C语言正则匹配库(regex.h)

#include<stdio.h>
#include<regex.h>
#include<string.h>
int main(int argn, char **argv)
{
  char *pattern = "[0-9]*qq.com";
  char *string = argv[1];
  char buf[100];
  int ret = 0;
  int i = 0;
  // 存放匹配后的信息
  const size_t nmatch = 5;
  regmatch_t pm[5];
  // 存放编译后的信息
  regex_t reg;
  // 编译
  ret = regcomp(&reg, pattern, REG_EXTENDED);
  if (ret != 0)
  {
    printf("编译错误\n");
    return -1;
  }
  // 匹配
  ret = regexec(&reg, string, nmatch, pm, 0);
  if (ret == REG_NOMATCH)
  {
    printf("未匹配到结果\n");
    return 0;
  }
  else if (ret != 0)
  {
    printf("匹配错误\n");
    return -1;
  }
  // 输出匹配结果
  for (i=0;i<nmatch&&pm[i].rm_so!=-1;i++)
  {
    strncpy(buf, string+pm[i].rm_so, pm[i].rm_eo-pm[i].rm_so);
    printf("%d: %s\n", i, buf);
  }
  // 释放
  regfree(&reg);
  return 0;
}