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16.4. Online Help

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16.4. Online Help Mac OS X comes with over 1,200 Unix programs like the ones described in this chapter. How are you supposed to learn what they all do? Fortunately, almost every Unix program comes with a help file. It may not appear within an elegant | 16.4. Online Help Mac OS X comes with over 1 200 Unix programs like the ones described in this chapter. How are you supposed to learn what they all do Fortunately almost every Unix program comes with a help file. It may not appear within an elegant gradient-gray Leopard window in fact it s pretty darned plain but it offers much more material than the regular Mac Help Center. These user-manual pages or manpages hold descriptions of virtually every command and program available. Mac OS X in fact comes with manpages on almost 9 000 topics over 30 000 printed pages worth. Alas manpages rarely have the clarity of writing or the learner-focused approach in the Mac Help Center. They re generally terse just-the-facts descriptions. In fact you ll probably find yourself needing to reread certain sections again and again. The information they contain however is invaluable to new and experienced Unix fans alike and the effort spent mining them is usually worthwhile. 16.4.1. Using man To access the manpage for a given command type man followed by the name of the command you re researching. For example to view the manpage for the ls command enter man ls. Tip The -k option flag lets you search by keyword. For example man -k appletalk produces a list of all manpages that refer to AppleTalk whereupon you can pick one of the names in the list and man that page name. Now the manual appears one screen at a time as shown in Figure 16-7. Figure 16-7. To move on to the next man screen press the Space bar. To go back press the up arrow key or the B key. To close the manual and return to a prompt press Q. You can also search for a certain phrase by typing a to produce the find what prompt thereafter type n to find the next occurrence. A typical manpage begins with these sections Name. The name and a brief definition of the command. Synopsis. Presents the syntax of the command including all possible options and arguments in a concise formula. For example the synopsis for du disk usage is as