APUE_examples

APUE.ch.8.process

// APUE.Chapter.8
// fork(), exec(), wait()
// Michael.Fan

#include <unistd.h>
#include <stdio.h>
#include <sys/wait.h>

int main ()
{
    pid_t fpid; //fpid表示fork函数返回的值
    int count=0;
    int status;
    fpid = vfork();
    if (fpid < 0)
        printf("error in fork!");
    else if (fpid == 0) {
        char * argv[] = {" ."};
        execv("/bin/ls", argv);
        printf("i am the child process, my process id is %d\n",getpid());
        printf("我是儿子\n\n");//对某些人来说中文看着更直白。
        count++;
        _exit(0);
    }
    if (wait(&status) == fpid) {
        printf("i am the parent process, my process id is %d\n",getpid());
        printf("我是爹\n");
        printf("我儿子进程id是：%d\n", fpid);
        count++;
    }
    printf("统计结果是: %d\n",count);
    return 0;
}