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==Simple commands to remove unwanted whitespace== |
==Simple commands to remove unwanted whitespace== |
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− | In a search, < |
+ | In a search, <code>\s</code> finds whitespace (a space or a tab), and <code>\+</code> finds one or more occurrences. |
Delete all trailing whitespace (at the end of each line) with: |
Delete all trailing whitespace (at the end of each line) with: |
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− | With the following mapping a user can press F5 to delete all trailing whitespace. The variable < |
+ | With the following mapping a user can press F5 to delete all trailing whitespace. The variable <code>_s</code> is used to save and restore the last search pattern register (so next time the user presses <code>n</code> they will continue their last search), and <code>:nohl</code> is used to switch off search highlighting (so trailing spaces will not be highlighted while the user types). The <code>e</code> flag is used in the substitute command so no error is shown if trailing whitespace is not found. Unlike before, the substitution text must be specified in order to use the required flag. |
<pre> |
<pre> |
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:nnoremap <silent> <F5> :let _s=@/<Bar>:%s/\s\+$//e<Bar>:let @/=_s<Bar>:nohl<CR> |
:nnoremap <silent> <F5> :let _s=@/<Bar>:%s/\s\+$//e<Bar>:let @/=_s<Bar>:nohl<CR> |
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==Automatically removing all trailing whitespace== |
==Automatically removing all trailing whitespace== |
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− | One way to make sure to remove all trailing whitespace in a file is to set an < |
+ | One way to make sure to remove all trailing whitespace in a file is to set an <code>autocmd</code> in your .vimrc file. Everytime the user issue a <code>:w</code> command, Vim will automatically remove all trailing whitespace before saving. |
<pre> |
<pre> |
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autocmd BufWritePre * :%s/\s\+$//e |
autocmd BufWritePre * :%s/\s\+$//e |
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</pre> |
</pre> |
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− | However, this is a very dangerous autocmd to have as it will always strip trailing whitespace from every file a user saves. Sometimes, trailing whitespace is desired, or even essential in a file so be careful when implementing this < |
+ | However, this is a very dangerous autocmd to have as it will always strip trailing whitespace from every file a user saves. Sometimes, trailing whitespace is desired, or even essential in a file so be careful when implementing this <code>autocmd</code>. |
One method to mitigate this issue in a .vimrc file, where trailing whitespace matters, is to change how .vimrc prepends wrapped lines. For example, add the following into the .vimrc: |
One method to mitigate this issue in a .vimrc file, where trailing whitespace matters, is to change how .vimrc prepends wrapped lines. For example, add the following into the .vimrc: |
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</pre> |
</pre> |
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− | Now when saving the .vimrc it will use < |
+ | Now when saving the .vimrc it will use <code>"> \"</code> instead of <code>"> "</code> to prepend wrapped lines. |
− | A user can also specify a particular filetype in an < |
+ | A user can also specify a particular filetype in an <code>autocmd</code> so that only that filetype will be changed when saving. The following only changes files with the extension .pl: |
<pre> |
<pre> |
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autocmd BufWritePre *.pl :%s/\s\+$//e |
autocmd BufWritePre *.pl :%s/\s\+$//e |
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</pre> |
</pre> |
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− | Additionally, a FileType autocommand can be used to restrict the < |
+ | Additionally, a FileType autocommand can be used to restrict the <code>autocmd</code> to certain file types only. |
<pre> |
<pre> |
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autocmd FileType c,cpp,java,php autocmd BufWritePre <buffer> :%s/\s\+$//e |
autocmd FileType c,cpp,java,php autocmd BufWritePre <buffer> :%s/\s\+$//e |
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</pre> |
</pre> |
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− | ==See |
+ | ==See also== |
− | *{{help|:autocmd}} - Additional information on < |
+ | *{{help|:autocmd}} - Additional information on <code>autocmd</code> |
==Related scripts== |
==Related scripts== |
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− | Marks are unnecessary, at least in Vim 7. |
+ | Marks are unnecessary, at least in Vim 7. (Yes, that *.{cpp,h,c,etc} syntax is valid. Much better than *.cpp,*.h,*.c,*.etc IMHO.) |
<pre> |
<pre> |
Revision as of 05:53, 13 July 2012
created 2005 · complexity intermediate · author Bertram Scharpf · version 6.0
Simple commands to remove unwanted whitespace
In a search, \s
finds whitespace (a space or a tab), and \+
finds one or more occurrences.
Delete all trailing whitespace (at the end of each line) with:
:%s/\s\+$//
Like with ed(1), the substitution text can be omitted if blank:
:%s/\s\+$
More rarely, a user might want to delete (leading) whitespace at the beginning of each line:
:%s/^\s\+ " Same thing (:le = :left = left-align given range): :%le
With the following mapping a user can press F5 to delete all trailing whitespace. The variable _s
is used to save and restore the last search pattern register (so next time the user presses n
they will continue their last search), and :nohl
is used to switch off search highlighting (so trailing spaces will not be highlighted while the user types). The e
flag is used in the substitute command so no error is shown if trailing whitespace is not found. Unlike before, the substitution text must be specified in order to use the required flag.
:nnoremap <silent> <F5> :let _s=@/<Bar>:%s/\s\+$//e<Bar>:let @/=_s<Bar>:nohl<CR>
See Highlighting whitespaces at end of line to display, rather than delete, unwanted whitespace.
Display or remove unwanted whitespace with a script
The following is a more elaborate procedure that can display or remove unwanted whitespace. Here, "unwanted" means any spaces before a tab character, or any space or tab at the end of a line.
function ShowSpaces(...) let @/='\v(\s+$)|( +\ze\t)' let oldhlsearch=&hlsearch if !a:0 let &hlsearch=!&hlsearch else let &hlsearch=a:1 end return oldhlsearch endfunction function TrimSpaces() range let oldhlsearch=ShowSpaces(1) execute a:firstline.",".a:lastline."substitute ///gec" let &hlsearch=oldhlsearch endfunction command -bar -nargs=? ShowSpaces call ShowSpaces(<args>) command -bar -nargs=0 -range=% TrimSpaces <line1>,<line2>call TrimSpaces() nnoremap <F12> :ShowSpaces 1<CR> nnoremap <S-F12> m`:TrimSpaces<CR>`` vnoremap <S-F12> :TrimSpaces<CR>
This is a similar function which similates the manual steps for removing the whitespace.
function StripTrailingWhitespace() if !&binary && &filetype != 'diff' normal mz normal Hmy %s/\s\+$//e normal 'yz<CR> normal `z endif endfunction
However, this has minor side-effects, such as influencing undo history and sometimes changing scroll position.
Automatically removing all trailing whitespace
One way to make sure to remove all trailing whitespace in a file is to set an autocmd
in your .vimrc file. Everytime the user issue a :w
command, Vim will automatically remove all trailing whitespace before saving.
autocmd BufWritePre * :%s/\s\+$//e
However, this is a very dangerous autocmd to have as it will always strip trailing whitespace from every file a user saves. Sometimes, trailing whitespace is desired, or even essential in a file so be careful when implementing this autocmd
.
One method to mitigate this issue in a .vimrc file, where trailing whitespace matters, is to change how .vimrc prepends wrapped lines. For example, add the following into the .vimrc:
set wrap set linebreak " note trailing space at end of next line set showbreak=>\ \ \
Now when saving the .vimrc it will use "> \"
instead of "> "
to prepend wrapped lines.
A user can also specify a particular filetype in an autocmd
so that only that filetype will be changed when saving. The following only changes files with the extension .pl:
autocmd BufWritePre *.pl :%s/\s\+$//e
Additionally, a FileType autocommand can be used to restrict the autocmd
to certain file types only.
autocmd FileType c,cpp,java,php autocmd BufWritePre <buffer> :%s/\s\+$//e
See also
- :help :autocmd - Additional information on
autocmd
Related scripts
- The DeleteTrailingWhitespace plugin offers a eponymous command, and can remove trailing whitespace automatically when the buffer is written.
- The trailing-whitespace plugin defines :FixWhitespace.
- The bad-whitespace plugin defines :EraseBadWhitespace.
- The Trailer Trash plugin defines :Trim.
Comments
Here's what I use in my .vimrc:
" Removes trailing spaces function TrimWhiteSpace() %s/\s*$// '' :endfunction set list listchars=trail:.,extends:> autocmd FileWritePre * :call TrimWhiteSpace() autocmd FileAppendPre * :call TrimWhiteSpace() autocmd FilterWritePre * :call TrimWhiteSpace() autocmd BufWritePre * :call TrimWhiteSpace() map <F2> :call TrimWhiteSpace()<CR> map! <F2> :call TrimWhiteSpace()<CR>
My preferred setting of list and listchars so that I can see my whitespace instead of removing it:
set list listchars=tab:»·,trail:·
This gives:
»·······text after tab with four spaces after it····
Or try
set list lcs=tab:·⁖,trail:¶
This gives:
·⁖⁖⁖⁖⁖⁖⁖text after tab with four spaces after it¶¶¶¶
There is one occasion where I want to keep my trailing space. But even in those documents, I want to keep it in only in one place, and not every occurrence.
Here is my substitution pattern:
s/\(^--\)\@<!\s*$//
This will eliminate all trailing whitespaces except for the one in an email signature marker (-- ). See wikipedia:Signature block.
In the function in the tip, this expands to:
execute a:firstline.",".a:lastline."substitute /\\(^--\\)\\@<!\\s*$//ge"
Also, I've found the autocmds to work better like this:
autocmd FileWritePre * :TrimSpaces autocmd FileAppendPre * :TrimSpaces autocmd FilterWritePre * :TrimSpaces autocmd BufWritePre * :TrimSpaces
(taking advantage of the default range defined in Betram's command definition)
I modified one of the above scripts to let the user know if whitespace was found
" automatically remove trailing whitespace before write function! StripTrailingWhitespace() normal mZ %s/\s\+$//e if line("'Z") != line(".") echo "Stripped whitespace\n" endif normal `Z endfunction autocmd BufWritePre *.cpp,*.hpp,*.i :call StripTrailingWhitespace()
I didn't get the *
match to work so I used *.*
instead:
autocmd BufWritePre *.* :%s/\s\+$//e
Marks are unnecessary, at least in Vim 7. (Yes, that *.{cpp,h,c,etc} syntax is valid. Much better than *.cpp,*.h,*.c,*.etc IMHO.)
autocmd BufWritePre *.{cpp,h,c,etc} call StripTrailingWhite() function! StripTrailingWhite() let l:winview = winsaveview() silent! %s/\s\+$// call winrestview(l:winview) endfunction