+++ /dev/null
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-.TH MQ_RECEIVE 3 2014-06-03 "Linux" "Linux Programmer's Manual"
-.SH NAME
-mq_receive, mq_timedreceive \- receive a message from a message queue
-.SH SYNOPSIS
-.nf
-.B #include <mqueue.h>
-.sp
-.BI "ssize_t mq_receive(mqd_t " mqdes ", char *" msg_ptr ,
-.BI " size_t " msg_len ", unsigned int *" msg_prio );
-.sp
-.B #include <time.h>
-.B #include <mqueue.h>
-.sp
-.BI "ssize_t mq_timedreceive(mqd_t " mqdes ", char *" msg_ptr ,
-.BI " size_t " msg_len ", unsigned int *" msg_prio ,
-.BI " const struct timespec *" abs_timeout );
-.fi
-.sp
-Link with \fI\-lrt\fP.
-.sp
-.ad l
-.in -4n
-Feature Test Macro Requirements for glibc (see
-.BR feature_test_macros (7)):
-.in
-.sp
-.BR mq_timedreceive ():
-.RS 4
-_XOPEN_SOURCE\ >=\ 600 || _POSIX_C_SOURCE\ >=\ 200112L
-.RE
-.ad
-.SH DESCRIPTION
-.BR mq_receive ()
-removes the oldest message with the highest priority from
-the message queue referred to by the descriptor
-.IR mqdes ,
-and places it in the buffer pointed to by
-.IR msg_ptr .
-The
-.I msg_len
-argument specifies the size of the buffer pointed to by
-.IR msg_ptr ;
-this must be greater than or equal to the
-.I mq_msgsize
-attribute of the queue (see
-.BR mq_getattr (3)).
-If
-.I msg_prio
-is not NULL, then the buffer to which it points is used
-to return the priority associated with the received message.
-
-If the queue is empty, then, by default,
-.BR mq_receive ()
-blocks until a message becomes available,
-or the call is interrupted by a signal handler.
-If the
-.B O_NONBLOCK
-flag is enabled for the message queue description,
-then the call instead fails immediately with the error
-.BR EAGAIN .
-
-.BR mq_timedreceive ()
-behaves just like
-.BR mq_receive (),
-except that if the queue is empty and the
-.B O_NONBLOCK
-flag is not enabled for the message queue description, then
-.I abs_timeout
-points to a structure which specifies a ceiling on the time for which
-the call will block.
-This ceiling is an absolute timeout in seconds and nanoseconds
-since the Epoch, 1970-01-01 00:00:00 +0000 (UTC), and it is
-specified in the following structure:
-.sp
-.in +4n
-.nf
-struct timespec {
- time_t tv_sec; /* seconds */
- long tv_nsec; /* nanoseconds */
-};
-
-.fi
-.in
-If no message is available,
-and the timeout has already expired by the time of the call,
-.BR mq_timedreceive ()
-returns immediately.
-.SH RETURN VALUE
-On success,
-.BR mq_receive ()
-and
-.BR mq_timedreceive ()
-return the number of bytes in the received message;
-on error, \-1 is returned, with
-.I errno
-set to indicate the error.
-.SH ERRORS
-.TP
-.B EAGAIN
-The queue was empty, and the
-.B O_NONBLOCK
-flag was set for the message queue description referred to by
-.IR mqdes .
-.TP
-.B EBADF
-The descriptor specified in
-.I mqdes
-was invalid.
-.TP
-.B EINTR
-The call was interrupted by a signal handler; see
-.BR signal (7).
-.TP
-.B EINVAL
-The call would have blocked, and
-.I abs_timeout
-was invalid, either because
-.I tv_sec
-was less than zero, or because
-.I tv_nsec
-was less than zero or greater than 1000 million.
-.TP
-.B EMSGSIZE
-.I msg_len
-was less than the
-.I mq_msgsize
-attribute of the message queue.
-.TP
-.B ETIMEDOUT
-The call timed out before a message could be transferred.
-.SH ATTRIBUTES
-.SS Multithreading (see pthreads(7))
-The
-.BR mq_receive ()
-and
-.BR mq_timedreceive ()
-functions are thread-safe.
-.SH CONFORMING TO
-POSIX.1-2001.
-.SH NOTES
-On Linux,
-.BR mq_timedreceive ()
-is a system call, and
-.BR mq_receive ()
-is a library function layered on top of that system call.
-.SH SEE ALSO
-.BR mq_close (3),
-.BR mq_getattr (3),
-.BR mq_notify (3),
-.BR mq_open (3),
-.BR mq_send (3),
-.BR mq_unlink (3),
-.BR mq_overview (7),
-.BR time (7)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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