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mq_getattr(3) [netbsd man page]

MQ_GETATTR(3)						   BSD Library Functions Manual 					     MQ_GETATTR(3)

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() function will obtain status information and attributes of the message queue and the open message queue description associ- ated 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 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(3) 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
The mq_getattr() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi- cate the error. ERRORS
The mq_getattr() function may fail if: [EBADF] The mqdes argument is not a valid message queue descriptor. SEE ALSO
mq(3), mq_setattr(3) STANDARDS
This function conforms to the IEEE Std 1003.1-2001 (``POSIX.1'') standard. HISTORY
This function first appeared in NetBSD 5.0. COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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
June 7, 2010 BSD

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MQ_SETATTR(3)						   BSD Library Functions Manual 					     MQ_SETATTR(3)

NAME
mq_setattr -- set message queue attributes (REALTIME) LIBRARY
POSIX Real-time Library (librt, -lrt) SYNOPSIS
#include <mqueue.h> int mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat, struct mq_attr *restrict omqstat); DESCRIPTION
The mq_setattr() function sets attributes associated with the open message queue description referenced by the message queue descriptor spec- ified by mqdes. The message queue attributes corresponding to the following members defined in the mq_attr structure will be set to the specified values upon successful completion of mq_setattr(): mq_flags The value of this member is the bitwise-logical OR of zero or more of O_NONBLOCK and any implementation-defined flags. The values of the mq_maxmsg, mq_msgsize, and mq_curmsgs members of the mq_attr structure will be ignored by mq_setattr(). If omqstat is non-NULL, the mq_setattr() function will store, in the location referenced by omqstat the previous message queue attributes and the current queue status. These values are the same as would be returned by a call to mq_getattr(3) at that point. RETURN VALUES
Upon successful completion, the mq_setattr() function returns zero and the attributes of the message queue will have been changed as speci- fied. Otherwise, the message queue attributes are unchanged, and the function returns a value of -1 and sets the global variable errno to indicate the error. ERRORS
The mq_setattr() function fails if: [EBADF] The mqdes argument is not a valid message queue descriptor. SEE ALSO
mq(3), mq_getattr(3) STANDARDS
This function conforms to the IEEE Std 1003.1-2001 (``POSIX.1'') standard. HISTORY
This function first appeared in NetBSD 5.0. COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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
June 7, 2010 BSD
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