Posix消息队列的基本操作——发送消息

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

int main(int argc, char** argv)
{
    mqd_t   mqd;
    void    *ptr;
    size_t  len;
    size_t  prio;

    if(argc != 4)
    {
        printf("usage: mqsend <name> <#bytes> <priority>");
    }
    len = atoi(argv[2]);
    prio = atoi(argv[3]);
    mqd = mq_open(argv[1], O_WRONLY);

    ptr = calloc(len, sizeof(char));

    mq_send(mqd, ptr, len, prio);

    exit(0);
}