You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
123 lines
4.2 KiB
123 lines
4.2 KiB
6 years ago
|
'\" t
|
||
|
|
.\" Title: zmq_recv
|
||
|
|
.\" Author: [see the "AUTHORS" section]
|
||
|
|
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
|
||
|
|
.\" Date: 09/14/2016
|
||
|
|
.\" Manual: 0MQ Manual
|
||
|
|
.\" Source: 0MQ 4.1.5
|
||
|
|
.\" Language: English
|
||
|
|
.\"
|
||
|
|
.TH "ZMQ_RECV" "3" "09/14/2016" "0MQ 4\&.1\&.5" "0MQ Manual"
|
||
|
|
.\" -----------------------------------------------------------------
|
||
|
|
.\" * Define some portability stuff
|
||
|
|
.\" -----------------------------------------------------------------
|
||
|
|
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
.\" http://bugs.debian.org/507673
|
||
|
|
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
|
||
|
|
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
.ie \n(.g .ds Aq \(aq
|
||
|
|
.el .ds Aq '
|
||
|
|
.\" -----------------------------------------------------------------
|
||
|
|
.\" * set default formatting
|
||
|
|
.\" -----------------------------------------------------------------
|
||
|
|
.\" disable hyphenation
|
||
|
|
.nh
|
||
|
|
.\" disable justification (adjust text to left margin only)
|
||
|
|
.ad l
|
||
|
|
.\" -----------------------------------------------------------------
|
||
|
|
.\" * MAIN CONTENT STARTS HERE *
|
||
|
|
.\" -----------------------------------------------------------------
|
||
|
|
.SH "NAME"
|
||
|
|
zmq_recv \- receive a message part from a socket
|
||
|
|
.SH "SYNOPSIS"
|
||
|
|
.sp
|
||
|
|
\fBint zmq_recv (void \fR\fB\fI*socket\fR\fR\fB, void \fR\fB\fI*buf\fR\fR\fB, size_t \fR\fB\fIlen\fR\fR\fB, int \fR\fB\fIflags\fR\fR\fB);\fR
|
||
|
|
.SH "DESCRIPTION"
|
||
|
|
.sp
|
||
|
|
The \fIzmq_recv()\fR function shall receive a message from the socket referenced by the \fIsocket\fR argument and store it in the buffer referenced by the \fIbuf\fR argument\&. Any bytes exceeding the length specified by the \fIlen\fR argument shall be truncated\&. If there are no messages available on the specified \fIsocket\fR the \fIzmq_recv()\fR function shall block until the request can be satisfied\&. The \fIflags\fR argument is a combination of the flags defined below:
|
||
|
|
.PP
|
||
|
|
\fBZMQ_DONTWAIT\fR
|
||
|
|
.RS 4
|
||
|
|
Specifies that the operation should be performed in non\-blocking mode\&. If there are no messages available on the specified
|
||
|
|
\fIsocket\fR, the
|
||
|
|
\fIzmq_recv()\fR
|
||
|
|
function shall fail with
|
||
|
|
\fIerrno\fR
|
||
|
|
set to EAGAIN\&.
|
||
|
|
.RE
|
||
|
|
.SS "Multi\-part messages"
|
||
|
|
.sp
|
||
|
|
A 0MQ message is composed of 1 or more message parts\&. 0MQ ensures atomic delivery of messages: peers shall receive either all \fImessage parts\fR of a message or none at all\&. The total number of message parts is unlimited except by available memory\&.
|
||
|
|
.sp
|
||
|
|
An application that processes multi\-part messages must use the \fIZMQ_RCVMORE\fR \fBzmq_getsockopt\fR(3) option after calling \fIzmq_recv()\fR to determine if there are further parts to receive\&.
|
||
|
|
.SH "RETURN VALUE"
|
||
|
|
.sp
|
||
|
|
The \fIzmq_recv()\fR function shall return number of bytes in the message if successful\&. Note that the value can exceed the value of the \fIlen\fR parameter in case the message was truncated\&. If not successful the function shall return \-1 and set \fIerrno\fR to one of the values defined below\&.
|
||
|
|
.SH "ERRORS"
|
||
|
|
.PP
|
||
|
|
\fBEAGAIN\fR
|
||
|
|
.RS 4
|
||
|
|
Non\-blocking mode was requested and no messages are available at the moment\&.
|
||
|
|
.RE
|
||
|
|
.PP
|
||
|
|
\fBENOTSUP\fR
|
||
|
|
.RS 4
|
||
|
|
The
|
||
|
|
\fIzmq_recv()\fR
|
||
|
|
operation is not supported by this socket type\&.
|
||
|
|
.RE
|
||
|
|
.PP
|
||
|
|
\fBEFSM\fR
|
||
|
|
.RS 4
|
||
|
|
The
|
||
|
|
\fIzmq_recv()\fR
|
||
|
|
operation cannot be performed on this socket at the moment due to the socket not being in the appropriate state\&. This error may occur with socket types that switch between several states, such as ZMQ_REP\&. See the
|
||
|
|
\fImessaging patterns\fR
|
||
|
|
section of
|
||
|
|
\fBzmq_socket\fR(3)
|
||
|
|
for more information\&.
|
||
|
|
.RE
|
||
|
|
.PP
|
||
|
|
\fBETERM\fR
|
||
|
|
.RS 4
|
||
|
|
The 0MQ
|
||
|
|
\fIcontext\fR
|
||
|
|
associated with the specified
|
||
|
|
\fIsocket\fR
|
||
|
|
was terminated\&.
|
||
|
|
.RE
|
||
|
|
.PP
|
||
|
|
\fBENOTSOCK\fR
|
||
|
|
.RS 4
|
||
|
|
The provided
|
||
|
|
\fIsocket\fR
|
||
|
|
was invalid\&.
|
||
|
|
.RE
|
||
|
|
.PP
|
||
|
|
\fBEINTR\fR
|
||
|
|
.RS 4
|
||
|
|
The operation was interrupted by delivery of a signal before a message was available\&.
|
||
|
|
.RE
|
||
|
|
.SH "EXAMPLE"
|
||
|
|
.PP
|
||
|
|
\fBReceiving a message from a socket\fR.
|
||
|
|
.sp
|
||
|
|
.if n \{\
|
||
|
|
.RS 4
|
||
|
|
.\}
|
||
|
|
.nf
|
||
|
|
char buf [256];
|
||
|
|
nbytes = zmq_recv (socket, buf, 256, 0);
|
||
|
|
assert (nbytes != \-1);
|
||
|
|
.fi
|
||
|
|
.if n \{\
|
||
|
|
.RE
|
||
|
|
.\}
|
||
|
|
.sp
|
||
|
|
.SH "SEE ALSO"
|
||
|
|
.sp
|
||
|
|
\fBzmq_send\fR(3) \fBzmq_getsockopt\fR(3) \fBzmq_socket\fR(7) \fBzmq\fR(7)
|
||
|
|
.SH "AUTHORS"
|
||
|
|
.sp
|
||
|
|
This page was written by the 0MQ community\&. To make a change please read the 0MQ Contribution Policy at \m[blue]\fBhttp://www\&.zeromq\&.org/docs:contributing\fR\m[]\&.
|