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Full Discussion: POSIX message queue mq_open directory
Top Forums Programming POSIX message queue mq_open directory Post 302653451 by anpufeng on Saturday 9th of June 2012 03:13:59 AM
Old 06-09-2012
POSIX message queue mq_open directory
hello, I try to test the POSIX mq_open function on book unp like below:
Code:
#include "unpipc.h"
# include    <mqueue.h>

int main(int argc, char **argv)
{
    int        c, flags;
    mqd_t    mqd;

    flags = O_RDWR | O_CREAT;

    while ((c = getopt(argc, argv, "e")) != -1) {
        switch (c) {
        case 'e':
            flags |= O_EXCL;
            break;
        }
    }
    printf("optind = %d,argc = %d\n",optind,argc);
    printf("argv[optiond]: %s\n", argv[optind]);
    if (optind != argc -1)
        err_quit("usage: mqcreate [ - e ] <name>");

    if ((mqd = mq_open(argv[optind], flags, FILE_MODE, NULL)) < 0) {
        printf( "strerror says open failed: %s\n",strerror(errno));
        err_quit("create mqueue failed!\n");
    }
    else
        printf("create mqueue successful\n");
    mq_close(mqd);
    exit(0);
}

./a.out /test.1234
It works ok but I can't find where is the created mq-file(test.1234)? Does anybody know the default directory? thanks.
I am using ubuntu 10.04
 

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LEARN ABOUT SUNOS

mq_close

mq_close(3RT)						    Realtime Library Functions						     mq_close(3RT)

NAME

       mq_close - close a message queue

SYNOPSIS

       cc [ flag... ] file... -lrt [ library... ]
       #include <mqueue.h>

       int mq_close(mqd_t mqdes);

DESCRIPTION

       The  mq_close()	function  removes the association between the message queue descriptor, mqdes, and its message queue. The results of using
       this message queue descriptor after successful return from this mq_close(), and until the return of this message queue  descriptor  from  a
       subsequent mq_open(3RT), are undefined.

       If the process (or thread) has successfully attached a notification request to the message queue via this mqdes, this attachment is removed
       and the message queue is available for another process to attach for notification.

RETURN VALUES

       Upon successful completion, mq_close() returns 0; otherwise, the function returns -1 and sets errno to indicate the error condition.

ERRORS

       The  mq_close() function will fail if:

       EBADF	       The mqdes argument is an invalid message queue descriptor.

       ENOSYS	       The mq_open() function is not supported by the system.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       mqueue.h(3HEAD), mq_notify(3RT), mq_open(3RT), mq_unlink(3RT), attributes(5), standards(5)

NOTES

       Solaris 2.6 was the first release to support the Asynchronous Input and Output option. Prior to this release, this function always returned
       -1 and set errno to ENOSYS.

SunOS 5.10							    28 Jun 2002 						     mq_close(3RT)
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