命名管道(FIFO)是进程间通信的一种方式。

API:

int mkfifo(const char *pathname, mode_t mode);

DEMO:

// 写进程int main(int argc, char **argv) {    char filename[] = "/tmp/my_fifo";    if (mkfifo(filename, 0777) < 0) {        perror("mkfifo error");        exit(1);    }    int fd = open(filename, O_WRONLY);    char buffer[128] = "hello world";    write(fd, buffer, strlen(buffer));    printf("write done\n");    return 0;}// 读进程int main(int argc, char **argv) {    char filename[] = "/tmp/my_fifo";    int fd = open(filename, O_RDONLY);    char buffer[128];    int n = read(fd, buffer, 128);    buffer[n] = '\0';    printf("input is : %s\n", buffer);    return 0;}

两个地方需要注意：

1. mkfifo会在/tmp目录下创建文件my_fifo

2. 读进程open之前，写进程被阻塞

   (it has to be open at both ends simultaneously before you can proceed to do any input or output operations on it.)

 

与相比，命名管道可用于任意两个进程间的通信。