notes/snippet/cpp/ipc/fifo_write.c

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

#define MAX_BUFF 1024
#define FIFO_FILE "fifo_file"

int main(int argc, char **argv) {
    int fd;
    int n, i;
    char buff[MAX_BUFF];
    time_t timestamp;

    printf("I'm process %d\n", getpid());
    if ((fd = open(FIFO_FILE, O_WRONLY)) < 0) {
        printf("Open %s fails\n", FIFO_FILE);
        exit(1);
    }

    for (i = 0; i < 10; i++) {
        time(&timestamp);
        n = sprintf(buff, "Process %d at %s", getpid(), ctime(&timestamp));
        printf("Send msg: %s\n", buff);
        if (write(fd, buff, n+1) < 0) {
            perror("Write fd fails\n");
            close(fd);
            exit(1);
        }

        sleep(1);
    }

    close(fd);
    return 0;
}