.\" Copyright 2000 Sam Varshavchik <mrsam@courier-mta.com>
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" References: RFC 2553
.\"
.\" 2005-08-09, mtk, added AI_ALL, AI_ADDRCONFIG, AI_V4MAPPED, 
.\"			and AI_NUMERICSERV.
.\"
.\" Japanese Version Copyright (c) 2001 NAKANO Takeo all rights reserved.
.\" Translated Sun Jan 14 2001 by NAKANO Takeo <nakano@apm.seikei.ac.jp>
.\" Updated Oct  9 2005 by Kentaro Shirakata <argrath@ub32.org>
.\"
.\"WORD:	null pointer	̥롦ݥ
.\"
.TH getaddrinfo 3 2000-12-18 "Linux Man Page" "Linux Programmer's Manual"
.SH ̾
getaddrinfo, freeaddrinfo, gai_strerror \- ͥåȥΥɥ쥹ȥӥѴ
.SH 
.nf
.B #include <sys/types.h>
.B #include <sys/socket.h>
.B #include <netdb.h>
.sp
.BI "int getaddrinfo(const char *" "node" ", const char *" "service" ,
.BI "                const struct addrinfo *" "hints" ,
.BI "                struct addrinfo **" "res" );
.sp
.BI "void freeaddrinfo(struct addrinfo *" "res" );
.sp
.BI "const char *gai_strerror(int " "errcode" );
.fi
.SH 
.BR getaddrinfo (3)
ؿϡ4 Ĥδؿ
.BR getipnodebyname (3),
.BR getipnodebyaddr (3),
.BR getservbyname (3),
.BR getservbyport (3)
εǽޤȤưĤΥ󥿡եˤΤǤ롣
.BR getaddrinfo (3)
ؿϥåɥդǡ
ҤȤİʾΥåȥɥ쥹¤Τ롣
ι¤Τ
.BR bind (2)

.BR connect (2)
ʤɤδؿǥ饤ѡСѤΥåȤݤ
Ѥ뤳ȤǤ롣
.PP
.BR getaddrinfo (3)
ؿ뤳ȤΤǤΤ IPv4 ɥ쥹¤ΤǤϤʤ
IPv6 ΥݡȤƤ륷ƥʤ
IPv6 Υåȥɥ쥹¤ΤǤ롣
Υåȥɥ쥹¤Τϡ
饤Ȥ䥵СǥåȤݤˡ
.BR bind (2)

.BR connect (2)
ľѤǤ롣
.PP
δؿѤ
.I addrinfo
¤ΤˤϰʲΥСޤޤƤ롣
.sp
.nf
.B struct addrinfo {
.BI "    int     " "ai_flags" ";"
.BI "    int     " "ai_family" ";"
.BI "    int     " "ai_socktype" ";"
.BI "    int     " "ai_protocol" ";"
.BI "    size_t  " "ai_addrlen" ";"
.BI "    struct sockaddr *" "ai_addr" ";"
.BI "    char   *" "ai_canonname" ";"
.BI "    struct addrinfo *" "ai_next" ";"
.B };
.fi
.PP
.BR getaddrinfo (3)
ϡ
ưŪ˳Ƥ
.I addrinfo
¤ΤΥ󥯥ꥹȤ
Υ󥯥ꥹȤؤΥݥ󥿤
.I res
ꤹ롣
ƹ¤Τ
.I ai_next
Сǥ󥯤롣
󥯥ꥹȤ
.I addrinfo
¤ΤʣĤˤʤ뤳Ȥ⤢ꡢͳϤĤ롣
ͥåȥۥȤޥۡξ硢
ʣΥåȥץȥƱӥȤ
(ҤȤĤ
.B SOCK_STREM
ɥ쥹ǡ⤦ҤȤĤ
.B SOCK_DGRAM
ɥ쥹Ǥʤ) 硢롣
.PP
.IR ai_family ,
.IR ai_socktype ,
.I ai_protocol
Сϡ줾
.BR socket (2)
ƥॳбƱ̣ġ
.BR getaddrinfo (3)
ؿ IPv4  IPv6 Τɤ餫Υɥ쥹եߥ꡼Υåȥɥ쥹֤
.RI ( ai_family

.B AF_INET
ޤ
.B AF_INET6
Τɤ餫˥åȤ)
.PP
.I hints
ѥ᡼ˤϡ˾ΥåȤΥפץȥ
ꤹ롣
.I hints
 NULL
ˤ뤳Ȥϡɤʥͥåȥɥ쥹ץȥǤ褤Ȥ̣롣
Υѥ᡼ NULL ǤʤȤϡ
.I addrinfo
¤ΤؤΥݥ󥿤Ȥʤ롣
ι¤Τ
.IR ai_familiy ,
.IR ai_socktype ,
.I ai_protocol
Сǡ˾Υåȥפʤɤꤹ롣
.I ai_family

.B AF_UNSPEC
ꤹȡǤդΥץȥեߥ꡼̣ (㤨 IPv4  IPv6)
.I ai_socktype

.I ai_protocol
 0 ꤹȡ
ƱͤǤդΥåȥפץȥդ뤳Ȥ̣롣
.I ai_flags
Сˤɲåץꤹ (ϲΤȤ)
ʣΥե饰ꤹˤϡ OR ȤäƻꤹФ褤
.I hints
ѥ᡼Τ¾ΥСˤϡ
0 (ޤϥ̥롦ݥ) ʤФʤʤ
.PP
.I node
ѥ᡼
.I service
ѥ᡼Τɤ餫 NULL ˤƤ褤 (ξƱ NULL Բ)
.I node
ˤϿͷΥͥåȥɥ쥹
(IPv4 ʤɥåȶڤ 10 ʷ
IPv6 ʤ 16 ʷ) 뤤ϥͥåȥۥ̾ꤹ롣
Ԥξϡͥåȥɥ쥹졢̾褬Ԥʤ롣
.I hints.ai_flags

.B AI_NUMERICHOST
ե饰ޤޤƤϡ
.I node
ѥ᡼ϿŪʥͥåȥɥ쥹ǤʤФʤʤ
.B AI_NUMERICHOST
ե饰Ȥȡ
֤γݤǽΤ뤹٤ƤΥͥåȥۥȥɥ쥹θ롣
.PP
.BR getaddrinfo (3)
ؿ
.I addrinfo
¤ΤΥ󥯥ꥹȤ뤬
줾Υͥåȥɥ쥹
.I hints
ѥ᡼Dzݤ줿٤Ƥ¤˽äƤ롣
.I hints.ai_flags

.B AI_CANONNAME
ե饰ޤޤƤ硢
.I addrinfo 
¤Τκǽ
.I ai_canonname
եɤˤϥۥȤθ̾ؤ褦ꤵ롣
.IR ai_family ,
.IR ai_socktype ,
.I ai_protocol
ƥСˤϥåΥѥ᡼ꤵ롣
.I ai_addr
Сˤϥåȥɥ쥹ؤΥݥ󥿤񤭹ޤ졢
.I ai_addrlen
Сˤϥåȥɥ쥹Ĺ (Хñ) 񤭹ޤ롣
.PP
.I node
 NULL ξ硢ƥåȹ¤ΤΥͥåȥɥ쥹
.B AI_PASSIVE
ե饰˴Ťƽ
(Υե饰
.I hints.ai_flags
ꤵ)
.B AI_PASSIVE
ե饰åȤƤ硢
ƥåȹ¤ΤΥͥåȥɥ쥹ꤵʤޤޤȤʤ
(: IPv4 ξ INADDR_ANY ˡIPv6 ξ IN6ADDR_ANY_INIT )
Ϥ٤ƤΥͥåȥɥ쥹ǥ饤³Ԥ褦
СץꥱѤ롣
.B AI_PASSIVE
ե饰åȤƤʤ硢
ͥåȥɥ쥹 loopback 󥿡եɥ쥹ꤵ롣
ƱͥåȥۥȾưƤ륵С³褦
饤ȥץꥱѤ롣
.PP
.I hints.ai_flags

.B AI_ADDRCONFIG
ޤ硢
.I result
ؤꥹȤˤϡ
륷ƥ˺Ĥ IPv4 ɥ쥹ꤵƤ
IPv4 ɥ쥹֤졢
륷ƥ˺Ĥ IPv6 ɥ쥹ꤵƤ
IPv6 ɥ쥹֤롣
.PP
.I hint.ai_flags

.B AI_V4MAPPED
ꤵƤơ
.I hints.ai_family

.B AF_INET6
ꤵ졢
ޥå IPv6 ɥ쥹Ĥʤä硢
.I result
ؤꥹȤˤ IPv4-mapped IPv6 ɥ쥹֤롣
.I hints.ai_family

.B AI_V4MAPPED

.B AI_ALL
ξꤵƤ硢
.I result
ؤꥹȤˤ IPV6 ɥ쥹 IPv4-mapped IPv6 ɥ쥹
ξ֤롣
.B AI_V4MAPPED
ꤵƤʤ硢
.B AI_ALL
̵뤵롣
.PP
.I service
ϡƥåȹ¤ΤΥͥåȥɥ쥹Υݡֹꤹ롣
.I service
 NULL ξ硢ݡֹϽʤ
.I hints.ai_flags 

.B AI_NUMERICSERV
ꤵ졢
.I service
 NULL Ǥʤ硢
.I service
ϿͤΥݡֹޤʸؤʤФʤʤ
Υե饰ϡ̾襵ӥפǤ뤳ȤʬäƤˡ
ӥεư뤿Ѥ롣
.PP
.BR freeaddrinfo (3)
ؿϡ
󥯥ꥹ
.I res
ФưŪ˳Ƥ줿롣
.SH ֤
.BR getaddrinfo (3)
 0 ֤ԤȰʲ 0 Υ顼ɤΤ줫֤
.TP
.B EAI_ADDRFAMILY
ꤵ줿ͥåȥۥȤˤϡ
׵ᤵ줿ɥ쥹եߥ꡼Υͥåȥɥ쥹ʤ
.TP
.B EAI_AGAIN
͡ॵСŪʼ (temporary failure)
ֻ̣֤줿Ǥ⤦ٻƤߤ衣
.TP
.B EAI_BADFLAGS
.I ai_flags
Υե饰ʥե饰ޤޤƤ롣
.TP
.B EAI_FAIL
͡ॵС鹱Ūʼ (permanent failure)
ֻ̣֤줿
.TP
.B EAI_FAMILY
׵ᤵ줿ɥ쥹եߥ꡼ݡȤƤʤ
.TP
.B EAI_MEMORY
꤬­ʤ
.TP
.B EAI_NODATA
ꤵ줿ͥåȥۥȤ¸ߤ뤬
ͥåȥɥ쥹ҤȤĤƤʤ
.TP
.B EAI_NONAME
.I node

.I service
Τɤ餫ޤ
.I node

.I service
ξ NULL ä硢ޤ
.B AI_NUMERICSERV

.I hints.ai_flags
˻ꤵƤơ
.I hints.ai_flags

.I service
ͤΥݡֹʸǤʤ
.TP
.B EAI_SERVICE
׵ᤵ줿ӥϡ׵ᤵ줿åȥפǤѤǤʤ
¾ΥåȥפǤʤѲǽ⤷ʤ
.TP
.B EAI_SOCKTYPE
׵ᤵ줿åȥפݡȤƤʤ
.TP
.B EAI_SYSTEM
¾Υƥ२顼ܤ
.I errno
Ĵ٤뤳ȡ
.PP
.BR gai_strerror (3)
ؿѤȡΥ顼ɤʹ֤˲ɤʸѴǤΤǡ
顼Ŭ
.SH 
POSIX.1-2001.
.BR getaddrinfo ()
ؿ RFC 2553 ˵ܤƤ롣
.SH 
.BR AI_ADDRCONFIG ,
.BR AI_ALL ,
.B AI_V4MAPPED
 glibc 2.3.3 ʹߤѲǽǤ롣
.B AI_NUMERICSERV
 glibc 2.3.4 ʹߤѲǽǤ롣
.SH Ϣ
.BR getipnodebyaddr (3),
.BR getipnodebyname (3)