How to do case insensitive search in Vim

Question

I'd like to search for an upper case word, for example COPYRIGHT in a file. I tried performing a search like:

/copyright/i # Doesn't work

but it doesn't work. I know that in Perl, if I give the i flag into a regex it will turn the regex into a case-insensitive regex. It seems that Vim has its own way to indicate a case-insensitive regex.

lurker · Accepted Answer · 2020-05-15 01:27:45Z

2731

You can use the \c escape sequence anywhere in the pattern. For example:

/\ccopyright or /copyright\c or even /copyri\cght

To do the inverse (case sensitive matching), use \C (capital C) instead.

edited May 15, 2020 at 1:27

lurker

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answered Feb 18, 2010 at 9:18

Chinmay Kanchi

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8 Comments

Alok Singhal Over a year ago

Also, \c can appear anywhere in the pattern, so if you type a pattern and then decide you wanted a case-insensitive search, just add a \c at the end.

Nicky McCurdy Over a year ago

I like to add set ignorecase for case-insensitive searching in my vimrc, and I can use \C to do a case-sensitive search similar to what @AlokSinghal mentioned.

Zaz Over a year ago

There's also set smartcase which will automatically switch to a case-sensitive search if you use any capital letters.

Tan Wang Over a year ago

Just want to add to Zaz's comment. set smartcase applies only when set ignorecase is already active. I was stumped on this for a while. See Vim Tips.

Aaron McDaid Over a year ago

@coderMe, It's the capitalization, \c versus \C

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DrAl · Accepted Answer · 2016-11-29 09:24:42Z

875

As well as the suggestions for \c and ignorecase, I find the smartcase very useful. If you search for something containing uppercase characters, it will do a case sensitive search; if you search for something purely lowercase, it will do a case insensitive search. You can use \c and \C to override this:

:set ignorecase :set smartcase /copyright " Case insensitive /Copyright " Case sensitive /copyright\C " Case sensitive /Copyright\c " Case insensitive

See:

:help /\c :help /\C :help 'smartcase'

edited Nov 29, 2016 at 9:24

answered Feb 18, 2010 at 12:11

DrAl

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6 Comments

huyz Over a year ago

The problem with ignorecase is that it affects substitutions as well as searches. I find that it makes sense to have (smart) case-insensitive searches but case-sensitive substitutions by default. But there's no way to do that that I know.

Skilldrick Over a year ago

Worth noting that for smartcase to work, you also need set ignorecase. Great tip though, thanks!

Anthony DiSanti Over a year ago

I believe you could just use a \C in your search expression for substitutions, like this: :%s/lowercasesearch\C/replaceString/g. This doesn't create the default functionality you desire, but it does allow you to force case-sensitivity for replacements while still benefiting from smartcase when searching.

Rory O'Kane Over a year ago

You can also set the I flag on a substitution to force the pattern to be case-sensitive. Like :%s/lowercasesearch/replaceString/gI.

mcella Over a year ago

Note from the help page (useful if you are "*" addicted like me):

After	"*" and "#" you can make 'smartcase' used by doing a "/" command,	recalling the search pattern from history and hitting <Enter>.

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Nathan Fellman · Accepted Answer · 2010-02-18 09:18:44Z

376

You can set the ic option in Vim before the search:

:set ic

To go back to case-sensitive searches use:

:set noic

ic is shorthand for ignorecase

answered Feb 18, 2010 at 9:18

Nathan Fellman

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1 Comment

bluppfisk Over a year ago

also your only option if you're unlucky enough to still use Vi instead of Vim. \c doesn't work in vi.

Paolo Tedesco · Accepted Answer · 2010-02-18 09:19:42Z

72

You can issue the command

:set ignorecase

and after that your searches will be case-insensitive.

answered Feb 18, 2010 at 9:19

Paolo Tedesco

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Comments

Matthieu · Accepted Answer · 2018-08-19 15:42:49Z

You can use in your vimrc those commands:

set ignorecase - All your searches will be case insensitive
set smartcase - Your search will be case sensitive if it contains an uppercase letter

You need to set ignorecase if you want to use what smartcase provides.

I wrote recently an article about Vim search commands (both built in command and the best plugins to search efficiently).

It seems that set smartcase does not perform case insensitive searches if I do not use uppercase letters...is that normal?
Ok, just read below that you have to both set ignorecase and smartcase to have it work. Sorry about that!

vbd · Accepted Answer · 2010-02-23 11:51:08Z

52

To switch between case sensitive and insensitive search I use this mapping in my .vimrc

nmap <F9> :set ignorecase! ignorecase?

answered Feb 23, 2010 at 11:51

vbd

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5 Comments

Boris Brodski Over a year ago

Yes, but ignorecase? shows you the current state of the flag. (in the command line)

Ben Hillier Over a year ago

Thank you! To me, this is the most useful answer on the page: a way to quickly toggle between the two modes depending on what you're searching for at that exact moment.

COil Over a year ago

Yes, it's better to have ignorecase? so you know the current state.

COil Over a year ago

BTW, it's better to add <Cr> at the end, so the command is validated, and you don't have to hit the enter key (at least with neovim).

Anton Samokat Jan 15 at 12:33

non-recursive mapping can be used instead of recursive: nnoremap <F9> :set ignorecase! ignorecase?<CR>

Yogesh Jilhawar · Accepted Answer · 2020-12-01 17:02:30Z

By default, all searches in vi are case-sensitive. To do a case-insensitive search, go into command mode (press Escape), and type-
:set ignorecase
You can also type - :set ic as an abbreviation.

To change back to case-sensitive mode, type-
:set noignorecase or :set noic in command mode

Mick · Accepted Answer · 2017-11-18 01:18:29Z

29

The good old `vim[grep]` command..

:vimgrep /example\c/ &

\c for case insensitive
\C for case sensitive
% is to search in the current buffer

answered Nov 18, 2017 at 1:18

Mick

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3 Comments

Vitaly Zdanevich Over a year ago

Cannot open file "&"

oarfish Over a year ago

I guess he they meant % instead of %.

Santh Over a year ago

Typo in the actual command the correct one is as per the gif attached. vimgrep /example\c %

Thomas · Accepted Answer · 2018-08-13 11:10:06Z

29

As others suggested:

:set ic

But the cool stuff is You can toggle such modes with:

:set ic!

edited Aug 13, 2018 at 11:10

answered Jan 19, 2017 at 9:34

Thomas

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Comments

Nick Tsai · Accepted Answer · 2017-06-15 01:54:57Z

23

I prefer to use \c at the end of the search string:

/copyright\c

answered Jun 15, 2017 at 1:54

Nick Tsai

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Comments

Community · Accepted Answer · 2015-11-24 15:02:29Z

19

put this command in your vimrc file

set ic

always do case insensitive search

edited Nov 24, 2015 at 15:02

CommunityBot

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answered May 19, 2015 at 10:31

WALID BELRHALMIA

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1 Comment

user1510539 Over a year ago

I don't know why but my vim is set to case-insensitive by default, to counter this. use set noic.

pbogut · Accepted Answer · 2016-02-12 09:58:00Z

As @huyz mention sometimes desired behavior is using case-insensitive searches but case-sensitive substitutions. My solution for that:

nnoremap / /\c nnoremap ? ?\c

With that always when you hit / or ? it will add \c for case-insensitive search.

Not a bad suggestion, but does it prevent you from using the smartcase option?

Gowthaman D · Accepted Answer · 2017-03-13 05:38:09Z

5

Vim have 2 modes

1.edit mode

normal mode( Esc )

Search will work for normal mode

/\c for case sensitive

/\csearch

answered Mar 13, 2017 at 5:38

Gowthaman D

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1 Comment

user202729 Over a year ago

What about visual mode?

Steely Wing · Accepted Answer · 2017-07-04 01:40:19Z

4

You can set ignorecase by default, run this in shell

echo "set ic" >> ~/.vimrc

answered Jul 4, 2017 at 1:40

Steely Wing

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Comments

Manuel Lazo · Accepted Answer · 2020-08-02 15:15:34Z

Some important information, if u want to find out more about the commands of vim, as mentioned below u can give a try the following steps :

invoke the command "help" follow by a space and then complete the word with TAB key, once u find the right command press return key.

:help ignorecase

information like the following will be displayed :

you will be able to move forward and backward and also watch the short command, such as the case of "ignorecase" ( 'ic' ). In addition, another short example could be the case of 'smartcase' ('scs' and some more) :

In order to leave of the documentation just type ":q" as usual and you will return to "command mode" .

:q

I really hope the information provided would be helpful for someone.

Best regards,

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