linux - mq_open 错误 : invalid argument

Question

谁能帮我指出我代码中的错误在哪里？
提前谢谢你。

这是我的代码。我删除了下面代码中的头文件。当我运行这些代码时，我总是收到

:mq_open:invalid argument

#define FILE_MODE S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH
struct mq_attr attr;
int main (int argc,char **argv)
{
    int c;
    int flags;
    mqd_t mqd;

    flags = O_RDWR|O_CREAT;

    while ( (c = getopt (argc,argv,"em:z:")) != -1) {
        switch (c) {
            case 'e':
                flags |= O_EXCL;
                continue;

            case 'm':
                attr.mq_maxmsg = atol (optarg);
                break;

            case 'z':
                attr.mq_msgsize = atol (optarg);
                break;
        }
    }

    if (optind != argc - 1) {
        printf ("usage:mqcreate [-e] [-m maxseg -z msgsize] <name>\n");
        exit (1);
    }

    if ((attr.mq_maxmsg != 0 && attr.mq_msgsize == 0) ||
            (attr.mq_maxmsg == 0 && attr.mq_msgsize != 0))
    {
        printf ("must specify both -m maxmsg and -z msgsize\n");
        exit (1);
    }

    if (attr.mq_msgsize == 0 && attr.mq_maxmsg == 0)
    {
        attr.mq_msgsize = 10;
        attr.mq_maxmsg = 10;
    }


    mqd = mq_open (argv[optind],flags,FILE_MODE,&attr);
    if (mqd == -1) {
       perror ("mq_open");
       exit (1);
   }

   mq_close (mqd);

   return 0;
}

我在 stackoverflow 上搜索了这个问题，但没有任何帮助。
谢谢。

Answer 1

./foobar 不是 mq 名称的有效值。 mq_overview man page :

Each message queue is identified by a name of the form /somename; that is, a null-terminated string of up to NAME_MAX (i.e., 255) characters consisting of an initial slash, followed by one or more characters, none of which are slashes.

因此运行名称为 /foobar 而不是 ./foobar 的程序。