wrfifo.c

基于网络编程的例子

/*
 * wrfifo.c - Write to a "well-known" FIFO
 */
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <limits.h>
#include <time.h>

int main(void)
{
    int fd;			/* Descriptor for FIFO */
    int len;			/* Bytes written to FIFO */
    char buf[PIPE_BUF];	/* Ensure atomic writes */
    time_t tp;			/* For time call */

    /* Identify myself */
    printf("I am %d\n", getpid());

    /* Open the FIFO write-only */
    if((fd = open("fifo1", O_WRONLY)) < 0) {
       perror("open");
       exit(EXIT_FAILURE);
    }

    /* Generate some data to write */
    while(1) {
        /* Get the current time */
        time(&tp);
        /* Create the string to write */
        len = sprintf(buf, "wrfifo %d sends %s", getpid(), ctime(&tp));
        /* 
        * Use (len + 1) because sprintf does not count
        * the terminating null
        */
        if((write(fd, buf, len + 1)) < 0) {
        perror("write");
        close(fd);
        exit(EXIT_FAILURE);
        }
        sleep(3);
    }

    close(fd);
    exit(EXIT_SUCCESS);
}