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MQ_SETATTR(2) | System Calls Manual | MQ_SETATTR(2) |
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¶
Themq_setattr
() system call sets attributes
associated with the open message queue description referenced by the message
queue descriptor specified 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 zero or
O_NONBLOCK
.
mq_setattr
().
RETURN VALUES¶
Upon successful completion, the function returns a value of zero and the attributes of the message queue will have been changed as specified. 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¶
Themq_setattr
() 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_timedsend(2)STANDARDS¶
Themq_setattr
() 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 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.May 17, 2011 | Debian |