posix regex example code

regex-eg.c

#include <stdio.h>
#include <stdlib.h>
#include <regex.h>
int main(int argc,char*argv[]){
  char b[1024],i=-1,n=0;
  regex_t re;
  regmatch_t m[9];
  if(argc==1)return 1;
  regcomp(&re,argv[1],REG_EXTENDED|REG_NEWLINE);
  if(argc>2) n=atoi(argv[2]);
  while(fgets(b,1024,stdin)!='\0'){
    if(regexec(&re,b,n,m,0)!=REG_NOMATCH){
      for(i=0;i<n;i++){
        if(i>0)putchar(',');
        while(m[i].rm_so!=m[i].rm_eo)putchar(b[m[i].rm_so++]);
      }
      putchar('\n');
    }
  }
  regfree(&re);
  return (i<0)?1:0;
}