linux 进程间通信 管道

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

int main() {
    int pipefd[2];
    pid_t pid;
    char buffer[256];

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

    pid = fork();
    if (pid == 0) { // 子进程
        close(pipefd[1]); // 关闭写端
        read(pipefd[0], buffer, sizeof(buffer));
        printf("Child received: %s\n", buffer);
        close(pipefd[0]);
    } else { // 父进程
        close(pipefd[0]); // 关闭读端
        write(pipefd[1], "Hello from parent!", 18);
        close(pipefd[1]);
    }

    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

int main() {
    int fd;
    char buffer[256];

    mkfifo("myfifo", 0666); // 创建命名管道

    if ((fd = open("myfifo", O_WRONLY)) == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    write(fd, "Hello from writer!", 18);
    close(fd);

    if ((fd = open("myfifo", O_RDONLY)) == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    read(fd, buffer, sizeof(buffer));
    printf("Reader received: %s\n", buffer);
    close(fd);

    unlink("myfifo"); // 删除命名管道

    return 0;
}

int flags = fcntl(fd, F_GETFL, 0);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);