyboard Thus to save a file press A O This flies in the face of standard Mac keyboard conventions where the letter O is traditionally used to mean Open After pressing the Control O sequence pico prompts you for a filename As with most UNIX files you re permitted to enter a simple filename here or a full path to a file For this example save the file to your Documents folder naming it MyPicoDocument After you ve completed and saved the document pressing Control X will transport you away from Planet Pico and back to the command line Networking with the Terminal Because UNIX isn t a new phenomenon it has many useful networking abilities built into it In fact UNIX was instrumental in creating much of what we now take for granted e mail the Internet and the World Wide Web Thus you ll be happy to know that you can communicate over networks with the Terminal in practically any manner that you can dream of and then some WWW and FTP If you ve used the Internet for any time you re probably familiar with the various means to transport data over a network From FTP short for File Transfer Protocol and Telnet to e mail and the Web UNIX can handle it all In fact UNIX has a command for each of these functions and many more that have passed into historical obscurity Rather than use each
12. e using Not only can you work with a computer that s in a different physical location but it s also very fast to do so Instead of the bandwidth hog that is the Internet the command line is lean and mean This permits you to use a remote computer nearly as fast as if it were sitting on the desk in front of you This is a great advantage for road warriors who need to tweak a Web or an e mail server from a continent away Uncovering the Terminal 64 1 Uncovering the Terminal Figure 1 1 Find the Terminal application in your Utilities folder ar The best way to find out how to use command line is to jump right in Mac OS X comes stocked with an application named Terminal The Terminal application is where you enter commands in the command line It s located in the Utilities folder within the Applications folder on your hard drive choose Applications Utilities Double click the icon as shown in Figure 1 1 to launch Terminal lane J Utilities kalj ry Q tek ew Quick Look Action Search Ludwig L wolfgang E Mother El isk Johann Antonio snaro D on E blackdragon E deliserver PLACES E Desktop amp mark A Applications A Date Mocfied Orania Keychain Access January 29 2009 9 04 PM 12M EARCH FOR amp Migration Assistant January 28 2009 8 29 PM 12M Today Network Udlity January 27 2009 3 21 PM 1 26 Yesterday Podcast Capture January 18 2009 2 06 AM 4 8 Past Week i RAID U
13. erchangeable Help is on the way By now you might be wondering how a computer techno wizard is supposed to keep all these commands straight Fortunately you can find generous documentation for nearly every command available to you To access this built in help use the man command Using the man command shorthand for manual will display a help file for any command that it knows about For example to read the available help information for the 1s command simply type man ls at the prompt Figure 1 3 illustrates the result eoe Terminal grotty 125x39 Ls t gt B50 Gereral Cowrends Manuel Ls 1 a WE is list directory contents SYMPSIS le ABCFGHLPRSTWbodefghik lanoparstuwxi Cile 1 ON och operand that naves a tila of a tyga other taon directory d associated inforration For each cperand thet mmes c fi naws of Tiles containad within thot directory as wall ce an recwested DESCRIP Fi tory ls displays the ated information If no operaris ore given the of the current directory ore dis 1f were than one oparand is given ron directory opercres are displayed first directory aad ron directory convenes are sorted 329a rately ond in lexicograghical order he following options are ova lable a Display extended ottribute keys avd sizes 4 The auverte digit vone Force output to be one entry per line This 1s the defcult when oit put is net to a terminal A List all entries e
14. individual command to send and retrieve data with the Terminal Apple has conveniently MBER KV amp UNIX Programs That Come in Handy 657 provided a command that can handle them all cur1 The curl command is competent at all the standard network protocols To see it in action pass a Web address or URL to The Enlightened to the curl command curl http www mlcbooks com The result is that you see the HyperText Markup Language HTML page that s located at www mlcbooks com Because this isn t particularly useful for most people it s not very easy to read you need to add the letter o asa flag This specifies where you would like to save this file upon download To save the HTML page to your Home directory add the o flag and a path to the destination file Don t forget to precede all flags with a hyphen For this example it would be o curl o mlcbooks html http www mlcbooks com If you now perform an 1s command you see that cur1 has in fact downloaded the HTML found at www mlcbooks com and saved it to a file named mlcbooks htm1 in your Home directory The beauty of cur is that it does much more than just retrieve Web pages It s equally comfortable with FTP transfers FTP is used to download or receive files from a server as well as upload or send them Like the previous HyperText Transfer Protocol HTTP examples you only have to provide an FTP address in Uniform Resource Locator URL format and cu
15. l bash 85x38 AS gl WhiteDragon morkchombers cal 1970 1970 January February March SHu Emh FS SH HF S S Am YME S SU r r gi A Se Te a Ales e a a OR e 45678 9146 8 91611121314 83 91611 12 13 14 11 12 13 14 15 16 17 15 16 17 18 19 20 21 15 16 17 18 19 26 21 16 19 20 21 22 23 24 22 23 24 25 26 27 28 22 23 24 25 26 27 26 25 26 27 28 29 38 31 29 39 31 April Nay dune Stu th FS SMTu Th FS SNM WHF S i 2 34 12 i235 4 5 6 66789111 3456789 7 8 916011 1213 12 13 14 15 161718 1611 12 13 14 15 16 14 15 16 17 18 19 20 19 26 21 22 23 24 25 17 18 19 20 21 22 23 21 22 23 24 25 26 27 26 27 28 29 30 24 25 26 27 26 29 30 28 29 3 31 duly August September Stu t FS SMTu Th FS SNTU WHF S Life oe 4 1 123 4 5 6 678910011 2345678 678 91811 22 12 13 1415 161718 9161112131445 13 14 15 16 17 18 19 19 26 21 22 23 24 25 16 17 18 19 26 21 22 20 21 22 23 24 25 26 26 27 26 29 30 31 23 24 25 26 27 28 29 27 26 29 3 3 31 October Novenber December SHu th FS SNU th F S SNU WTF S e Ss E Si 4 EF i 2 34 5 45678910 8 91011121314 6 7 91811 12 11 12 13 14 15 16 17 15 16 17 18 19 26 21 13 14 15 16 17 18 19 18 19 26 21 22 23 24 22 23 24 25 26 27 28 20 21 22 23 24 25 26 25 26 27 28 29 30 31 29 39 27 25 29 WA v WhiteDragon norkchonbers f Append a month number and a year number to display the calendar for that month For example to view a calendar for April 2010 type cal 04 2010 Use the m flag to specify the current year as in cal m 08 f
16. ls for finding files or even stringing together commands Finding files The command line gives you a number of ways to search for files on your hard drive The two most commonly used commands are find and locate To use find specify a starting point for the search followed by the name of the file or folder that you want to find For example to find the Fonts folder that belongs to your user enter the command like this find name Fonts You should see at least one result of the find command Users markchambers Library Fonts One great feature of the find command is that you can look for a file or folder in more than one location Suppose you want to find a file named MyDocument that you know resides either in your Documents folder or on your Desktop For this kind of search use the find command like this find Documents Desktop name MyDocument In this example you are telling the find command which folders it should search when looking for the file named MyDocument Using pipes Nearly all UNIX commands can take on greater abilities by using a construct called the pipe A pipe is represented by that funny little vertical line that shows up when you press Shift The pipe routes data from one command to another one that follows for example many UNIX commands produce large amounts of information that can t all fit on one page You might have noticed this behavior when you used the locate command Joining tw
17. mage tif Useful Commands ar Figure 1 4 Type cal to view a calendar for the current month Manipulating files and viewing folder content is fun but the command line is capable of so much more Now I focus your attention on some of the other useful tasks that you can perform with the command line Mac OS X comes stocked with a full set of useful commands You can discover what commands are installed by viewing the files in usr bin Type cd usr bin to navigate there Calendar One of my favorite command line functions is the cal command which displays a calendar in text form Simply entering cal at the prompt displays a calendar for the current month as shown in Figure 1 4 m a0ea Terminal bash 80x24 Last login Man Jan 8 19 19 22 on ttypi okie fenokies macbook pro 15 mark cal Sorwary 2087 Su Mo Tu We Th Fr Sa 123456 ts 7 8 9 16 14 12 13 14 15 16 17 18 19 26 24 2 21 22 23 2 28 29 38 34 okie fenokies macbock pro 15 nark J Book VIII Chapter 1 Weauag Hun XINN Puy 652 Useful Commands Figure 1 5 Type cal followed by a year to view the 12 months of that year ar Append a number to the cal command to display a 12 month calendar for that year The number that follows the cal command is the year for which you d like to see a calendar For example to view a calendar for 1970 type cal 1970 The result appears in Figure 1 5 i gt e208 Termina
18. network communications One of the niftier ones is the Dictionary protocol With it you can look up words from any server that understands the protocol Suppose for example that you want to know the meaning of the term DVD Enter the following command to find out curl dict dict org d DVD With curl1 Dictionary and your Dictionary Dashboard widget on the same Macintosh you might never use a real paper dictionary again
19. o commands or functions together with the pipe command is piping To tame the screens full of text pipe the find function to the less command The less command provides data one page at a time UNIX Programs That Come in Handy find name Fonts less 655 When the results fill up one page the data stops and waits for you to press any key except the Q key to continue When you reach the end of the results press Q to quit and return to a command line prompt UNIX Programs That Come in Handy As a Macintosh user you might be surprised to know that many applications on your hard drive don t reside in one of the typical Applications folders of Mac OS X These applications in fact don t have any graphical user interface like what you re accustomed to They re accessible only from the command line The remainder of this chapter covers some of these applications Text editors UNIX has many text editing applications for use at the command line Some of the more popular ones include pico vi and emacs Each of these text editors has its pros and cons and say thanks to the thorough folks at Apple because all three are included with Snow Leopard For my examples here however I use pico because it s simple to use and sufficient for our needs Creating a new document To create a text file by using pico simply type pico at the command line The result looks like Figure 1 7 200 Ua PICOCtm gt 2 5 pic
20. o ttyp1 Figure 1 7 The pico program is a full strength text editor right from the command line mA Get Help Writedut ay Read File Prev Pg wy Exit Justify gg Where is Next Pg Modified ae Cut Text Cur Pos ee Uncut Text To Spell Book VIII Chapter 1 Weauag sin XINN PUY 656 UNIX Programs That Come in Handy EMBER amp This is the rough and tumble world of UNIX which preceded the Macintosh by many years Perhaps this will also help you to appreciate why the Macintosh was so revolutionary when it was introduced You can just hear the designers crowing We ll call this a menu Yeah that s the ticket The only graphics that you d see on your monitor were the comics and sticky notes that you stuck to the bottom At the bottom of the screen is a menu of common commands Above the menu is a large empty space where you can enter text much the same as in the word processors that you already know and love For those of us that remember the halcyon character based days of DOS think older versions of Word and WordPerfect or if you re a real computing dinosaur like I am consider the original WordStar Type some text in that area Anything will do aletter to a friend a grocery list or your school homework When you re finished entering your desired text save the document with the WriteOut command in the pico menu Directly next to each command in the pico menu is a keyboard sequenc
21. ommand to find the Process ID PID of the offending process you can halt the process Simply use the ki11 command followed by the PID of the process that you want to stop The man help page for the kill command gives more options that may help terminate stubborn processes with prejudice Do not go killing processes with a cavalier attitude Although Mac OS X is extremely stable removing the wrong process such as init or mach_ init is rather like removing a leg from one of those deep sea drilling platforms the very definition of Not Good You could lock up your system and lose whatever you re doing in other applications If you simply want to shut down a misbehaving program go graphical again at least for a moment and use the Force Quit menu command from the Finder menu Like top another handy command for examining process info is ps short for process Most often you ll want to append a few flags to the ps command to get the information that you desire For example try the following command Book VIII Chapter 1 Weauag syn XINN PUY 654 UNIX Cadillac Commands ps aux The man page for ps explains what each flag means Read more about using the man command in the earlier section Help is on the way UNIX Cadillac Commands Besides working with files and processes the command line has all kinds of sophisticated commands For example with the command line you have instant access to a variety of too
22. or August of this year Another useful command that s related to the cal command is date Type date at the command line to display the day date time and year based on your WHIT computer s settings EDRAGON markchamberss date Mon Jan 15 11 32 20 CDT 2009 Processes Have you ever been curious as to why your hard drive seems to spin and grind on occasion while your system is seemingly inactive Mac OS X sometimes has a lot of stuff going on behind the scenes To discover just what your computer is busy doing at any time use the top command to display all the actions that your computer is currently performing as shown Figure 1 6 The top command displays all running processes NNG Useful Commands 653 in Figure 1 6 These activities are called processes some are created when you launch applications and others are simply tasks that Mac OS X has to take care of to keep things running smoothly Terminal top 81x36 51 total 3 running 1 stuck 47 sleeping 211 threads 01 38 31 0 14 6 16 0 16 CPU usage 2 359 user 7 66 sys 69 95 idle ShorecLibs num 1 resident 55M code 6466K data 8576K Linkedit NenRegions num 4679 resident 156M 125M private 8M shored PhysMem 219M wired 617M active 13M inactive 49M used 1190N free VN 7172M 140M 138551 8 pageins OCO pageouts PID COMMAND ALPU TINE TH PRTS 4NREGS RPRYT RSHRD RSIZE VSIZE 585 top 3 6 1
23. r how many times you d have to click a mouse in the Finder to do the following 1 Find all files that begin with the letters MyDocument 2 From this list of files add a number to the beginning of the filename indicating its size in kilobytes 3 Save the names of all altered files to a text file By using the command line you could accomplish all these tasks by typing only one super command that is a collection of three simple commands combined to form one instruction The built in Terminal program that ships with Mac OS X Snow Leopard gives you everything that you need to start using the command line I show you how in the section Uncovering the Terminal later in this chapter Delving further into super commands isn t for the faint hearted things get pretty ugly pretty quickly and this chapter can only show you the very beginning of the UNIX Yellow Brick Road Therefore if your thirst for UNIX dominance so compels you I invite you to do a little independent study to bone up on the operating system Pick up a copy of the great book of lore entitled UNIX For Dummies 5th Edition written by John R Levine and Margaret Levine Young Wiley Go where no mouse has gone before The Finder is generally a helpful thing but it makes many assumptions about how you work One of these assumptions is that you don t have any need to handle some of the files on your hard drive As I mention in Book II Chapter 6 Mac OS X ships wi
24. r this character is where you enter any command that you wish to execute Go ahead don t be shy Try out your first command by typing uptime in the Terminal application It s a good idea to type UNIX commands in lowercase Your text appears at the location of the cursor denoted by a small square If you make a mistake while entering the command press the Delete key to back up and then type the characters again If the typing error is stuck deep in a longer command press the left or right arrow key to move the cursor immediately after the incorrect character and press Delete to back up then type the correct characters After you type the command press Return to execute it WHITEDRAGON markchambers uptime 6 24PM up 2 42 4 users load averages 2 44 2 38 1 90 WHITEDRAGON markchambers If all goes well you should see a listing of how long your Mac has been run ning since the last reboot or login In the example listing the computer has been running for 2 hours and 42 minutes 2 42 in line 2 Simple eh Immediately following the listing of the uptime command the Terminal displays another prompt for you to enter more commands I examine many more commands later in this chapter Prefer a different appearance for the Terminal window Click the Terminal menu and choose Preferences then click the Settings toolbar button to choose the color combinations for the Terminal window background and text A few commands to get star
25. rl will take care of the rest Of course most people want to save any files that they download via FTP not view them in the Terminal as I did the HTML file Therefore as in the previous example you should add the o flag and a path to the destination of your download This time I download a README file about curl directly from the makers of curl curl o Desktop README curl ftp ftp sunet se pub www utilities curl README curl If you re familiar with FTP you might be wondering whether curl can upload too Yes indeed Instead of using the o flag you need to use two flags T and u The T flag denotes which file you want to upload The u flag denotes the username and password Then specify the FTP destination address of where you want to upload it Because this example deals with an upload the remainder of this example is for an imaginary FTP server In real life you d use the appropriate FTP address username and password for an FTP server where you are allowed to upload curl T Desktop README curl u username passwd ftp ftp yoursitehere com myfiles README curl Book VIII Chapter 1 Weauag sin XINN PUY 658 UNIX Programs That Come in Handy This example uploads the README curl file from the Desktop folder that I downloaded earlier to an imaginary FTP server How do you spell success C u r l Sure HTTP and FTP are handy but did you know that there are many other protocols for
26. sections I describe a few simple command line functions All these commands have something in common You might not have noticed but every example thus far involved folder names and filenames that contained only alphanumeric characters Remember what happens if you have a folder name that has a space in it Try the following example but don t worry when it doesn t work The cd command stands for change directory cd Desktop Folder The result is an error message bash cd Desktop No such file or directory The problem is that a space character isn t allowed in a path To get around this problem simply enclose the path in double quotation marks like this cd Desktop Folder Mac OS X lets you use either double or single quotation marks to enclose a path with spaces in it Standard UNIX operating systems however use double quotation marks for this purpose Book VIII Chapter 1 Weauag syn XINN PUY 646 UNIX Commands 101 Figure 1 3 Use the man command to display help information In a similar vein you can get the space character to be accepted by a command by adding an escape character To escape a character adda backslash immediately prior to the character in question To illustrate try the last command with an escape character instead Note that this time no quotation marks are necessary cd Desktop Folder You can use either quotation marks or escape characters because they re int
27. ted Using the command line is simply a matter of entering simple instructions or commands into the Terminal application and pressing Return to execute them It s easy to use the command line to navigate through the various folders on your hard drive You ll become accustomed to using two vital commands 1s and cd The 1s command is shorthand for list and it does just that It lists the contents of the current directory Enter Is at your prompt and you should see a listing of your Home folder ar ar Uncovering the Terminal 643 The complementary cd command lowercase which incidentally stands for change directory opens any folder that you specify It works much the same as double clicking a folder in the Finder The difference is that following the cd command you don t immediately see all the folder s content However the cd command requires a parameter extra options or information that appear after the command so that your Mac knows which folder to open For example to open the Documents folder that resides in your Home directory type cd Documents and press Return When you do you might be surprised to see another prompt displayed immediately So where are all the files in the Documents folder You must enter another command to see what items are in the folder that you just opened Type Is again to see the contents of the Documents folder If you try to open a folder that has a space in its name make sure to
28. th its system files marked Off Limits and I generally agree with that policy which keeps anyone from screwing up the delicate innards of Mac OS X To secure your system files Apple purposely hides some files from view But what road do you take if you actually need to view or modify those system files Yep you guessed it The command line comes to the rescue You can use the command line to peer inside every nook and cranny of your Mac s vast directory structure on your hard drive It also has the power to edit files that aren t normally accessible to you With the command line you can pretend to be other users even users with more permissions By temporarily acting as another more powerful user you can perform actions with the command line that would be impossible in the Finder Just remember to make sure that you know exactly what you re doing or you re working with an Apple technical support person a wrong move and it ll be time for an Ominous Chord Book VIII Chapter 1 Weauag syn XINN PUY 640 Why Use the Keyboard MBER KV amp Automate to elevate If all these benefits are beginning to excite you hold on to your socks Not only can you perform complex commands with the command line you can go even one step further automation If you find yourself using the same set of commands more than once you re a likely candidate for using automation to save time Instead of typing the list of commands each
29. tility January 26 2009 7 52 PM 27 j All images 3 Remote Install Mac OS X January 17 2009 11 07 PM son All Movies amp System Profiler January 27 2009 3 30 PM 1 2 G All Documents I Terminal 18 2009 2 00 PM 4 6 MN amp VoiceOver Utility January 26 2009 12 13 AM S1BKy 3 lt gt 1 of 23 selected 49 78 GB available By the way feel free to make Terminal more accessible by dragging its icon to the Dock or the toolbar That way you won t have to dive this deep into the Applications folder in the future J What s a prompt Upon launch of the Terminal application you ll immediately notice some text in the window that appears on screen Last login Sun Jun 23 17 51 14 on console WHITEDRAGON markchambers Book VIII Chapter 1 Weauag sin XINN PUY 642 Uncovering the Terminal w As you might guess this text details the last time that you logged into the Terminal The last line however is the more important one It s called the prompt The prompt serves some important functions First it lists the current directory which is listed as A tilde character denotes a user s Home directory By default you re always in your Home folder each time you begin a new session on the Terminal After the current directory the Terminal displays the name of the current user which is markchambers in this example The final character of the prompt is a Consider this your cue because immediately afte
30. u want to type In other words if you don t type enough characters autocompletion ends up like a detective without enough clues to figure things out Working with Files If you ve used a computer for any time at all you re no doubt familiar with the idea of files Even before the first floppy drive appeared in personal computers operating systems have stored data in files they date back to the days when a mainframe computer occupied an entire floor of an office building Mac OS X is no exception and it s important to understand how Mac OS X arranges them into folders and how you go about accessing them via the command line This section describes the basic file and folder information that you need to know to tame the beast that is UNIX Paths Before you dive into UNIX commands you should first know a few facts nasty things facts but you can t earn your pair of techno wizard suspenders without em For starters as a Mac user you might not be familiar with how Book VIII paths work in UNIX A path is simply a textual representation of a folder or Chapter 1 file The simplest path is your Home directory which is denoted by a tilde character the tilde character acts as the equivalent of Users lt your short account name gt in my case Users markchambers Any folder within the Home directory is represented by the folder s name preceded by a gt a forward slash For example a document entitled m
31. use is definitely the way to go but you can perform some other tasks just as quickly if not faster with the keyboard For the skinny on one line commands skip down to the upcoming section Uncovering the Terminal The UNIX keyboard is a powerful beast So maybe you re not an expert typist and using the mouse still sounds inviting For many scenarios you d be correct in assuming that a mouse can handle the job just as quickly and easily as a bunch of commands that you have to memorize Using the keyboard however offers some other distinct advantages over the mouse To allow you to control your computer from the keyboard all UNIX operating systems offer the command line tool With this tool you can enter commands one line at a time hence its name Mac OS X ships with the command line application Terminal You can find it here Applications Utilities Terminal One shining feature of the command line is its efficiency To wit When you use a mouse one mouse click is equal to one command When you use the command line on the other hand you aren t limited to entering one command at a time rather you can combine commands into a kind of super command minus the silly cape but with bulging muscles intact with each command performing some action of the combined whole By using the command line you can string together a whole bunch of commands to do a very complex task ar Why Use the Keyboard 639 For example conside
32. user account The sudo command lets you temporarily become another user presumably one that has permission to perform some function that the current user can t What would file manipulation be without the ability to delete files Never fear UNIX can delete anything that you throw at it Use the rm short for remove or rmdir short for remove directory command to delete a folder or file For example to delete MyNewDocument from the Desktop folder execute the rm command like this rm Desktop MyNewDocument Once again deleting files and folders requires that you have permission to do so In other words any time that you manipulate files with the com mand line you re required to have the proper permission If your current user lacks these permissions using sudo helps You should also check to make sure that your target is correctly spelled and that no pesky spaces that could wreak carnage are lurking in the command Useful Commands 651 Opening documents and launching applications Launching applications and opening documents is child s play for a UNIX pro like you The open command does it all For example to bring the Finder to the foreground without touching the mouse use open System Library CoreServices Finder app To open a document from the command line follow a similar scheme For example to view an image named myImage tif that s stored in your Documents folder using Preview try this open Documents myI
33. xcept for ond Aluays set for the super user 4 Include ctrectory entries whose naves begin with a dot 2 Fores printing of renprinteble characters a2 cetined by ctype 3 ond current locale settings in file noves as xxx where xxx ts the numeric volue of the character in octal AS B but use C escape codes vhanever possible Foret wultt coluyn cutput this 12 the default when output i2 to a terminal lt Lee tive shen file status ce last chenged for sorting or printing KJ Directories are Listed as pleln files not ssorched recurelvely X LI 4 A a utocompletion To speed things along the bash shell can automagically complete your input for you while you type Although the Terminal permits you to enter commands via the keyboard it is the shell that interprets those commands Many kinds of shells are available to UNIX users The shell that Snow Working with Files 64 Leopard uses by default is bash another common shell is tcsh Use the autocompletion features of bash to autocomplete both commands and file names To demonstrate begin by typing the following cd De Then press the Tab key The result is that the shell predicts that you will want to type cd Desktop Of course if you have another folder that begins with the letters De in the same folder you might need to type a few additional characters This gives the autocompletion feature more information to help it decide which characters yo
34. yDoc that resides in D the current user s Documents folder would have a path like this p Documents myDoc 648 Working with Files w ar Similarly a folder named myFolder that resides in the current user s Documents folder would have a path like this Documents myFolder As you ve probably surmised a folder and a directory are two different names for the same thing Folder is the name with which most Mac users are familiar and directory is a term that UNIX power users prefer I use the terms interchangeably throughout the remainder of the chapter Because Mac OS X is a multiuser environment you might sometimes want to work with folders or files somewhere other than in your Home folder Starting from your Home folder enter the following command cd This moves you to the folder right above your Home folder which happens to be the Users folder Using another quick 1s command will show you all users who are permitted to use the machine By the way Shared isn t a user it s a folder with privileges set so that any user can access its contents Enter cd once again and you find yourself at the root of your main hard drive The root directory is what you see in the Finder when you double click your hard drive icon on the Desktop A user s Home directory is represented by a tilde character and the root of the hard drive is denoted by a forward slash as displayed by the prompt WHITEDR
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