fork(1) download 
  1. #include <stdio.h>
  2. #include <regex.h>
  3. #include <string.h>
  4.  
  5. int main() {
  6.  
  7.     regex_t preg;
  8.     char str[] = "dave";
  9.     char regex[] = "\\(.\\)ave";
  10.  
  11.     // flag REG_EXTENDED with unescaped parens in the r.e. doesn't fix anything
  12.     int ret, cflags = REG_ICASE;
  13.  
  14.     // the elements of unused pmatches used to be set to -1 by regexec, but no longer. a clue perhaps.
  15.  
  16.     regmatch_t pmatch[2] = {{-1,-1},{-1,-1}};
  17.  
  18.     ret = regcomp(&preg, regex, cflags);
  19.     if (ret) {
  20.         puts("regcomp fail");
  21.         return ret;
  22.     }
  23.     else
  24.         // preg.re_nsub contains the correct number of groups that regcomp recognized in the r.e. Tests succeeded for 0, 1, 2, and 3 groups.
  25.         printf("regcomp ok; re_nsub=%zu\n", preg.re_nsub);
  26.  
  27.     ret = regexec(&preg, str, 2, pmatch, 0); // 1 changed to 2 as there is Group 0 (whole match) and Group 1 (for the first capturing group)
  28.  
  29.     if(ret)
  30.         puts("no match");
  31.     else {
  32.         printf("match offsets are %d %d\n", pmatch[0].rm_so, pmatch[0].rm_eo);
  33.         printf("match[0]=%*s<\n", pmatch[0].rm_eo, &str[pmatch[0].rm_so]);
  34.  
  35.         printf("submatch offsets are %d %d\n", pmatch[1].rm_so, pmatch[1].rm_eo);
  36.         if(pmatch[1].rm_so != -1) {
  37.             printf("match[1]=%.*s<\n", pmatch[1].rm_eo, &str[pmatch[1].rm_so]);
  38.         }
  39.     }
  40.     return 0;
  41. }
  42. /*
  43. regcomp ok; re_nsub=1
  44. match offsets are 0 4
  45. match[0]=dave<
  46. submatch offsets are 0 1
  47. match[1]=d<
  48. */
Success #stdin #stdout 0.01s 5456KB
comments (?)
stdin 
Standard input is empty
stdout 
regcomp ok; re_nsub=1
match offsets are 0 4
match[0]=dave<
submatch offsets are 0 1
match[1]=d<
https://ideone.com/29j0bs
language:
C (gcc 8.3)
created:
4 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!