Some hints on getting more information and explanations about unix commands

Google Search for "frequently used unix commands"

LLNL's Quick Reference of Frequently used Unix Commands

Very basic unix commands...

As a side note, the apropos command is useful for finding which section of the manual the page you are looking for resides. ("apropos less" finds all the manpages which mention the word less in their description.)

E.g. looking for less, we see there are two commands called less, which I've highlighted, one in section (1) and another in section (3).


% apropos less UNIVERSAL UNIVERSAL (3) - base class for ALL classes (blessed references) jpegtran jpegtran (1) - lossless transformation of JPEG files less less (3) - perl pragma to request less of something from the compiler min min (9f) - return the lesser of two integers less less (1) - opposite of more lesskey lesskey (1) - specify key bindings for less

Since the manpage for less from section 3 didn't give us what we wanted to see, this suggests we look at the less manpage in the other section ("man -s1 less", even though the description "opposite of more" doesn't really explain anything.

It's also important to know that your shell has built in commands which will probably not have manual pages of their own. For example "man set" on the OCF will find the command "set" for the TCL scripting language, which is probably not what you want. If you type "which set" you will be told that set is a built-in shell command. To read about the set command, you will need to look at the manpage for your shell (e.g. "man csh").

This brings us to the problem of knowing what shell you are using. The most common default shells are sh, csh, bash, and less likely, tcsh, zsh or ksh. You can check your processes and find out which shell you are using, e.g. "ps" will give you something like:

% ps PID TTY TIME CMD 10380 pts/4 0:00 tcsh 10362 pts/4 0:00 csh

Man pages can be difficult to read, an require some getting used to. You can find information about many commands online. Try a google search for "unix command foo" if the manpage is unhelpful to you.

There are some useful unix books out there. In particular the "Unix Power Tools" mentioned above and the O'Reilly & Associates "Unix in a Nutshell" is said to have a reasonable level of information about commands, while not being as confusing as a manpage.