Best Linux Alias Command with Examples
In this article, we are going to discuss on Linux alias command. Alias is nothing but another related simple name of something (Something in the sense it can be anything like it can be a device, human being or maybe something else). Here in Linux the alias means you can give a simple name to a command or we can say a command which is complex/lengthy to type each time for which we can set a simple name so that we don’t need to type the whole command again and again. just type the alias that you set for that command and at back end the alias will execute the command. In simple words, we can use alias to create a shortcut for command and set a simple string or a word for that command to remember that as per our convenience. The benefit of alias is you can set a simple string/word for a frequently used command. But mind it that alias doesn’t replace the command, it’s just a shortcut to that command.
Best Linux Alias Command with Examples
Follow the below Best Linux Alias Command with Examples:
Here I will show you how to create an alias for command and how to use alias command in Linux.
To list current aliases just run the command alias without any option or argument. Refer to the command below.
[[email protected] ~]# alias # To list current aliases alias cp='cp -i' alias l.='ls -d .* --color=auto' alias list='ls -l' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias rm='rm -i' alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
we can create a new alias using alias command, The syntax would look like this :
Syntax: alias [alias_name]=[“Command for which you want to set alias”]
For example, we know that ifconfig command is used to check IP Address information. Here I am going to set an alias for ifconfig as showip. That means when I type showip instead of ifconfig it will show the IP Address information. So lets to that.
[[email protected] ~]# alias showip="ifconfig" # Set alias for "ifconfig" command
Now type the alias i.e. showip to check the IP Address Information.
[[email protected] ~]# showip eth1 Link encap:Ethernet HWaddr 00:0C:29:BE:FE:04 inet addr:192.168.0.104 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:febe:fe04/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:12 errors:0 dropped:0 overruns:0 frame:0 TX packets:19 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2649 (2.5 KiB) TX bytes:1945 (1.8 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:16 errors:0 dropped:0 overruns:0 frame:0 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:960 (960.0 b) TX bytes:960 (960.0 b)
Let’s take another example :
To configure IP address in linux we have to type the below command.
nano /etc/sysconfig/network-scripts/ifcfg-eth0
Instead of a type such a long command, again and again, you can set an alias for the whole command. Here I am giving alias name as confip. Refer to the below command.
[[email protected] ~]# alias confip="nano /etc/sysconfig/network-scripts/ifcfg-eth0" # Set alias for IP Configuration
Now run the alias i.e. confip to confirm if it’s working or not.
[[email protected] ~]# confip
Alias Command Examples
You can also set an alias for command with its arguments, for example, rm -rf, where rm is the command, and -rf is its an argument. To set an alias for such commands you have to enclose the command with its argument in quotes. Refer to the sample output below.
[[email protected] ~]# alias deleteit="rm -rf" [[email protected] ~]# deleteit test.txt # Delete a file using alias
To list all configured aliases just run the alias command without any argument.
[[email protected]calhost ~]# alias # Check current aliases alias confip='nano /etc/sysconfig/network-scripts/ifcfg-eth0' alias cp='cp -i' alias l.='ls -d .* --color=auto' alias list='ls -l' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias rm='rm -i' alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
To remove or delete an alias you can use unalias command. Refer to the command below.
Syntax : unalias [alias name]
[[email protected] ~]# unalias showip # Removing a alias
To remove all listed aliases use the unalias with the argument -a.
[[email protected] ~]# unalias -a # Removing all listed aliases
No doubt alias is a very useful command but still, there is a problem in alias command i.e. if you are logoff/restart the system then all your aliases will lose and you have to set all those aliases again. To avoid this you have to save all your aliases in the .bashrc (It’s a hidden file that is located at the home directory of each user) file to use it permanently.
you can check hidden files by using the ls -a command.
[[email protected] ~]# pwd /root [[email protected] ~]# ls -a . .config .gconf .gvfs Pictures .. .cshrc .gconfd .ICEauthority Public anaconda-ks.cfg data .gnome2 install.log .pulse .bash_history .dbus .gnome2_private install.log.syslog .pulse-cookie .bash_logout Desktop .gnote .local .ssh .bash_profile Documents .gnupg .mozilla .tcshrc .bashrc Downloads .gstreamer-0.10 Music Templates .cache .esd_auth .gtk-bookmarks .nautilus Videos
So let’s go ahead and edit the .bashrc file then enter your required aliases (Highlighted in Blue color below) in that file and save it. Refer to the snapshot below.
[[email protected] ~]# nano .bashrc
Save Alias in the .bashrc file
One more thing we must notice is the alias is working in that user profile only in which we created it. For example, I created the showip alias in root user login. Now let’s try to run that alias in some other user login.
Here I am logging with user itsmarttricks.
[[email protected] ~]# su - itsmarttricks [[email protected] ~]$ showip -bash: showip: command not found
As you can see above system unable to find the alias. the reason behind that is we saved the alias in .bashrc file of root user and each and every user has its own .bashrc file. That means we saved the alias in .bashrc file of root user which is not a concern with user itsmarttricks . If you want to use that alias by logging in itsmarttricks then either add the alias in .bashrc file of user itsmarttricks or add it on the/etc/bashrc file. Once you add the alias in /etc/bashrc file then it will be available for all users that you have in your Linux system and you don’t need to manually add for each and every user.
So to do so follow the below steps. First, edit the /etc/bashrc file.
[[email protected] ~]# nano /etc/bashrc
After editing the file just goes to the end of the file and enter your alias (Highlighted in blue color). Refer to the snapshot below.
Save Alias in bashrc file
Now again login in to user itsmarttricks and try to run the alias, I am sure you will able to get the required output. Refer to the sample output below.
[[email protected] Desktop]# su - itsmarttricks [[email protected] ~]$ showip eth0 Link encap:Ethernet HWaddr 00:0C:29:0F:7F:A8 inet addr:192.168.0.103 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe0f:7fa8/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:698 errors:0 dropped:0 overruns:0 frame:0 TX packets:492 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:888135 (867.3 KiB) TX bytes:38006 (37.1 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:16 errors:0 dropped:0 overruns:0 frame:0 TX packets:16 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:960 (960.0 b) TX bytes:960 (960.0 b)
Let’s Try some more Examples of alias command so that your concept will get more clear.
Example: 1
Create an alias for passwd command. Refer to the command below.
[[email protected] ~]# alias p="passwd"
Now set the password of any user using the alias of passwd command i.e. p
[[email protected] ~]# p itsmarttricks # Set Password using alias Changing password for user itsmarttricks. New password: Retype new password: passwd: all authentication tokens updated successfully.
Example: 2
Create an alias to check swap space.
[[email protected] proc]# alias swaps="cat /proc/swaps" [[email protected] proc]# swaps Filename Type Size Used Priority /dev/sda3 partition 2097144 0 -1
Example : 3
Create an alias to ping to some host, Here I am pinging to localhost.
[[email protected] proc]# alias pingme="ping -c 3 localhost" [[email protected] proc]# pingme PING localhost (127.0.0.1) 56(84) bytes of data. 64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.195 ms 64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.083 ms 64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.099 ms --- localhost ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2000ms rtt min/avg/max/mdev = 0.083/0.125/0.195/0.051 ms
You can check all the above alias using the alias command without any argument.
[[email protected] ~]# alias alias cp='cp -i' alias l.='ls -d .* --color=auto' alias listpart='fdisk -l' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias p='passwd' alias pingme='ping -c 3 localhost' alias rm='rm -i' alias showip='ifconfig' alias startftp='/etc/init.d/vsftpd start' alias swaps='cat /proc/swaps' alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
Also Read – Useful RPM Command With Examples In Linux
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