4.3.11 Command alias

You can set an alias for the frequently used command. For example:

     $ alias la='ls -la'

Now, la works as a short hand for ls -la which lists all files in the long listing format.

You can identity exact path or identity of the command using type command. For example:

     $ type ls
     ls is hashed (/bin/ls)
     $ type la
     la is aliased to `ls -la'
     $ type echo
     echo is a shell builtin
     $ type file
     file is /usr/bin/file

Here ls was recently searched while file was not, thus ls is "hashed", i.e., the shell has an internal record for the quick access to the location of the ls command.