Command AliasesIf you always run a command with the same set of options, you can have bash create an alias for it. This alias will incorporate the required options, so that you don't need to remember them or manually type them every time. For example, if you always run ls with the -l option to obtain a detailed directory listing, you can use this command:
root@server # alias ls='ls -l'
To create an alias that automatically includes the -l option. Once this alias has been created, typing ls at the bash prompt will invoke the alias and produce the ls -l output.
You can obtain a list of available aliases by invoking alias without any arguments, and you can delete an alias with unalias.
Quickly jump to frequently-used directoriesYou probably already know that the $PATH variable lists bash's "search path" - the directories it will search when it can't find the requested file in the current directory. However, bash also supports the $CDPATH variable, which lists the directories the cd command will look in when attempting to change directories. To use this feature, assign a directory list to the $CDPATH variable, as shown in the example below:
root@server # CDPATH='.:~:/usr/local/apache/
root@server # export CDPATH
Now, whenever you use the cd command, bash will check all the directories in the $CDPATH list for matches to the directory name.