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mq_getattr(2) [freebsd man page]

MQ_GETATTR(2)						      BSD System Calls Manual						     MQ_GETATTR(2)

NAME
mq_getattr -- get message queue attributes (REALTIME) LIBRARY
POSIX Real-time Library (librt, -lrt) SYNOPSIS
#include <mqueue.h> int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat); DESCRIPTION
The mq_getattr() system call obtains status information and attributes of the message queue and the open message queue description associated with the message queue descriptor. The mqdes argument specifies a message queue descriptor. The results are returned in the mq_attr structure referenced by the mqstat argument. Upon return, the following members will have the values associated with the open message queue description as set when the message queue was opened and as modified by subsequent mq_setattr() calls: mq_flags. The following attributes of the message queue will be returned as set at message queue creation: mq_maxmsg, mq_msgsize. Upon return, the following members within the mq_attr structure referenced by the mqstat argument will be set to the current state of the message queue: mq_curmsgs The number of messages currently on the queue. 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_getattr() system call will fail if: [EBADF] The mqdes argument is not a valid message queue descriptor. SEE ALSO
mq_open(2), mq_send(2), mq_setattr(2), mq_timedsend(2) STANDARDS
The mq_getattr() 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
February 21, 2014 BSD

Check Out this Related Man Page

MQ_GETATTR(3P)						     POSIX Programmer's Manual						    MQ_GETATTR(3P)

PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
mq_getattr - get message queue attributes (REALTIME) SYNOPSIS
#include <mqueue.h> int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat); DESCRIPTION
The mq_getattr() function shall obtain status information and attributes of the message queue and the open message queue description asso- ciated with the message queue descriptor. The mqdes argument specifies a message queue descriptor. The results shall be returned in the mq_attr structure referenced by the mqstat argument. Upon return, the following members shall have the values associated with the open message queue description as set when the message queue was opened and as modified by subsequent mq_setattr() calls: mq_flags. The following attributes of the message queue shall be returned as set at message queue creation: mq_maxmsg, mq_msgsize. Upon return, the following members within the mq_attr structure referenced by the mqstat argument shall be set to the current state of the message queue: mq_curmsgs The number of messages currently on the queue. RETURN VALUE
Upon successful completion, the mq_getattr() function shall return zero. Otherwise, the function shall return -1 and set errno to indicate the error. ERRORS
The mq_getattr() function shall fail if: EBADF The mqdes argument is not a valid message queue descriptor. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
None. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
mq_open(), mq_send(), mq_setattr(), mq_timedsend(), msgctl(), msgget(), msgrcv(), msgsnd(), the Base Definitions volume of IEEE Std 1003.1-2001, <mqueue.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical 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 . IEEE
/The Open Group 2003 MQ_GETATTR(3P)

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