Re: --only-match

[Daiki Ueno]

>>>>> In <address@hidden> 
>>>>>   Paul Eggert <address@hidden> wrote:

> If I understand it correctly, the proposed code prints just the first
> match in each line.  This doesn't sound right to me: it should print
> each match that it finds.  This raises the issue of whether it should
> print overlapping matches; presumably it should.  It also raises the
> issue of how many empty strings occur in a file: presumably it's only
> one per input character, as otherwise 'grep' would loop.

What about moving right one character even if the matching string is
empty?

  while ((match_offset = (*execute) (beg, lim - beg, &match_size, 1))
         != (size_t) -1)
    {
      char const *b = beg + match_offset;
      /* Avoid matching the empty line at the end of the buffer. */
      if (b == lim)
        break;

      /* ... */

      /* If the matching string is empty, skip one character.  */
      if (match_size < 1)
        match_size = 1;
      beg = b + match_size;
    }

It seems to work for me :-)

$ cat test.txt
aaatestaaatestbbb
abatestbaa

$ grep --matching-string --color '[ab]*' test.txt
aaaaaabbb
ababaa

Regards,
-- 
Daiki Ueno