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

13       mq_setattr — set message queue attributes (REALTIME)
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SYNOPSIS

16       #include <mqueue.h>
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18       int mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat,
19           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    The value of this member is the bitwise-logical OR of  zero
31                   or more of O_NONBLOCK and any implementation-defined flags.
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33       The  values of the mq_maxmsg, mq_msgsize, and mq_curmsgs members of the
34       mq_attr structure shall be ignored by mq_setattr().
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36       If omqstat is non-NULL, the mq_setattr() function shall store,  in  the
37       location  referenced  by omqstat, the previous message queue attributes
38       and the current queue status.  These values shall be the same as  would
39       be returned by a call to mq_getattr() at that point.
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RETURN VALUE

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

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

58       None.
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APPLICATION USAGE

61       None.
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RATIONALE

64       None.
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FUTURE DIRECTIONS

67       None.
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SEE ALSO

70       mq_open(), mq_send(), msgctl(), msgget(), msgrcv(), msgsnd()
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72       The Base Definitions volume of POSIX.1‐2008, <mqueue.h>
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75       Portions  of  this text are reprinted and reproduced in electronic form
76       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
77       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
78       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
79       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
80       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  In  the
81       event of any discrepancy between this version and the original IEEE and
82       The Open Group Standard, the original IEEE and The Open Group  Standard
83       is  the  referee document. The original Standard can be obtained online
84       at http://www.unix.org/online.html .
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86       Any typographical or formatting errors that appear  in  this  page  are
87       most likely to have been introduced during the conversion of the source
88       files to man page format. To report such errors,  see  https://www.ker‐
89       nel.org/doc/man-pages/reporting_bugs.html .
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93IEEE/The Open Group                  2013                       MQ_SETATTR(3P)
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