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Alias command in UNIX


Alias is used for creating alternative names for commands which have got long text as syntax. Also for commands which are very frequently used we can create alias with short letters so , can save some time in typing and getting result.

How to create alias?

alias ALIAS_NAME='COMMAND'

For example :

alias ll='ls -ltra'

So now when we give ll , the result showing will be same as ls -ltra command.

Another example :

alias s='df -h'

This will show the disk free space in the system.

How to view all alias created?

If we simply type 'alias' from the command prompt it will display all the alias created in the system.

Another point to note is , creating an alias will be available in environment level for the particular session only. It is similar to creating a variable. When we close the session the alias is also removed. Usually we keep the alias in .profile file in the home directory, so that every time when we open a UNIX session the alias variables are also assigned and we can use it easily.
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