An example of using regex in C

regex_example.c

#include <stdlib.h> 
#include <string.h>
#include <regex.h>
#include <stdio.h>

int main() {
  regex_t *preg = calloc(1, sizeof(regex_t));
  int numoffsets = 5;
  regmatch_t pmatch[numoffsets];
  
  int rc = regcomp(preg, "^.*(foo).(bar).*$", REG_EXTENDED);
  printf("regcomp output = %i\n", rc);
  
  int res = regexec(preg, "one foo-bar two", numoffsets, pmatch, 0);
  printf("regexec output = %i\n", res);
  
  int i;
  for(i = 0; i < numoffsets; ++i) {
    printf("found (%lld, %lld)\n", pmatch[i].rm_so, pmatch[i].rm_eo);
  }
  
  regfree(preg);
  return 0;
}