sympleko (Matthew Leingang) writes "In Neal Stephenson's manifesto In the Beginning was the Command Line , he writes about his favorite command-line utility: wc. As simple as can be, wc counts characters, words, and lines in a file. There's no GUI analogue, perhaps because anybody tempted to make one would add too many "features" that cluttered its ease of use. Think: do you know how to count the words in a Word file? BBEdit is a little easier, if you know the button to click." Read on for Leingang's review of Learning Unix for Mac OS X Panther, which seeks to reconcile the conception of user friendliness in OS X's Aqua with the sometimes-denigrated command line.
You can do a tremendous amount of stuff in Mac OS X Panther without ever touching the command line. This includes editing files, transferring them to remote locations, running a web server, and writing programs. Legend has it that some Apple developers wanted to ship OS X without a command-line application because it's anathema to the Mac "experience." But as Unix geeks will tell you, there are tasks which are much better suited to the command line. Routine, repeated, and automated tasks are some, as well as quick-and-easy access to files and directories.
This book is for the skilled Mac user who would like to know a little more about the operating system behind the scenes. There's also information about the Mac's brand of Unix, so someone familiar with Unix but new to the Mac will also find stuff to learn. For those confident in their Mac and Unix skills, however, there's not much new in the book's 168 pages. That's not to say it's a bad book; I found it quite enjoyable to read, and it's a good title to keep in mind to recommend to a Unix novice.
The book begins with an introduction to Terminal.app, the Mac's Unix terminal program. From the very basic (how to find with the Finder) to the fun (how to change the text and background colors) to the useful (how to save terminal sessions into double-clickable .term files), there's much that Terminal has to offer. There's even the cryptic echo '^2;My-Window-Title^G' command to change the title of Terminal's window.
The authors then introduce a few simple commands like date and who, and show how to manipulate the terminal's prompt. There's also alias which creates command shortcuts. For instance, if you always run ls with the -F flag, a command alias ls "ls -F" will save you some typing.
Each chapter has two sections which stand out. The "Practice" section gives a list of exercises to try, and the "Problem Checklist" is there to diagnose and fix unexpected behavior.
It's important (especially for those used to other OSes) to understand that in Unix, everything is a file, and all files are organized in the filesystem. This includes plain files, which might be Word documents or system logs; directories, which break up the filesystem into a tree; links, which allow file reuse with different names; devices, drives, etc. All these building blocks of the operating system are discussed. There are also a few pages on vi (which I found quite useful as my vi knowledge up to that point consisted of :q!.) and pico.
Printing on Mac OS X is much like printing on any Unix operating system; you can use pr to format text for line printing, enscript to format for PostScript printing, and lpr to actually queue a printer job. The addition that the Mac provides is a CLI to AppleTalk printers. You can use at_cho_prn to choose an AppleTalk printer and atprint to print to one.
One of Unix's biggest features is its ability to put together small programs to do many different tasks. To count how many files under your home directory are named foo, you can do find ~ -type f -name "foo" | wc -l. By breaking down a problem into components, you only need one-counting program, one file-finding program, etc. The book has a good chapter on this input/output redirection, and how to use those magic top-row characters |, >, >>, and <. Grep (and some light regular expressions) and sort are mentioned as tools for examining text. I thought sed would make a nice addition to this chapter, but perhaps it would lengthen the book too much.
Another advantage of Unix is its true multitasking. What may surprise newcomers to the command-line is that it is possible to run many jobs at once with a single interface. By running commands in the background, one can start large jobs and do other tasks while waiting. In the chapter on multitasking, the & modifier is covered, along with fg, bg, and kill to manipulate processes, and ps and top to report on them.
The command-line interface is lightweight enough that it can easily be extended by a network. This means it's easy (in fact, commonplace) to control a computer different from the one in front of which you're sitting. The authors cover the remote-shell commands ssh and its non-secure cousins, as well as other tools for accessing the internet such as ftp and curl.
The book closes with an introduction to the wealth of open-source software available for Macintosh, now that Macs run a functional Unix. The graphical Unix applications require an X server, which is easy to download and install. The authors show how to install Fink, the Macintosh open-source package manager, and a few big applications like OpenOffice.org and The Gimp.
The last chapter is both a resource list and suggestions for further directions. Those who learn a lot from this book may be interested in picking up shell programming or a scripting language such as Perl.
As I said at the beginning, the book is basic and well-written. Even if you feel it's beneath you, keep the title in mind when a newbie asks what the command-line is all about.
Matthew Leingang is a Preceptor in Mathematics at Harvard University. A funny sentence in the third person escapes him at the moment. You can purchase Learning Unix for Mac OS X Panther from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.