.\" Copyright (c) 1983, 1991 The Regents of the University of California.
.\" and Copyright (C) 2007, Michael Kerrisk <mtk.manpages@gmail.com>
.\" All rights reserved.
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.\"    notice, this list of conditions and the following disclaimer in the
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.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\"     $Id: listen.2,v 1.4 2001/05/19 02:09:20 hanataka Exp $
.\"
.\" Modified Fri Jul 23 22:07:54 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified 950727 by aeb, following a suggestion by Urs Thuermann
.\" <urs@isnogud.escape.de>
.\" Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 1998 by Andi Kleen
.\" Modified 11 May 2001 by Sam Varshavchik <mrsam@courier-mta.com>
.\"
.\" Japanese Version Copyright (c) 1998 Shinya HANATAKA, Takeshi Hakamada
.\"         all rights reserved.
.\" Translated 1998-04-06,Shinya HANATAKA <shinya@abyss.rim.or.jp>
.\"                   and Takeshi Hakamada <hakamada@nsg.sgi.com>
.\" Modified 2000-01-13, Kentaro Shirakata <argrath@yo.rim.or.jp>
.\" Modified 2001-05-19, Shinya HANATAKA <shinya@abyss.rim.or.jp>
.\" Updated 2007-07-04, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.58
.\" Updated 2008-02-10, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>, LDP v2.77
.\"
.\"WORD:	socket			å
.\"WORD:	listen			ƻ
.\"WORD:	queue			塼
.\"WORD:	descriptor		ǥץ
.\"
.TH LISTEN 2 2007-12-28 "Linux" "Linux Programmer's Manual"
.SH ̾
listen \- å(socket)³Ԥ
.SH 
.nf
.BR "#include <sys/types.h>" "          /* ա׻ */"
.br
.B #include <sys/socket.h>
.sp
.BI "int listen(int " sockfd ", int " backlog );
.fi
.SH 
.BR listen ()

.I sockfd
Ȥ륽åȤ³Ԥå (passive socket) ȤưĤ롣
³ԤåȤȤϡ
.BR accept (2)
Ȥä夷³׵դΤ˻Ѥ륽åȤǤ롣

.I sockfd
ϡ
.B SOCK_STREAM

.B SOCK_SEQPACKET
ΥåȤ򻲾ȤեǥץǤ롣

.I backlog
ϡ
.I sockfd
ˤĤƤα³Υ塼κĹꤹ롣
塼äѤξ֤³׵᤬夹ȡ饤Ȥ
.B ECONNREFUSED
Ȥ顼롣ؤΥץȥ뤬򥵥ݡ
ƤС׵̵뤵졢ʹߤ³׵κ뤫⤷ʤ
.SH ֤
ˤ0֤顼ˤ \-1֤
.I errno
Ŭڤꤹ롣
.SH 顼
.TP
.B EADDRINUSE
̤ΥåȤƱݡȤ listen Ƥ롣
.TP
.B EBADF

.I sockfd
ͭʥǥץǤϤʤ
.TP
.B ENOTSOCK

.I sockfd
ϥåȤǤϤʤ
.TP
.B EOPNOTSUPP
åȤ
.BR listen ()
ݡȤƤ뷿ǤϤʤ
.SH 
4.4BSD, POSIX.1-2001.
.BR listen ()
ؿ 4.2BSDǽƼ줿
.SH 
³դˤϡʲν¹Ԥ롣
.RS 4
.IP 1. 4
.BR socket (2)
ǥåȤ롣
.IP 2.
.BR bind (2)
ȤäƥåȤ˥륢ɥ쥹Ƥơ
¾ΥåȤΥåȤ
.BR connect (2)
Ǥ褦ˤ롣
.IP 3.
.BR listen ()
Ȥäơ³׵դջ֤³׵륭塼Ĺꤹ롣
.IP 4.
.BR accept (2)
Ȥä³դ롣
.RE
.PP
POSIX.1-2001 Ǥ
.I <sys/types.h>
Υ󥯥롼ɤɬܤȤƤ餺
Linux ǤϤΥإåեɬפǤϤʤ
ŪˤϡĤμ (BSD ) ǤΥإåե뤬
ɬפǤꡢܿɬפʥץꥱǤϤΥե
󥯥롼ɤΤǤ

TCP åȤǤ
.I backlog
ο񤤤 Linux 2.2 ѹ줿
ߤǤϤΰϡ
դΤԤäƤ롢
.I 
Ω줿åȤΥ塼Ĺꤹ롣
Դ³׵οǤä֤
ԴʥåȤΥ塼κĹ
sysctl ؿ
.I tcp_max_syn_backlog
ѤƥåȤ롣
syncookie ͭˤʤäƤ硢
Ū˺Ÿߤ
sysctl ؿˤ̵뤵롣

.I backlog

.I /proc/sys/net/core/somaxconn
ͤ礭С
.I backlog
ͤϰۤΤˤͤڤͤ롣
ΥեΥǥեͤ 128 Ǥ롣
С 2.4.5 ΥͥǤϡξͤ
ߤθ
.B SOMAXCONN
Ǥꡢͤ 128 Ǥä
.\" ʲϡǤϸŤǤ롣(MTK, Jun 05)
.\" BSD (ȡĤ BSD ƥ)Ǥ backlog  5 
.\" ¤ƤΤǡܿθץꥱǤ
.\"  (SOMAXCONN) äƤϤʤ
.SH 
.BR bind (2)
ȡ
.SH Ϣ
.BR accept (2),
.BR bind (2),
.BR connect (2),
.BR socket (2)