Regexec problem

[tigrezno]

Hi all, I'm new here.

Just having problems using regexec in C

I want to match a simple pattern several times, like "(string)", but I always get only one result.

Here is my code:

#include <stdio.h>
#include <sys/types.h>
#include <regex.h>

int main() {
        regex_t r;
        char *str = "trying string one string two";
        regmatch_t matches[4];
        int c;

        regcomp(&r, "(string)", REG_EXTENDED | REG_ICASE);
        regexec(&r, str, 4, matches, 0);

        for(c=0; c<4; c++)
                printf("%d\n", matches[c].rm_so);
        regfree(&r);

        return 0;
}

the output is this:

7
7
-1
-1

Tryed the same expression in ruby, and it returned both elements, so I suppose the pattern expression is OK.

What am I doing wrong?
thanks

[tabstop]

You've only got one set of parentheses, so how that can match multiple items I wouldn't know. Regexes only run once per line.

[tigrezno]

You've only got one set of parentheses, so how that can match multiple items I wouldn't know. Regexes only run once per line.

can you elaborate on that?

[tabstop]

We don't have a mechanism like the /g modifier in Perl (at least that I know of, but I don't use C regexes much to speak of) to re-run the pattern on a string. You run the regex on the string, it looks for the longest thing it can find that matches "(string)", finds it at character 7, and that's it. You've matched the entire pattern and you're done. It doesn't take the remainder of the string and run the regex again on the remainder.

[tigrezno]

oh I understand, So, i'll have to move with some pointer over the string and repeating the match.

thanks you so much, problem solved