Vim search in C/C++ code lines

Question

Is there any way to search a string in a C/C++ source file while skipping commented lines?

Answer 1

This is an intriguing question.

I think @sixtyfootersdude has the right idea -- let Vim's syntax highlighting tell you what's a comment and what's not, and then search for matches within the non-comments.

Let's start with a function that mimics Vim's built-in search() routine, but also provides a "skip" parameter to let it ignore some matches:

function! SearchWithSkip(pattern, flags, stopline, timeout, skip) " " Returns true if a match is found for {pattern}, but ignores matches " where {skip} evaluates to false. This allows you to do nifty things " like, say, only matching outside comments, only on odd-numbered lines, " or whatever else you like. " " Mimics the built-in search() function, but adds a {skip} expression " like that available in searchpair() and searchpairpos(). " (See the Vim help on search() for details of the other parameters.) "      " Note the current position, so that if there are no unskipped     " matches, the cursor can be restored to this location.     "     let l:matchpos = getpos('.')      " Loop as long as {pattern} continues to be found.     "     while search(a:pattern, a:flags, a:stopline, a:timeout) > 0          " If {skip} is true, ignore this match and continue searching.         "         if eval(a:skip)             continue         endif          " If we get here, {pattern} was found and {skip} is false,         " so this is a match we don't want to ignore. Update the         " match position and stop searching.         "          let l:matchpos = getpos('.')         break      endwhile      " Jump to the position of the unskipped match, or to the original     " position if there wasn't one.     "     call setpos('.', l:matchpos)  endfunction 

Here are a couple of functions that build on SearchWithSkip() to implement syntax-sensitive searches:

function! SearchOutside(synName, pattern) " " Searches for the specified pattern, but skips matches that " exist within the specified syntax region. "     call SearchWithSkip(a:pattern, '', '', '',         \ 'synIDattr(synID(line("."), col("."), 0), "name") =~? "' . a:synName . '"' )  endfunction   function! SearchInside(synName, pattern) " " Searches for the specified pattern, but skips matches that don't " exist within the specified syntax region. "     call SearchWithSkip(a:pattern, '', '', '',         \ 'synIDattr(synID(line("."), col("."), 0), "name") !~? "' . a:synName . '"' )  endfunction 

Here are commands that make the syntax-sensitive search functions easier to use:

command! -nargs=+ -complete=command SearchOutside call SearchOutside(<f-args>) command! -nargs=+ -complete=command SearchInside  call SearchInside(<f-args>) 

That was a long way to go, but now we can do stuff like this:

:SearchInside String hello 

That searches for hello, but only within text that Vim considers a string.

And (finally!) this searches for double everywhere except comments:

:SearchOutside Comment double 

To repeat a search, use the @: macro to execute the same command repeatedly, like pressing n to repeat a search.

(Thanks for asking this question, by the way. Now that I've built these routines, I expect to use them a lot.)

Answer 2

This pattern searches for a string that is not preceded by the two C++ commenting conventions. I've also excluded '*' as the first non-whitespace character, as that's a common convention for multi-line comments.

/\(\(\/\*\|\/\/\|^\s*\*[^/]\).*\)\@<!foo  

Only the first and fourth foo are matched.

foo /* foo * baz foo */ foo // bar baz foo 

---

Putting \v at the beginning of the pattern eliminates a bunch of backslashes:

/\v((\/\*|\/\/|^\s*\*[^/]).*)@<!foo 

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You can bind a hotkey to this pattern by putting this in your .vimrc

"ctrl+s to search uncommented code noremap <c-s> <c-o>/\v((\/\*\|\/\/\|^\s*\*[^/]).*)@<!