1MQ_SETATTR(3P)             POSIX Programmer's Manual            MQ_SETATTR(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       mq_setattr - set message queue attributes (REALTIME)
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SYNOPSIS

15       #include <mqueue.h>
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17       int mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat,
18              struct mq_attr *restrict omqstat);
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DESCRIPTION

22       The mq_setattr() function shall set attributes associated with the open
23       message  queue  description  referenced by the message queue descriptor
24       specified by mqdes.
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26       The message queue attributes corresponding  to  the  following  members
27       defined  in  the mq_attr structure shall be set to the specified values
28       upon successful completion of mq_setattr():
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30       mq_flags
31              The value of this member is the bitwise-logical OR  of  zero  or
32              more of O_NONBLOCK and any implementation-defined flags.
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35       The  values of the mq_maxmsg, mq_msgsize, and mq_curmsgs members of the
36       mq_attr structure shall be ignored by mq_setattr().
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38       If omqstat is non-NULL, the mq_setattr() function shall store,  in  the
39       location  referenced  by omqstat, the previous message queue attributes
40       and the current queue status. These values shall be the same  as  would
41       be returned by a call to mq_getattr() at that point.
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RETURN VALUE

44       Upon  successful  completion, the function shall return a value of zero
45       and the attributes of the message queue  shall  have  been  changed  as
46       specified.
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48       Otherwise,  the  message  queue  attributes shall be unchanged, and the
49       function shall return a value of -1  and  set  errno  to  indicate  the
50       error.
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ERRORS

53       The mq_setattr() function shall fail if:
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55       EBADF  The mqdes argument is not a valid message queue descriptor.
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58       The following sections are informative.
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EXAMPLES

61       None.
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APPLICATION USAGE

64       None.
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RATIONALE

67       None.
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FUTURE DIRECTIONS

70       None.
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SEE ALSO

73       mq_open(),  mq_send(),  mq_timedsend(),  msgctl(),  msgget(), msgrcv(),
74       msgsnd(),  the  Base  Definitions   volume   of   IEEE Std 1003.1-2001,
75       <mqueue.h>
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78       Portions  of  this text are reprinted and reproduced in electronic form
79       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
80       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
81       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
82       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
83       event of any discrepancy between this version and the original IEEE and
84       The  Open Group Standard, the original IEEE and The Open Group Standard
85       is the referee document. The original Standard can be  obtained  online
86       at http://www.opengroup.org/unix/online.html .
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90IEEE/The Open Group                  2003                       MQ_SETATTR(3P)
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