操作系统：利用fork（）进行虚拟机环境下的多进程编程

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>   
int main(int argc, char *argv[]){
  pid_t pid;
        pid = fork();
  while(1){
        if (pid == -1) {
              perror("fork error");
              exit(1);
          } 
  else if (pid == 0) {
              printf("child process processID %d pid value %d\n",getpid(),pid);
    sleep(1);
          } 
  else {
              printf("father process processID %d pid value %d\n",getpid(),pid);
    sleep(1);
          }
  }
        return 0;
    }