管道linux

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main() {
    int pipefd[2];
    pid_t cpid;
    char buf;

    if (pipe(pipefd) == -1) {
        perror("pipe");
        exit(EXIT_FAILURE);
    }

    cpid = fork();
    if (cpid == -1) {
        perror("fork");
        exit(EXIT_FAILURE);
    }

    if (cpid == 0) {    // 子进程
        close(pipefd[1]); // 关闭写端
        while (read(pipefd[0], &buf, 1) > 0) {
            putchar(buf);
        }
        close(pipefd[0]);
        exit(EXIT_SUCCESS);
    } else {            // 父进程
        close(pipefd[0]); // 关闭读端
        write(pipefd[1], "Hello, World!\n", 14);
        close(pipefd[1]);
        wait(NULL); // 等待子进程结束
        exit(EXIT_SUCCESS);
    }
}