Arguments can be passed to an aliased command. Aliases can also be nested. Let's take a look at one of the more complicated aliases, namely, the cd and back aliases. Semicolons are used in these commands to separate individual commands. As you can see, the cd command is actually three commands.
Quotation marks prevent the semicolons from being interpreted as the end of the alias.
IRAF aliases in your login shell will not be redefined and will be unknown to your subshells. Variables One of the shortcomings of aliases is that they can only be used to redefine commands, not arguments. This problem can be seen in the example in Figure 4.7 . But, we forgot that Unix only checks the command name against the alias list, and because it didn't find an alias for cd, it treated our command literally, looking for a directory called myhome. What we really wanted to use was not an alias, but a shell variable.