mq_setattr

Langue: en

Version: DECEMBER 2002 (mandriva - 01/05/08)

Autres sections - même nom

Section: 2 (Appels système)

Sommaire

NAME

mq_setattr - set/get message queue attributes

SYNOPSIS

gcc [ flag... ] file ... -lmqueue [ library... ]

#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 is used to set 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 are set to the specified values upon successful completion of mq_setattr():

mq_flags
The value of this member is either 0 or O_NONBLOCK.

The values of mq_maxmsg, mq_msgsize, and mq_curmsgs are ignored by mq_setattr().

If omqstat is non-NULL, mq_setattr() stores, 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() at that point.

RETURN VALUES

Upon successful completion, mq_setattr() returns 0 and the attributes of the message queue will have been changed as specified. Otherwise, the message queue attributes are unchanged, and the function returns -1 and sets errno to indicate the error.

DIAGNOSTICS

The mq_setattr() function will fail if:
EBADF
The mqdes argument is not a valid message queue descriptor.
EINVAL
The mqstat argument is set to NULL.
EFAULT
mqstat or omqstat points outside your accessible address space.

AUTHORS

Michal Wronski <wrona@mat.uni.torun.pl>
Krzysztof Benedyczak <golbi@mat.uni.torun.pl>

CONFORMING TO

IEEE Std 1003.1-2001

SEE ALSO

mq_getattr(2)