.\" Copyright 2000 Sam Varshavchik <mrsam@courier-mta.com>
.\"
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.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
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.\" manual under the conditions for verbatim copying, provided that the
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.\" 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.\" manual page may be incorrect or out-of-date.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
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.\" Formatted or processed versions of this manual, if unaccompanied by
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.\" References: RFC 2553
.\"
.\" Japanese Version Copyright (c) 2001 NAKANO Takeo all rights reserved.
.\" Translated Sun Jan 14 2001 by NAKANO Takeo <nakano@apm.seikei.ac.jp>
.\"
.\"WORD:	null pointer	̥롦ݥ󥿡
.\"
.TH getaddrinfo 3 "Dec 18, 2000" "Linux Man Page" "Linux Programmer's Manual"
.SH ̾
getaddrinfo \- ͥ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
.B 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
.I ai_next
Сǥ󥯤줿
.B addrinfo
¤ΤΥ󥯥ꥹȤưŪƤˤäƺ
.I res
ˤƬؤΥݥ󥿤ꤹ롣
ʣ
.B addrinfo
¤Τʤ󥯥ꥹȤѤ뤳ȤˤΤˤͳ롣
㤨СͥåȥۥȤޥۡξ䡢
ʣΥåȥץȥƱӥȤ
(ҤȤĤ
.B SOCK_STREM
ɥ쥹ǡ⤦ҤȤĤ
.B SOCK_DGRAM
ɥ쥹Ǥʤ) Թ礬Ǥ롣
.PP
.IR ai_family ,
.IR ai_socktype ,
.I ai_protocol
Сϡ줾
.BR socket (2)
ƥॳбƱ̣ġ
.BR getaddrinfo (3)
ؿ IPv4 뤤 IPv6 ɥ쥹եߥ꡼Υåȥɥ쥹֤
.RI ( ai_family

.B PF_INET
ޤ
.B PF_INET6
Τ줫˥åȤ)
.PP
.I hints
ѥ᡼ˤϡͥ褵åȤΥ (뤤ϥץȥ)
ꤹ롣
.I hints
 NULL
ˤ뤳ȤϡƤΥͥåȥɥ쥹/ץȥ뤬
ǽǤ뤳Ȥ̣롣
Υѥ᡼
.B NULL
ǤʤȤϡ
.B addrinfo
¤ΤݥȤ褦ˤ롣
ι¤Τ
.IR ai_familiy ,
.IR ai_socktype ,
.I ai_protocol
Сǡͥ褵륽åȥפʤɤꤹ롣
.I ai_family

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

.I ai_protocol
 0 ꤹȡ
ƱͤǤդΥåȥפץȥդ뤳Ȥ̣롣
.I ai_flags
Сˤɲåץꤹ (ϰʲ)
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 (ξƱˤԲ)
.I node
ˤϿͷΥͥåȥɥ쥹
(IPv4 ʤɥåȶڤ 10 ʷ
IPv6 ʤ 16 ʷ) 뤤ϥͥåȥۥȤ̾ꤹ롣
Ԥξϡ̾ƥͥåȥɥ쥹β褬Ǥɬפ롣
.I hints
ѥ᡼
.I ai_flags
С
.B AI_NUMERICHOST
ե饰ޤޤƤϡ
.I node
ѥ᡼ϿŪʥͥåȥɥ쥹ǤʤФʤʤ
.B AI_NUMERICHOST
ե饰ȤС
ۥȤ̾ɥ쥹Ĺ֤äƤޤǽӽǤ롣
.PP
.BR getaddrinfo (3)
ؿ
.B addrinfo
¤ΤΥ󥯥ꥹȤ뤬
Ǥγƥͥåȥɥ쥹
.I hints
ѥ᡼ˤä줿¤˽Ȥˤʤ롣
.I hints

.B AI_CANONNAME
ե饰ޤޤƤˤϡ
.I ai_cannonname
ϥۥȤΥե̾ݥȤ褦ꤵ롣
.IR ai_family ,
.IR ai_socktype ,
.I ai_protocol
ƥСϥåΥѥ᡼ꤹ롣
.I ai_addr
Сˤϥåȥɥ쥹ؤΥݥ󥿤񤭹ޤ졢
.I ai_addrlen
Сˤϥåȥɥ쥹Ĺ (Хñ) 񤭹ޤ롣
.PP
.I node
 NULL ξϡƥåȹ¤ΤΥͥåȥɥ쥹ν
.B AI_PASSIVE
ե饰˴Ťƽ
(Υե饰
.I hints
ѥ᡼
.I ai_flags
Сꤵ)
.B AI_PASSIVE
ե饰åȤƤ顢
ƥåȹ¤ΤΥͥåȥɥ쥹ϻꤵʤޤޤˤʤ롣
ǤդΥͥåȥɥ쥹Υ饤³Ԥ褦
СץꥱѤ롣
.B AI_PASSIVE
ե饰åȤƤʤȡ
ͥåȥɥ쥹 loopback 󥿡եɥ쥹ꤵ롣
ϸߤΥۥȾưƤ륵С³뤳ȤտޤƤ
饤ȥץꥱѤ롣
.PP
.I service
ϡƥåȹ¤ΤΥͥåȥɥ쥹Υݡֹꤹ롣
.I service
 NULL ʤݡֹʤޤޤˤ롣
.PP
.BR freeaddrinfo (3)
ؿϡ
.I res
ݥȤ󥯥ꥹȤưŪ˳Ƥ줿롣
.SH ֤
.BR getaddrinfo (3)
 0 ֤ԤȰʲ 0 Υ顼ɤΤ줫֤
.TP
.B EAI_FAMILY
׵ᤵ줿ɥ쥹եߥ꡼ݡȤƤʤ
.TP
.B EAI_SOCKTYPE
׵ᤵ줿åȥפݡȤƤʤ
.TP
.B EAI_BADFLAGS
.I ai_flags
Υե饰
.TP
.B EAI_NONAME
.I node
뤤
.I service
Τ줫狼ʤ
.I node

.I service
ξ NULL ä⤳Υ顼֤롣
.TP
.B EAI_SERVICE
׵ᤵ줿ӥϡ׵ᤵ줿åȥפǤѤǤʤ
¾ΥåȥפǤʤѲǽ⤷ʤ
.TP
.B EAI_ADDRFAMILY
ꤵ줿ͥåȥۥȤϡ
׵ᤵ줿ɥ쥹եߥ꡼бͥåȥɥ쥹äƤʤ
.TP
.B EAI_NODATA
ꤵ줿ͥåȥۥȤ¸ߤ뤬
ͥåȥɥ쥹Ƥʤ
.TP
.B EAI_MEMORY
꤬­ʤ
.TP
.B EAI_FAIL
͡ॵС鹱Ūʼ (permanent failure)
ֻ̣֤줿
.TP
.B EAI_AGAIN
͡ॵСŪʼ (temporary failure)
ֻ̣֤줿Ǥ⤦ٻƤߤ衣
.TP
.B EAI_SYSTEM
¾Υƥ२顼ܤ
.I errno
Ĵ٤뤳ȡ
.PP
.BR gai_strerror (3)
ؿѤȡΥ顼ɤʹ֤˲ɤʸѴǤΤǡ
顼Ŭ
.SH Ϣ
.BR getipnodebyname (3),
.BR getipnodebyaddr (3)