(Changing your PATH and adding directories to it are
described later in this chapter.)
Not all the commands that you run are located in directories in your PATH variable. Some commands
are built into the shell. Other commands can be overridden by creating aliases that define
any commands and options that you want the command to run. There are also ways of defining a
function that consists of a stored series of commands. Here is the order in which the shell checks
for the commands you type:
1. Aliases??”Names set by the alias command that represent a particular command and a
set of options. (Type alias to see what aliases are set.) Often, aliases enable you to define a
short name for a long, complicated command.
Getting Help Using the Shell
When you first start using the shell, it can be intimidating. All you see is a prompt. How do you
know which commands are available, which options they use, or how to use advanced features?
Fortunately, lots of help is available. Here are some places you can look to supplement what you
learn in this chapter:
Check the PATH??”Type echo $PATH. You see a list of the directories containing commands
that are immediately accessible to you. Listing the contents of those directories
displays most standard Linux commands.
Pages:
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186