Networking: A Beginner's Guide
Before you get into a "which interface is better" holy war with someone, remember that both
types of interfaces serve a purpose, with each having weaknesses as well as benefits. In the end,
the person who chooses to master both will come out ahead.
This section covers some of the Linux command-line tools that are most crucial for
day-to-day work. All of the commands discussed in this section are to be performed
in a terminal window. You can open a terminal window by opening the Applications
menu and choosing System Tools, then Terminal. This window displays a prompt
that looks something like [root@hostname /root]#, where hostname is the name of your
Working from the Command Line
One of the difficulties in moving to the Linus command-line interface, especially if you
are used to using Windows command-line tools such as cmd.exe, is dealing with a shell
that has a great number of shortcuts that might surprise you if you're not careful. This
section reviews the most common of these shortcuts.
Under UNIX-based shells such as bash, you expand wildcards seen on the command
line before passing them as a parameter to the application. This is in sharp contrast to
the default mode of operation for DOS-based tools, which often need to perform their
own wildcard expansion. This also means that you must be careful where you use the
The wildcard characters themselves are identical to those in cmd.exe. The asterisk
(*) matches against all filenames, and the question mark (?) matches against single
characters. If you need to use these characters as part of another parameter, you can
"escape" them by placing a backslash (\) in front of them. This character will cause the
shell to interpret a wildcard as just another character.
Environment Variables as Parameters
You can use environment variables as parameters on the command line. This
means that issuing the parameter $FOO will result in passing the value of the FOO
environment variable instead of the string "$FOO."
Under the bash shell, it is possible to execute multiple commands on the same line by
separating them with a semicolon (;). For example, suppose that you want to execute
the following sequence of commands on a single line:
[root@ford /root]# ls -l
[root@ford /root]# cat /etc/hosts