"alias" Command

Learn all about alias command

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The alias command makes it possible to launch any command or group of commands (inclusive of any options, arguments and redirection) by entering a pre-set string (i.e., sequence of characters).

It allows a user to create simple names or abbreviations (even consisting of just a single character) for commands regardless of how complex the original commands are and then use them in the same way that ordinary commands are used.It makes no difference whether double or single quotes are used when creating an alias.

Following command will display help.

root:~# man alias

Example-1

As a trivial example of alias creation, the alias p could be created for the commonly used pwd command.

root:~# alias p='pwd'
root:~# p
/root
root:~#alias vi='vim'

whenever, user type 'alias' without anything then it will display all aliases created. user can search for specific alias as well.

root:~#alias
alias p='pwd'
alias vi='vim'
root:~# alias vi
alias vi='vim'
root:~# alias hello
-bash: alias: hello: not found

Example-2

root:~# alias l='ls -al'
root:~# l
total 1432
drwxr-xr-x  6 root root    4096 Jun  6 10:38 .
drwxr-xr-x 27 root root    4096 Jun  6 09:32 ..
-rw-r--r--  1 root root     734 Apr  5 17:33 .bash_aliases
-rw-------  1 root root   20849 Jun  6 18:12 .bash_history
-rw-r--r--  1 root root     895 Mar 21 09:10 .bashrc
-rw-r--r--  1 root root    9199 May 11 13:05 temp

Example-3

use of aliases is increasing the safety of the system by making commands interactive. This forces the user to confirm that it is desired to perform a specific action and thereby reduces the risk from accidental or impulsive abuse of powerful commands. For example, the rm command, which can remove files and directories and make them virtually unrecoverable, can be made interactive as follows:

root:~# alias rm='rm -i'
root:~# rm temp
rm: remove regular empty file 'temp'?