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Top Forums Programming POSIX message queue mq_open directory Post 302653773 by anpufeng on Sunday 10th of June 2012 10:17:34 AM
Old 06-10-2012
Quote:
Originally Posted by Corona688
As far as I know message queues aren't real files. They can be in some implementations but there's no need for them to be, and often aren't. So the name only has meaning to the kernel.
thanks, I have found it out, I can use the command
sudo mount -t mqueue none des-dir
to mount to the file system, the "mqueue-files" I created can be found there.Smilie
 

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MQ_CLOSE(2)						      BSD System Calls Manual						       MQ_CLOSE(2)

NAME
mq_close -- close a message queue (REALTIME) LIBRARY
POSIX Real-time Library (librt, -lrt) SYNOPSIS
#include <mqueue.h> int mq_close(mqd_t mqdes); DESCRIPTION
The mq_close() system call 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 sub- sequent mq_open(), are undefined. If the process has successfully attached a notification request to the message queue via this mqdes, this attachment will be removed, and the message queue is available for another process to attach for notification. RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error. ERRORS
The mq_close() system call will fail if: [EBADF] The mqdes argument is not a valid message queue descriptor. SEE ALSO
mq_open(2), mq_unlink(2) STANDARDS
The mq_close() system call conforms to IEEE Std 1003.1-2004 (``POSIX.1''). HISTORY
Support for POSIX message queues first appeared in FreeBSD 7.0. COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Elec- trical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html. BSD
November 29, 2005 BSD
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