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

int main()
{
    int fd[2];
    int f = pipe(fd);
    if (f == -1)
    {
        perror("pipe");
        _exit(1);
    }

    int i = 0;
    for (; i < 2; i++)
    {
        pid_t pid = fork();
        if (pid == 0)
            break;
    }

    if (i == 0)
    {
        close(fd[0]);
        printf("请在子进程 1 中输入一段内容:\n");
        while (1)
        {
            char msg[32] = "";
            fgets(msg, 32, stdin);
            msg[strcspn(msg, "\n")] = '\0'; // 去掉换行符

            write(fd[1], msg, strlen(msg) + 1); // 包括'\0' , 写入管道
            if (strcmp(msg, "bye") == 0)
                break;
        }
        close(fd[1]);
        _exit(0);
    }
    else if (i == 1)
    {
        close(fd[1]);
        while (1)
        {
            char buf[32] = "";
            int len = read(fd[0], buf, 32);
            if (len <= 0)
                break;
            if (strcmp(buf, "bye") == 0)
                break;
            printf("子进程 2 收到子进程 1 数据: %s\n", buf);
        }
        close(fd[0]);
        _exit(0);
    }

    while (1)
    {
        int p_id = waitpid(-1, NULL, 0);
        if (p_id == -1)
            break;
    }

    return 0;
}