Hi,

I'm trying to extract a string from another using regex. I'm using the POSIX regex functions (regcomp, regexec ...), and I fail at capturing a group ...

For instance, let the pattern be something as simple as "MAIL FROM:<(.*)>"
(with REG_EXTENDED cflags)

I want to capture everything between '<' and '>'

My problem is that regmatch_t gives me the boundaries of the whole pattern (MAIL FROM:<...>) instead of just what's between the parenthesis ...

What am I missing ?

Thanks in advance,

edit: some code

#define SENDER_REGEX "MAIL FROM:<(.*)>"

int main(int ac, char **av)
{
  regex_t regex;
  int status;
  regmatch_t pmatch[1];

  if (regcomp(&regex, SENDER_REGEX, REG_ICASE|REG_EXTENDED) != 0)
    printf("regcomp error\n");
  status = regexec(&regex, av[1], 1, pmatch, 0);
  regfree(&regex);
  if (!status)
      printf(  "matched from %d (%c) to %d (%c)\n"
             , pmatch[0].rm_so
             , av[1][pmatch[0].rm_so]
             , pmatch[0].rm_eo
             , av[1][pmatch[0].rm_eo]
            );

  return (0);
}

outputs:

$./a.out "012345MAIL FROM:<abcd>$"
matched from 6 (M) to 22 ($)

solution:

as RarrRarrRarr said, the indices are indeed in pmatch[1].rm_so and pmatch[1].rm_eo
hence regmatch_t pmatch[1]; becomes regmatch_t pmatch[2];
and regexec(&regex, av[1], 1, pmatch, 0); becomes regexec(&regex, av[1], 2, pmatch, 0);

Thanks :)