109 lines
2.7 KiB
Groff
109 lines
2.7 KiB
Groff
.\" $NetBSD: mq_setattr.3,v 1.1 2009/01/05 21:19:49 rmind Exp $
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.\"
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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.\"
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.Dd January 5, 2009
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.Dt MQ_SETATTR 3
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.Os
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.Sh NAME
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.Nm mq_setattr
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.Nd set message queue attributes (REALTIME)
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.Sh LIBRARY
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.Lb librt
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.Sh SYNOPSIS
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.In mqueue.h
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.Ft int
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.Fo mq_setattr
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.Fa "mqd_t mqdes"
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.Fa "const struct mq_attr *restrict mqstat"
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.Fa "struct mq_attr *restrict omqstat"
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.Fc
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.Sh DESCRIPTION
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The
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.Fn mq_setattr
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function sets attributes associated with the open message queue
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description referenced by the message queue descriptor specified by
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.Fa mqdes .
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.Pp
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The message queue attributes corresponding to the following members
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defined in the
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.Vt mq_attr
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structure will be set to the specified values upon successful completion of
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.Fn mq_setattr :
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.Bl -tag -width mq_flags
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.It Va mq_flags
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The value of this member is the bitwise-logical OR of zero or more of
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.Dv O_NONBLOCK
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and any implementation-defined flags.
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.El
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.Pp
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The values of the
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.Va mq_maxmsg ,
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.Va mq_msgsize ,
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and
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.Va mq_curmsgs
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members of the
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.Vt mq_attr
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structure will be ignored by
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.Fn mq_setattr .
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.Pp
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If
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.Fa omqstat
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is
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.No non- Ns Dv NULL ,
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the
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.Fn mq_setattr
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function will store, in the location referenced by
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.Fa omqstat
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the previous message queue attributes and the current queue status.
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These values are the same as would be returned by a call to
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.Xr mq_getattr 3
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at that point.
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.Sh RETURN VALUES
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Upon successful completion, the
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.Fn mq_setattr
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function returns zero and the attributes of the message queue will
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have been changed as specified.
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Otherwise, the message queue attributes are unchanged,
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and the function returns a value of
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\-1 and sets the global variable
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.Va errno
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to indicate the error.
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.Sh ERRORS
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The
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.Fn mq_setattr
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function fails if:
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.Bl -tag -width Er
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.It Bq Er EBADF
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The
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.Fa mqdes
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argument is not a valid message queue descriptor.
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.El
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.Sh SEE ALSO
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.Xr mq_close 3 ,
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.Xr mq_getattr 3 ,
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.Xr mq_notify 3 ,
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.Xr mq_open 3 ,
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.Xr mq_receive 3 ,
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.Xr mq_send 3 ,
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.Xr mq_unlink 3
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.Sh STANDARDS
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This function conforms to the
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.St -p1003.1-2001
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standard.
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.Sh HISTORY
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This function first appeared in
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.Nx 5.0 .
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.Sh COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group.
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In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document.
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The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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