test3.c

华清远见应用培训班例程源码

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <string.h>
#include <errno.h>

int main(int argc, char **argv)
{
  pid_t pid;
  int retry;

  //char *p;

  retry = 5;

  while ((pid = fork()) < 0)
  {
    retry--;

    if (retry <= 0)
    {
      fprintf(stderr, "Fatal error: call fork() faild.\n");
      exit(1);
    }
  }

  if (pid == 0)
  {
    //char *arg[] = { "env", NULL };
    char *arg[] = { "test4", "-afx", NULL };
    //char *envp[] = { "PATH=/tmp", "USER=sunq", NULL };

    //if (execv("/bin/pwd", arg) < 0)
    //perror("execve error!");

    //if (execlp("ps1", "ps1", "-afx", NULL)<0)
    //if (execl("/tmp/ps1", "ps1", "-afx", NULL)<0)
    //if (execl("/tmp/ps1", "/tmp/ps1", "-afx", NULL)<0)
    //if (execl("./test4", "test4", "-afx", NULL) < 0)
    if (execv("./test4", arg) < 0)
    {
      fprintf(stderr, "ERROR: call execlp() failed: %s\n", strerror(errno));
    }

    exit(0);
  }

  return 0;
}