Removing an alias

Let's create another temporary alias named lastline that will display the last line in a file:

elliot@ubuntu-linux:~$ alias lastline="tail -n 1"

Now let's try our new alias on the /home/elliot/.bashrc file:

elliot@ubuntu-linux:~$ lastline /home/elliot/.bashrc 
alias date="date;cal"

Alright! It works well. Now, if you wish to delete the alias, then you can run the unalias command followed by the alias name:

elliot@ubuntu-linux:~$ unalias lastline

So now the lastline alias has been deleted:

elliot@ubuntu-linux:~$ lastline /home/elliot/.bashrc 
lastline: command not found

You can also use the unalias command to temporarily deactivate a permanent alias. For example, if you run the following command:

elliot@ubuntu-linux:~$ unalias memory

Now, the permanent alias memory will not work in the current Terminal session:

elliot@ubuntu-linux:~$ memory

Command 'memory' not found, did you mean: 
    command 'lmemory' from deb lmemory
Try...