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							1879 lines
						
					
					
						
							31 KiB
						
					
					
				'\" t
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.\"     Title: zmq_getsockopt
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.\"    Author: [see the "AUTHORS" section]
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.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
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.\"      Date: 09/14/2016
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.\"    Manual: 0MQ Manual
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.\"    Source: 0MQ 4.1.5
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.\"  Language: English
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.\"
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.TH "ZMQ_GETSOCKOPT" "3" "09/14/2016" "0MQ 4\&.1\&.5" "0MQ Manual"
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.\" -----------------------------------------------------------------
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.\" * Define some portability stuff
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.\" -----------------------------------------------------------------
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.\" http://bugs.debian.org/507673
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.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.ie \n(.g .ds Aq \(aq
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.el       .ds Aq '
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.\" -----------------------------------------------------------------
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.\" * set default formatting
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.\" -----------------------------------------------------------------
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.\" disable hyphenation
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.nh
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.\" disable justification (adjust text to left margin only)
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.ad l
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.\" -----------------------------------------------------------------
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.\" * MAIN CONTENT STARTS HERE *
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.\" -----------------------------------------------------------------
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.SH "NAME"
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zmq_getsockopt \- get 0MQ socket options
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.SH "SYNOPSIS"
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.sp
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\fBint zmq_getsockopt (void \fR\fB\fI*socket\fR\fR\fB, int \fR\fB\fIoption_name\fR\fR\fB, void \fR\fB\fI*option_value\fR\fR\fB, size_t \fR\fB\fI*option_len\fR\fR\fB);\fR
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.SH "DESCRIPTION"
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.sp
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						|
The \fIzmq_getsockopt()\fR function shall retrieve the value for the option specified by the \fIoption_name\fR argument for the 0MQ socket pointed to by the \fIsocket\fR argument, and store it in the buffer pointed to by the \fIoption_value\fR argument\&. The \fIoption_len\fR argument is the size in bytes of the buffer pointed to by \fIoption_value\fR; upon successful completion \fIzmq_getsockopt()\fR shall modify the \fIoption_len\fR argument to indicate the actual size of the option value stored in the buffer\&.
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						|
.sp
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The following options can be retrieved with the \fIzmq_getsockopt()\fR function:
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						|
.SS "ZMQ_AFFINITY: Retrieve I/O thread affinity"
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						|
.sp
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						|
The \fIZMQ_AFFINITY\fR option shall retrieve the I/O thread affinity for newly created connections on the specified \fIsocket\fR\&.
 | 
						|
.sp
 | 
						|
Affinity determines which threads from the 0MQ I/O thread pool associated with the socket\(cqs \fIcontext\fR shall handle newly created connections\&. A value of zero specifies no affinity, meaning that work shall be distributed fairly among all 0MQ I/O threads in the thread pool\&. For non\-zero values, the lowest bit corresponds to thread 1, second lowest bit to thread 2 and so on\&. For example, a value of 3 specifies that subsequent connections on \fIsocket\fR shall be handled exclusively by I/O threads 1 and 2\&.
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						|
.sp
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						|
See also \fBzmq_init\fR(3) for details on allocating the number of I/O threads for a specific \fIcontext\fR\&.
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						|
.TS
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tab(:);
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lt lt
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lt lt
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lt lt
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lt lt.
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						|
T{
 | 
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.sp
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						|
Option value type
 | 
						|
T}:T{
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						|
.sp
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						|
uint64_t
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
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						|
.sp
 | 
						|
N/A (bitmap)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
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						|
.sp
 | 
						|
0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_BACKLOG: Retrieve maximum length of the queue of outstanding connections"
 | 
						|
.sp
 | 
						|
The \fIZMQ_BACKLOG\fR option shall retrieve the maximum length of the queue of outstanding peer connections for the specified \fIsocket\fR; this only applies to connection\-oriented transports\&. For details refer to your operating system documentation for the \fIlisten\fR function\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
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						|
lt lt
 | 
						|
lt lt
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						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
connections
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
100
 | 
						|
T}
 | 
						|
T{
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						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
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						|
all, only for connection\-oriented transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
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						|
.SS "ZMQ_CURVE_PUBLICKEY: Retrieve current CURVE public key"
 | 
						|
.sp
 | 
						|
Retrieves the current long term public key for the socket\&. You can provide either a 32 byte buffer, to retrieve the binary key value, or a 41 byte buffer, to retrieve the key in a printable Z85 format\&. NOTE: to fetch a printable key, the buffer must be 41 bytes large to hold the 40\-char key value and one null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
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						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
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						|
.sp
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						|
binary data or Z85 text string
 | 
						|
T}
 | 
						|
T{
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						|
.sp
 | 
						|
Option value size
 | 
						|
T}:T{
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						|
.sp
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						|
32 or 41
 | 
						|
T}
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						|
T{
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						|
.sp
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						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transport
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_CURVE_SECRETKEY: Retrieve current CURVE secret key"
 | 
						|
.sp
 | 
						|
Retrieves the current long term secret key for the socket\&. You can provide either a 32 byte buffer, to retrieve the binary key value, or a 41 byte buffer, to retrieve the key in a printable Z85 format\&. NOTE: to fetch a printable key, the buffer must be 41 bytes large to hold the 40\-char key value and one null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
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						|
lt lt
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						|
lt lt
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						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
binary data or Z85 text string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value size
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
32 or 41
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transport
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_CURVE_SERVERKEY: Retrieve current CURVE server key"
 | 
						|
.sp
 | 
						|
Retrieves the current server key for the client socket\&. You can provide either a 32 byte buffer, to retrieve the binary key value, or a 41\-byte buffer, to retrieve the key in a printable Z85 format\&. NOTE: to fetch a printable key, the buffer must be 41 bytes large to hold the 40\-char key value and one null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
binary data or Z85 text string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value size
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
32 or 41
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transport
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_EVENTS: Retrieve socket event state"
 | 
						|
.sp
 | 
						|
The \fIZMQ_EVENTS\fR option shall retrieve the event state for the specified \fIsocket\fR\&. The returned value is a bit mask constructed by OR\(cqing a combination of the following event flags:
 | 
						|
.PP
 | 
						|
\fBZMQ_POLLIN\fR
 | 
						|
.RS 4
 | 
						|
Indicates that at least one message may be received from the specified socket without blocking\&.
 | 
						|
.RE
 | 
						|
.PP
 | 
						|
\fBZMQ_POLLOUT\fR
 | 
						|
.RS 4
 | 
						|
Indicates that at least one message may be sent to the specified socket without blocking\&.
 | 
						|
.RE
 | 
						|
.sp
 | 
						|
The combination of a file descriptor returned by the \fIZMQ_FD\fR option being ready for reading but no actual events returned by a subsequent retrieval of the \fIZMQ_EVENTS\fR option is valid; applications should simply ignore this case and restart their polling operation/event loop\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A (flags)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_FD: Retrieve file descriptor associated with the socket"
 | 
						|
.sp
 | 
						|
The \fIZMQ_FD\fR option shall retrieve the file descriptor associated with the specified \fIsocket\fR\&. The returned file descriptor can be used to integrate the socket into an existing event loop; the 0MQ library shall signal any pending events on the socket in an \fIedge\-triggered\fR fashion by making the file descriptor become ready for reading\&.
 | 
						|
.if n \{\
 | 
						|
.sp
 | 
						|
.\}
 | 
						|
.RS 4
 | 
						|
.it 1 an-trap
 | 
						|
.nr an-no-space-flag 1
 | 
						|
.nr an-break-flag 1
 | 
						|
.br
 | 
						|
.ps +1
 | 
						|
\fBNote\fR
 | 
						|
.ps -1
 | 
						|
.br
 | 
						|
.sp
 | 
						|
The ability to read from the returned file descriptor does not necessarily indicate that messages are available to be read from, or can be written to, the underlying socket; applications must retrieve the actual event state with a subsequent retrieval of the \fIZMQ_EVENTS\fR option\&.
 | 
						|
.sp .5v
 | 
						|
.RE
 | 
						|
.if n \{\
 | 
						|
.sp
 | 
						|
.\}
 | 
						|
.RS 4
 | 
						|
.it 1 an-trap
 | 
						|
.nr an-no-space-flag 1
 | 
						|
.nr an-break-flag 1
 | 
						|
.br
 | 
						|
.ps +1
 | 
						|
\fBNote\fR
 | 
						|
.ps -1
 | 
						|
.br
 | 
						|
.sp
 | 
						|
The returned file descriptor is also used internally by the \fIzmq_send\fR and \fIzmq_recv\fR functions\&. As the descriptor is edge triggered, applications must update the state of \fIZMQ_EVENTS\fR after each invocation of \fIzmq_send\fR or \fIzmq_recv\fR\&.To be more explicit: after calling \fIzmq_send\fR the socket may become readable (and vice versa) without triggering a read event on the file descriptor\&.
 | 
						|
.sp .5v
 | 
						|
.RE
 | 
						|
.if n \{\
 | 
						|
.sp
 | 
						|
.\}
 | 
						|
.RS 4
 | 
						|
.it 1 an-trap
 | 
						|
.nr an-no-space-flag 1
 | 
						|
.nr an-break-flag 1
 | 
						|
.br
 | 
						|
.ps +1
 | 
						|
\fBCaution\fR
 | 
						|
.ps -1
 | 
						|
.br
 | 
						|
.sp
 | 
						|
The returned file descriptor is intended for use with a \fIpoll\fR or similar system call only\&. Applications must never attempt to read or write data to it directly, neither should they try to close it\&.
 | 
						|
.sp .5v
 | 
						|
.RE
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int on POSIX systems, SOCKET on Windows
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_GSSAPI_PLAINTEXT: Retrieve GSSAPI plaintext or encrypted status"
 | 
						|
.sp
 | 
						|
Returns the \fIZMQ_GSSAPI_PLAINTEXT\fR option, if any, previously set on the socket\&. A value of \fI1\fR means that communications will be plaintext\&. A value of \fI0\fR means communications will be encrypted\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0, 1
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0 (false)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_GSSAPI_PRINCIPAL: Retrieve the name of the GSSAPI principal"
 | 
						|
.sp
 | 
						|
The \fIZMQ_GSSAPI_PRINCIPAL\fR option shall retrieve the principal name set for the GSSAPI security mechanism\&. The returned value shall be a NULL\-terminated string and MAY be empty\&. The returned size SHALL include the terminating null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL\-terminated character string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_GSSAPI_SERVER: Retrieve current GSSAPI server role"
 | 
						|
.sp
 | 
						|
Returns the \fIZMQ_GSSAPI_SERVER\fR option, if any, previously set on the socket\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0, 1
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0 (false)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_GSSAPI_SERVICE_PRINCIPAL: Retrieve the name of the GSSAPI service principal"
 | 
						|
.sp
 | 
						|
The \fIZMQ_GSSAPI_SERVICE_PRINCIPAL\fR option shall retrieve the principal name of the GSSAPI server to which a GSSAPI client socket intends to connect\&. The returned value shall be a NULL\-terminated string and MAY be empty\&. The returned size SHALL include the terminating null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL\-terminated character string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_HANDSHAKE_IVL: Retrieve maximum handshake interval"
 | 
						|
.sp
 | 
						|
The \fIZMQ_HANDSHAKE_IVL\fR option shall retrieve the maximum handshake interval for the specified \fIsocket\fR\&. Handshaking is the exchange of socket configuration information (socket type, identity, security) that occurs when a connection is first opened, only for connection\-oriented transports\&. If handshaking does not complete within the configured time, the connection shall be closed\&. The value 0 means no handshake time limit\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
30000
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all but ZMQ_STREAM, only for connection\-oriented transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_IDENTITY: Retrieve socket identity"
 | 
						|
.sp
 | 
						|
The \fIZMQ_IDENTITY\fR option shall retrieve the identity of the specified \fIsocket\fR\&. Socket identity is used only by request/reply pattern\&. Namely, it can be used in tandem with ROUTER socket to route messages to the peer with specific identity\&.
 | 
						|
.sp
 | 
						|
Identity should be at least one byte and at most 255 bytes long\&. Identities starting with binary zero are reserved for use by 0MQ infrastructure\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
binary data
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
ZMQ_REP, ZMQ_REQ, ZMQ_ROUTER, ZMQ_DEALER\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_IMMEDIATE: Retrieve attach\-on\-connect value"
 | 
						|
.sp
 | 
						|
Retrieve the state of the attach on connect value\&. If set to 1, will delay the attachment of a pipe on connect until the underlying connection has completed\&. This will cause the socket to block if there are no other connections, but will prevent queues from filling on pipes awaiting connection\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
boolean
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0 (false)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, primarily when using TCP/IPC transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_IPV4ONLY: Retrieve IPv4\-only socket override status"
 | 
						|
.sp
 | 
						|
Retrieve the IPv4\-only option for the socket\&. This option is deprecated\&. Please use the ZMQ_IPV6 option\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
boolean
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
1 (true)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_IPV6: Retrieve IPv6 socket status"
 | 
						|
.sp
 | 
						|
Retrieve the IPv6 option for the socket\&. A value of 1 means IPv6 is enabled on the socket, while 0 means the socket will use only IPv4\&. When IPv6 is enabled the socket will connect to, or accept connections from, both IPv4 and IPv6 hosts\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
boolean
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0 (false)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_LAST_ENDPOINT: Retrieve the last endpoint set"
 | 
						|
.sp
 | 
						|
The \fIZMQ_LAST_ENDPOINT\fR option shall retrieve the last endpoint bound for TCP and IPC transports\&. The returned value will be a string in the form of a ZMQ DSN\&. Note that if the TCP host is INADDR_ANY, indicated by a *, then the returned address will be 0\&.0\&.0\&.0 (for IPv4)\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL\-terminated character string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when binding TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_LINGER: Retrieve linger period for socket shutdown"
 | 
						|
.sp
 | 
						|
The \fIZMQ_LINGER\fR option shall retrieve the linger period for the specified \fIsocket\fR\&. The linger period determines how long pending messages which have yet to be sent to a peer shall linger in memory after a socket is closed with \fBzmq_close\fR(3), and further affects the termination of the socket\(cqs context with \fBzmq_term\fR(3)\&. The following outlines the different behaviours:
 | 
						|
.sp
 | 
						|
.RS 4
 | 
						|
.ie n \{\
 | 
						|
\h'-04'\(bu\h'+03'\c
 | 
						|
.\}
 | 
						|
.el \{\
 | 
						|
.sp -1
 | 
						|
.IP \(bu 2.3
 | 
						|
.\}
 | 
						|
The default value of
 | 
						|
\fI\-1\fR
 | 
						|
specifies an infinite linger period\&. Pending messages shall not be discarded after a call to
 | 
						|
\fIzmq_close()\fR; attempting to terminate the socket\(cqs context with
 | 
						|
\fIzmq_term()\fR
 | 
						|
shall block until all pending messages have been sent to a peer\&.
 | 
						|
.RE
 | 
						|
.sp
 | 
						|
.RS 4
 | 
						|
.ie n \{\
 | 
						|
\h'-04'\(bu\h'+03'\c
 | 
						|
.\}
 | 
						|
.el \{\
 | 
						|
.sp -1
 | 
						|
.IP \(bu 2.3
 | 
						|
.\}
 | 
						|
The value of
 | 
						|
\fI0\fR
 | 
						|
specifies no linger period\&. Pending messages shall be discarded immediately when the socket is closed with
 | 
						|
\fIzmq_close()\fR\&.
 | 
						|
.RE
 | 
						|
.sp
 | 
						|
.RS 4
 | 
						|
.ie n \{\
 | 
						|
\h'-04'\(bu\h'+03'\c
 | 
						|
.\}
 | 
						|
.el \{\
 | 
						|
.sp -1
 | 
						|
.IP \(bu 2.3
 | 
						|
.\}
 | 
						|
Positive values specify an upper bound for the linger period in milliseconds\&. Pending messages shall not be discarded after a call to
 | 
						|
\fIzmq_close()\fR; attempting to terminate the socket\(cqs context with
 | 
						|
\fIzmq_term()\fR
 | 
						|
shall block until either all pending messages have been sent to a peer, or the linger period expires, after which any pending messages shall be discarded\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
\-1 (infinite)
 | 
						|
T}
 | 
						|
T{
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.RE
 | 
						|
.SS "ZMQ_MAXMSGSIZE: Maximum acceptable inbound message size"
 | 
						|
.sp
 | 
						|
The option shall retrieve limit for the inbound messages\&. If a peer sends a message larger than ZMQ_MAXMSGSIZE it is disconnected\&. Value of \-1 means \fIno limit\fR\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int64_t
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
bytes
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_MECHANISM: Retrieve current security mechanism"
 | 
						|
.sp
 | 
						|
The \fIZMQ_MECHANISM\fR option shall retrieve the current security mechanism for the socket\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
ZMQ_NULL, ZMQ_PLAIN, ZMQ_CURVE, or ZMQ_GSSAPI
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
ZMQ_NULL
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_MULTICAST_HOPS: Maximum network hops for multicast packets"
 | 
						|
.sp
 | 
						|
The option shall retrieve time\-to\-live used for outbound multicast packets\&. The default of 1 means that the multicast packets don\(cqt leave the local network\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
network hops
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
1
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using multicast transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_PLAIN_PASSWORD: Retrieve current password"
 | 
						|
.sp
 | 
						|
The \fIZMQ_PLAIN_PASSWORD\fR option shall retrieve the last password set for the PLAIN security mechanism\&. The returned value shall be a NULL\-terminated string and MAY be empty\&. The returned size SHALL include the terminating null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL\-terminated character string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_PLAIN_SERVER: Retrieve current PLAIN server role"
 | 
						|
.sp
 | 
						|
Returns the \fIZMQ_PLAIN_SERVER\fR option, if any, previously set on the socket\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0, 1
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_PLAIN_USERNAME: Retrieve current PLAIN username"
 | 
						|
.sp
 | 
						|
The \fIZMQ_PLAIN_USERNAME\fR option shall retrieve the last username set for the PLAIN security mechanism\&. The returned value shall be a NULL\-terminated string and MAY be empty\&. The returned size SHALL include the terminating null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
NULL\-terminated character string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
null string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP or IPC transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RATE: Retrieve multicast data rate"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RATE\fR option shall retrieve the maximum send or receive data rate for multicast transports using the specified \fIsocket\fR\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
kilobits per second
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
100
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using multicast transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RCVBUF: Retrieve kernel receive buffer size"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RCVBUF\fR option shall retrieve the underlying kernel receive buffer size for the specified \fIsocket\fR\&. A value of zero means that the OS default is in effect\&. For details refer to your operating system documentation for the \fISO_RCVBUF\fR socket option\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
bytes
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RCVHWM: Retrieve high water mark for inbound messages"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RCVHWM\fR option shall return the high water mark for inbound messages on the specified \fIsocket\fR\&. The high water mark is a hard limit on the maximum number of outstanding messages 0MQ shall queue in memory for any single peer that the specified \fIsocket\fR is communicating with\&. A value of zero means no limit\&.
 | 
						|
.sp
 | 
						|
If this limit has been reached the socket shall enter an exceptional state and depending on the socket type, 0MQ shall take appropriate action such as blocking or dropping sent messages\&. Refer to the individual socket descriptions in \fBzmq_socket\fR(3) for details on the exact action taken for each socket type\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
messages
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
1000
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RCVMORE: More message data parts to follow"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RCVMORE\fR option shall return True (1) if the message part last received from the \fIsocket\fR was a data part with more parts to follow\&. If there are no data parts to follow, this option shall return False (0)\&.
 | 
						|
.sp
 | 
						|
Refer to \fBzmq_send\fR(3) and \fBzmq_recv\fR(3) for a detailed description of multi\-part messages\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
boolean
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RCVTIMEO: Maximum time before a socket operation returns with EAGAIN"
 | 
						|
.sp
 | 
						|
Retrieve the timeout for recv operation on the socket\&. If the value is 0, \fIzmq_recv(3)\fR will return immediately, with a EAGAIN error if there is no message to receive\&. If the value is \-1, it will block until a message is available\&. For all other values, it will wait for a message for that amount of time before returning with an EAGAIN error\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1 (infinite)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RECONNECT_IVL: Retrieve reconnection interval"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RECONNECT_IVL\fR option shall retrieve the initial reconnection interval for the specified \fIsocket\fR\&. The reconnection interval is the period 0MQ shall wait between attempts to reconnect disconnected peers when using connection\-oriented transports\&. The value \-1 means no reconnection\&.
 | 
						|
.if n \{\
 | 
						|
.sp
 | 
						|
.\}
 | 
						|
.RS 4
 | 
						|
.it 1 an-trap
 | 
						|
.nr an-no-space-flag 1
 | 
						|
.nr an-break-flag 1
 | 
						|
.br
 | 
						|
.ps +1
 | 
						|
\fBNote\fR
 | 
						|
.ps -1
 | 
						|
.br
 | 
						|
.sp
 | 
						|
The reconnection interval may be randomized by 0MQ to prevent reconnection storms in topologies with a large number of peers per socket\&.
 | 
						|
.sp .5v
 | 
						|
.RE
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
100
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, only for connection\-oriented transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RECONNECT_IVL_MAX: Retrieve maximum reconnection interval"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RECONNECT_IVL_MAX\fR option shall retrieve the maximum reconnection interval for the specified \fIsocket\fR\&. This is the maximum period 0MQ shall wait between attempts to reconnect\&. On each reconnect attempt, the previous interval shall be doubled untill ZMQ_RECONNECT_IVL_MAX is reached\&. This allows for exponential backoff strategy\&. Default value means no exponential backoff is performed and reconnect interval calculations are only based on ZMQ_RECONNECT_IVL\&.
 | 
						|
.if n \{\
 | 
						|
.sp
 | 
						|
.\}
 | 
						|
.RS 4
 | 
						|
.it 1 an-trap
 | 
						|
.nr an-no-space-flag 1
 | 
						|
.nr an-break-flag 1
 | 
						|
.br
 | 
						|
.ps +1
 | 
						|
\fBNote\fR
 | 
						|
.ps -1
 | 
						|
.br
 | 
						|
.sp
 | 
						|
Values less than ZMQ_RECONNECT_IVL will be ignored\&.
 | 
						|
.sp .5v
 | 
						|
.RE
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0 (only use ZMQ_RECONNECT_IVL)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, only for connection\-oriented transport
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_RECOVERY_IVL: Get multicast recovery interval"
 | 
						|
.sp
 | 
						|
The \fIZMQ_RECOVERY_IVL\fR option shall retrieve the recovery interval for multicast transports using the specified \fIsocket\fR\&. The recovery interval determines the maximum time in milliseconds that a receiver can be absent from a multicast group before unrecoverable data loss will occur\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
10000
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using multicast transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_SNDBUF: Retrieve kernel transmit buffer size"
 | 
						|
.sp
 | 
						|
The \fIZMQ_SNDBUF\fR option shall retrieve the underlying kernel transmit buffer size for the specified \fIsocket\fR\&. A value of zero means that the OS default is in effect\&. For details refer to your operating system documentation for the \fISO_SNDBUF\fR socket option\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
bytes
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_SNDHWM: Retrieves high water mark for outbound messages"
 | 
						|
.sp
 | 
						|
The \fIZMQ_SNDHWM\fR option shall return the high water mark for outbound messages on the specified \fIsocket\fR\&. The high water mark is a hard limit on the maximum number of outstanding messages 0MQ shall queue in memory for any single peer that the specified \fIsocket\fR is communicating with\&. A value of zero means no limit\&.
 | 
						|
.sp
 | 
						|
If this limit has been reached the socket shall enter an exceptional state and depending on the socket type, 0MQ shall take appropriate action such as blocking or dropping sent messages\&. Refer to the individual socket descriptions in \fBzmq_socket\fR(3) for details on the exact action taken for each socket type\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
messages
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
1000
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_SNDTIMEO: Maximum time before a socket operation returns with EAGAIN"
 | 
						|
.sp
 | 
						|
Retrieve the timeout for send operation on the socket\&. If the value is 0, \fIzmq_send(3)\fR will return immediately, with a EAGAIN error if the message cannot be sent\&. If the value is \-1, it will block until the message is sent\&. For all other values, it will try to send the message for that amount of time before returning with an EAGAIN error\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
milliseconds
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1 (infinite)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_TCP_KEEPALIVE: Override SO_KEEPALIVE socket option"
 | 
						|
.sp
 | 
						|
Override \fISO_KEEPALIVE\fR socket option(where supported by OS)\&. The default value of \-1 means to skip any overrides and leave it to OS default\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1,0,1
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1 (leave to OS default)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_TCP_KEEPALIVE_CNT: Override TCP_KEEPCNT socket option"
 | 
						|
.sp
 | 
						|
Override \fITCP_KEEPCNT\fR socket option(where supported by OS)\&. The default value of \-1 means to skip any overrides and leave it to OS default\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1,>0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1 (leave to OS default)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_TCP_KEEPALIVE_IDLE: Override TCP_KEEPCNT(or TCP_KEEPALIVE on some OS)"
 | 
						|
.sp
 | 
						|
Override \fITCP_KEEPCNT\fR(or \fITCP_KEEPALIVE\fR on some OS) socket option (where supported by OS)\&. The default value of \-1 means to skip any overrides and leave it to OS default\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1,>0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1 (leave to OS default)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_TCP_KEEPALIVE_INTVL: Override TCP_KEEPINTVL socket option"
 | 
						|
.sp
 | 
						|
Override \fITCP_KEEPINTVL\fR socket option(where supported by OS)\&. The default value of \-1 means to skip any overrides and leave it to OS default\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1,>0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
\-1 (leave to OS default)
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transports\&.
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_TOS: Retrieve the Type\-of\-Service socket override status"
 | 
						|
.sp
 | 
						|
Retrieve the IP_TOS option for the socket\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
>0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
0
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, only for connection\-oriented transports
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_TYPE: Retrieve socket type"
 | 
						|
.sp
 | 
						|
The \fIZMQ_TYPE\fR option shall retrieve the socket type for the specified \fIsocket\fR\&. The socket type is specified at socket creation time and cannot be modified afterwards\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
int
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SS "ZMQ_ZAP_DOMAIN: Retrieve RFC 27 authentication domain"
 | 
						|
.sp
 | 
						|
The \fIZMQ_ZAP_DOMAIN\fR option shall retrieve the last ZAP domain set for the socket\&. The returned value shall be a NULL\-terminated string and MAY be empty\&. The returned size SHALL include the terminating null byte\&.
 | 
						|
.TS
 | 
						|
tab(:);
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt
 | 
						|
lt lt.
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value type
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
character string
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Option value unit
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
N/A
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Default value
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
not set
 | 
						|
T}
 | 
						|
T{
 | 
						|
.sp
 | 
						|
Applicable socket types
 | 
						|
T}:T{
 | 
						|
.sp
 | 
						|
all, when using TCP transport
 | 
						|
T}
 | 
						|
.TE
 | 
						|
.sp 1
 | 
						|
.SH "RETURN VALUE"
 | 
						|
.sp
 | 
						|
The \fIzmq_getsockopt()\fR function shall return zero if successful\&. Otherwise it shall return \-1 and set \fIerrno\fR to one of the values defined below\&.
 | 
						|
.SH "ERRORS"
 | 
						|
.PP
 | 
						|
\fBEINVAL\fR
 | 
						|
.RS 4
 | 
						|
The requested option
 | 
						|
\fIoption_name\fR
 | 
						|
is unknown, or the requested
 | 
						|
\fIoption_len\fR
 | 
						|
or
 | 
						|
\fIoption_value\fR
 | 
						|
is invalid, or the size of the buffer pointed to by
 | 
						|
\fIoption_value\fR, as specified by
 | 
						|
\fIoption_len\fR, is insufficient for storing the option value\&.
 | 
						|
.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\&.
 | 
						|
.RE
 | 
						|
.SH "EXAMPLE"
 | 
						|
.PP
 | 
						|
\fBRetrieving the high water mark for outgoing messages\fR. 
 | 
						|
.sp
 | 
						|
.if n \{\
 | 
						|
.RS 4
 | 
						|
.\}
 | 
						|
.nf
 | 
						|
/* Retrieve high water mark into sndhwm */
 | 
						|
int sndhwm;
 | 
						|
size_t sndhwm_size = sizeof (sndhwm);
 | 
						|
rc = zmq_getsockopt (socket, ZMQ_SNDHWM, &sndhwm, &sndhwm_size);
 | 
						|
assert (rc == 0);
 | 
						|
.fi
 | 
						|
.if n \{\
 | 
						|
.RE
 | 
						|
.\}
 | 
						|
.sp
 | 
						|
.SH "SEE ALSO"
 | 
						|
.sp
 | 
						|
\fBzmq_setsockopt\fR(3) \fBzmq_socket\fR(3) \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[]\&.
 | 
						|
 |