Tip 213 Printable Monobook Previous Next created 2002 · complexity basic · author tarjei · version 5.7

The ex command g is very useful for acting on lines that match a pattern. You can use it with the d command, to delete all lines that contain a particular pattern, or all lines that do not contain a pattern.

For example, to delete all lines containing "profile" (remove the /d to show the lines that the command will delete):

:g/profile/d

More complex patterns can be used, such as deleting all lines that are empty or that contain only whitespace:

:g/^\s*$/d

To delete all lines that do not contain a pattern, use g! , like this command to delete all lines that are not comment lines in a Vim script:

:g!/^\s*"/d

Note that g! is equivalent to v , so you could also do the above with:

:v/^\s*"/d

The next example shows use of \| ("or") to delete all lines except those that contain " error " or " warn " or " fail " (:help pattern):

:v/error\|warn\|fail/d

See also [ edit | edit source ]

Can we delete/not delete the line that precedes the search string?

like, in the below example i want the command to search for "keyword" and then ratain that and the line before that and deletes the test? Thank you!

<< file starts>>

this is the line that preceeds the search string

keyword

asdfgf asdfgf

lkjhj lkjhj

<< file ends>>

Easy, supply a Range to the d command: :g/keyword/-1d . --Fritzophrenic (talk) 22:09, May 20, 2015 (UTC)

Can we remove all even numbered lines in a file using this feature. can we do some kind of math in the pattern. (ex: \=line(".") % 2)

Not really, but you can do that in two steps:

:g/.*/if line('.')%2|call setline(line('.'), '===delete===')|endif :g/^==delete==$/d

If you simply put delete inside the if statement all the lines will be deleted. Much faster solution is to record a macro "ddj" and play it over the file. You could delete lines from several different ranges:

:let range = range(10,15)+range(20,25)+range(30,35) :g/.*/if index(range, line('.')) != -1|call setline(line('.'), '===delete===')|endif :g/^===delete===$/d

But again I think the faster way to do that is to use :[range]d several times.

How would you instead of deleting, replace matched lines with a single newline between remaining lines?

Use s/// instead. Make sure your pattern matches the whole line (by using wildcards and/or anchors), and replace it with nothing:

:s/.*pattern.*//