Recently I was doing lot of text editing on one of my server (for maintenance activity) – where I need to optimize the size of a file by removing all that have specific pattern, sometimes all lines commented lines and sometimes all lines that do not contain a specific pattern.
For example, one of my server had plenty of disabled user accounts (commented lines in /etc/passwd file) – where I need to remove all those disabled accounts (commented ones) using vim. Here’s what I did:
Note: You will have to do this in command mode – ESC and :
If you want to remove all commented lines from a file, then you will have to remove the lines starting with ‘#’.
:g/#/d
(or)
:g/^\#/d
Assume, you want to remove all lines that match/contain specific pattern – then the command is similar to the above one. For example:
:g/somepattern/d
If you want to remove all lines that do not contain a specific pattern, lets says leave all commented lines and delete the rest. Lookout for ‘!’ symbol in the below command
:g!/#/d
The above command will delete all the lines that does not start with ‘#’. Alternatively, you can use the below command.
: v/#/d
In the above command, we use ‘v’ instead of ‘g’ and no ‘!’ is required.
