If I have this text in vim, and my cursor is at the first character:


I know that I can do:

  • cw to change up to the first period, because a word (lowercase w) ends at any punctuation OR white space
  • cW to change the whole address, because a Word (uppercase w) ends only at whitespace

Now, what if I have this:


and want to change it to this?


Both cw and cW change the whole thing, but I just want to change the fragment before the underscore.

My fallback technique is c/_, meaning 'change until you hit the next underscore in a search,' but for me, that also causes all underscores to be highlighted as search terms, which is slightly annoying.

Is there a specifier like w or W that doesn't include underscores?


You can do cf_. f won't highlight the searched character.

You can also do ct_ if you don't want to include the _.

  • 15
    You're confusing f, t, F and T. f moves forward to the character; F moves backward to the character; t moves forward to just before the character; and T moves backward to the character to the right of the target character. So your second example should have been ct_. – garyjohn Feb 10 '11 at 16:55
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    This is also incredibly extendable and therefore powerful. I'm guessing you can put any character after the f or t and it will go to the next (or prev for caps) occurrence. Thanks. – Dom Nov 9 '17 at 13:16
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    Vim never fails, only one's understanding of what it is capable of! – Benjamin R Dec 12 '17 at 4:57
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    Mnemonic: change 'til. i.e. ct_ can be remembered as "change 'til underscore". – François Leblanc Apr 4 '18 at 20:30
  • @FrançoisLeblanc That is a great mnemonic, I find those always help me remember vim keys better. :) – Kredns Jun 19 '19 at 12:44

Put this in your .vimrc:

set iskeyword-=_

Then _ will be treated as a word boundary (though not a WORD boundary), and cw could be used to just change "awesome", and cW to change the whole thing.


:help iskeyword


:help word

for more info.

  • 7
    It's great to know that I can define my own word boundaries, but after some thought, I think the best solution is ct_ as doubleface says below, since it's concise and is default vim behavior. – Nathan Long Mar 2 '11 at 12:01
  • This is my personal favorite – Jay Feb 26 '16 at 19:17
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    I like this one, but it breaks my syntax color coding in php. – Aaron Surrain Mar 16 '17 at 18:05
  • How can I unset or toggle this? – Behe Sep 5 '19 at 9:05
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    @Behe you can run :set iskeyword-=_. It will work only in your current vim – Mat M Nov 14 '19 at 14:23

camelcasemotion is a pretty handy vim plugin that allows you to move through words when using underscore or camelcase notation. Using this plugin you can place a comma in front of many of the traditional vim motion commands which will allow you to treat words in underscore or camelcase notation as full words.


As a summary of all previous answers:

There is no specifier to exclude _

You can do cf_. The searched character (_ here) will be included in the replaced string.
You can also do ct_ if you don't want to include the searched character (_ here).

  • f and t won't highlight the searched character in the file, unlike /.
  • f and t allows to search for one character
  • / will allow for a pattern or a longer string , and will not include it, like t
  • If you intend to add more information to an answer, just extend / modify it. Do not copy its content and post it as an own answer. This is plagiarism. – dirdi Nov 14 '19 at 10:03
  • @dirdi I agree. I tried to edit the first answer, but it was rejected and suggested to post on my own. – Mat M Nov 14 '19 at 14:19

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