CODEWITHSUNDEEP
c++regexstring
neuromancer
neuromancer

Reputation: 55489

How to extract strings from a c++ string using regex

I'm using regex by using #include <regex.h> If I have a string s, how can I use regex to search for a pattern p?

Upvotes: 1

Views: 6024

Answers (2)

Robᵩ
Robᵩ

Reputation: 168626

#include <regex.h>
#include <iostream>
#include <string>

std::string
match(const char *string, char *pattern)
{

// Adapted from:
   http://pubs.opengroup.org/onlinepubs/009695399/functions/regcomp.html

    int    status;
    regex_t    re;
    regmatch_t rm;


    if (regcomp(&re, pattern, REG_EXTENDED) != 0) {
        return "Bad pattern";
    }
    status = regexec(&re, string, 1, &rm, 0);
    regfree(&re);
    if (status != 0) {
        return "No Match";
    }
    return std::string(string+rm.rm_so, string+rm.rm_eo);
}

int main(int ac, char **av) {
    // e.g. usage: ./program abcdefg 'c.*f'
    std::cout << match(av[1], av[2]) << "\n";
}

Upvotes: 4

Suresh
Suresh

Reputation: 183

Check http://msdn.microsoft.com/en-us/library/bb982821.aspx, has detailed usage patter for regex. from MS vc blog.

      const regex r("[1-9]\\d*x[1-9]\\d*");

      for (string s; getline(cin, s); ) {
               cout << (regex_match(s, r) ? "Yes" : "No") << endl;
      }

Upvotes: 1

Related Questions