Using man
I’ve really only scratched the surface of the commands I’ve shown, giving you just enough information to get you started. But they all offer a wide range of options, providing additional control over how they work and the output displayed.
Using the man command, you can
look up everything you could ever want to know about a Bash program. It’s
as easy as entering man followed by the
command name, like this:
man wcThis displays the manual page for the wc command, which you can scroll through a line
at a time by pressing the Enter key, or a page at a time with the space
bar. You can also use the Up and Down cursor keys to scroll back and
forth. To quit the program, press the q
key.
If you have a scroll wheel on your mouse, you can also use that to
scroll back and forth through a man page. Figure 7-9 shows the manpage for the
wc command.

Figure 7-9. The manpage for the wc command
Ubuntu comes packed with masses of such information, so whenever you
are in doubt about how to use a command or what it does, just call up its
manpage. Some manpages tell you that the command is documented in another
page called an info page with more up-to-date or
extended information. You call up an info page by substituting info for man.
Additionally, you can usually get a quick explanation of a command
and its switches using -help in the
following manner, which summarizes the options for the man command ...