All executable programs are potential commands in Unix. And then there are the built-in shell commands such as
cd
if
while etc...
By default
bash is the shell used, so for information on
bash try
man bash
and then check out books on
bash in the book store, or search on-line for information about
bash
Typically other user commands come from
ls /bin
ls /usr/bin
Administrator commands tend to come from
ls /sbin
ls /usr/sbin
User install commands tend to be stored in
ls /usr/local/bin
ls /usr/local/sbin
X11 commands are stored in
ls /usr/X11/bin
Many Unix users put scripts and program they have written for personal use in
ls $HOME/bin
MacPorts.org <http://www.macports.org/> puts commands in
ls /opt/local/bin
ls /opt/local/sbin
Fink <http://www.finkproject.org/> puts commands in
ls /sw/bin
ls /sw/sbin
Additional commands and scripts maybe stored in other locations.
Except for personal programs and scripts, most commands will have a *man page* so once you find a command that looks interesting, you can issue the
man filename
and there is a good chance a *man page* will display.
And if all else fails, there is Google.
