#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <ctype.h>        /* 允许建立的子进程个数最大值 */
#define MAX_CHILD_NUMBER 10    /* 子进程睡眠时间 */
#define SLEEP_INTERVAL 2
int proc_number = 0;        /* 子进程的自编号，从0开始 */
void do_something ();

int
main (int argc, char *argv[])
{

  /* 子进程个数 */
  int child_proc_number = MAX_CHILD_NUMBER;

  int i, ch;

  pid_t child_pid;

  pid_t pid[MAX_CHILD_NUMBER] = { 0 };    /* 存放每个子进程的id */

  if (argc > 1)            /* 命令行参数第一个参数表示子进程个数 */
    {
      child_proc_number = atoi (argv[1]);
      child_proc_number = (child_proc_number > 10) ? 10 : child_proc_number;
    }
  //……
  child_pid = fork ();
  for (i = 0; i < child_proc_number; i++)
    {
      if (child_pid < 0)
    {
      perror ("creat child ps error!");
      exit (1);
    }
      else if (child_pid == 0)
    {
      do_something ();
    }
      else
    {            //Only parent Process  creat child process
      pid[i] = child_pid;
      printf
        ("===================>creat child ps:%d, pid[%d] finished!\n",
         child_pid, i);
      child_pid = fork ();
    }
    }

  while ((ch = getchar ()) != 'q')
    {

      if (isdigit (ch))
    {
      /* pid[ch-'0']发信号SIGTERM，
       * 杀死该子进程 */
      int ret;
      ret = kill (pid[ch - '0'], SIGKILL);
      if (!ret)
        {
          printf ("Kill child ps pid[%d]\n", ch - '0');
        }
    }

    }

  /* 在这里填写代码，杀死本组的所有进程 */
  if (!kill (0, SIGKILL))
    {
      printf ("Kill all child ps!\n");
    }
  return 1;

}

void
do_something ()
{

  for (;;)
    {

      printf ("This is process No.%d and its pid is %d\n", proc_number,
          getpid ());
      sleep (SLEEP_INTERVAL);    /* 主动阻塞两秒钟 */
    }

}