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Copyright 1989 AT&T
Copyright (C) 1999, Sun Microsystems,
Inc. All Rights Reserved
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
LISTEN 3SOCKET "Nov 8, 1999"
NAME
listen - listen for connections on a socket
SYNOPSIS

cc [ flag ... ] file ... -lsocket  -lnsl  [ library ... ]
#include <sys/types.h>
#include <sys/socket.h>

int listen(int s, int backlog);
DESCRIPTION

To accept connections, a socket is first created with socket(3SOCKET), a backlog for incoming connections is specified with listen() and then the connections are accepted with accept(3SOCKET). The listen() call applies only to sockets of type SOCK_STREAM or SOCK_SEQPACKET.

The backlog parameter defines the maximum length the queue of pending connections may grow to.

If a connection request arrives with the queue full, the client will receive an error with an indication of ECONNREFUSED for AF_UNIX sockets. If the underlying protocol supports retransmission, the connection request may be ignored so that retries may succeed. For AF_INET and AF_INET6sockets, the TCP will retry the connection. If the backlog is not cleared by the time the tcp times out, the connect will fail with ETIMEDOUT.

RETURN VALUES

A 0 return value indicates success; -1 indicates an error.

ERRORS

The call fails if: EBADF

The argument s is not a valid file descriptor.

ENOTSOCK

The argument s is not a socket.

EOPNOTSUPP

The socket is not of a type that supports the operation listen().

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
MT-Level Safe
SEE ALSO

accept(3SOCKET), connect(3SOCKET), socket(3SOCKET), attributes(5), socket.h(3HEAD)

NOTES

There is currently no backlog limit.