.\" This page is in the public domain.
.\" Almost all details are from RFC 2553.
.\"
.TH getnameinfo 3 "11 December 2000" "Linux Man Page" "UNIX Programmer's Manual"
.SH ̾
getnameinfo \- ɥ쥹̾ؤѴץȥ˰¸ʤǹԤ
.SH 
.nf
.B #include <sys/socket.h>
.B #include <netdb.h>
.sp
.BI "int getnameinfo(const struct sockaddr *" "sa" ", socklen_t " "salen" ,
.BI "                char *" "host" ", size_t " "hostlen" ,
.BI "                char *" "serv" ", size_t " "servlen" ", int " "flags" );
.fi
.SH 
.BR getnameinfo(3)
ؿϡɥ쥹Ρ̾ؤѴ
ץȥ˰¸ʤǹԤ˵ꤵ줿
δؿ
.BR gethostbyaddr (3)

.BR getservbyport (3)
εǽ򤤤äˤΤǡ
.BR getaddrinfo (3)
ȵդưԤ
.I sa
ϡ
IP ɥ쥹ȥݡֹξݻƤ
ͥåʥåȥɥ쥹¤
.RI ( sockaddr_in
ޤ
.I sockaddr_in6
) ؤΥݥ󥿡Ǥ롣
.I salen

.I sa
ΥǤ롣
.I host

.I serv
ϡ(줾쥵
.I hostlen

.I servlen
) ХåեؤΥݥ󥿡Ǥꡢ
֤ͤ롣
.PP
.I host
(ޤ
.IR serv )
 NULL ꤹ뤫뤤
.I hostlen
(ޤ
.IR servlen )
 0 ꤹС
ۥ̾ (ޤϥӥ̾) פǤ뤳Ȥ뤳ȤǤ롣
ۥ̾ޤϥӥ̾
ʤȤ⤤줫ҤȤĤϥꥯȤʤФʤʤ
.PP
.I flags

.BR getnameinfo (3)
ư롣Ǥͤϰʲ̤:
.TP
.B NI_NOFQDN
ꤹȡʥۥȤˤ FQDN Υۥ̾ʬΤߤ֤
.TP
.B NI_NUMERICHOST
.\" For example, by calling
.\" .I inet_ntop()
.\" instead of
.\" .IR gethostbyaddr() .
ꤹȡۥ̾οɽ֤롣
㤨
.I gethostbyaddr()

.I inet_ntop()
Ƥ (ꤷʤƤ⡢
Ρɤ̾ʤϤΤ褦ˤʤ뤳ȤϤ)
.TP
.B NI_NAMEREQD
ꤹȡۥ̾ʤä˥顼֤
.TP
.B NI_NUMERICSERV
ꤹȡӥ̾ɽ (㤨Хݡֹ) ֤롣
.TP
.B NI_DGRAM
ꤹȡȥ꡼١ (TCP) Ǥʤǡ١ (UDP)
Υӥоݤˤ롣Ͼʤ
UDP  TCP ǰ㤦ӥ󶡤Ƥݡ
(512-514) ФɬפȤʤ롣
.SH ֤
 0 ֤ꡢ(׵ᤵƤ) Ρɤȥӥ̾
̥ʸǽü줿ʸηǤ줾λХåե֤
(ХåեĹˤ褦˽̤뤫⤷ʤ)
顼 0 ʳ֤ͤ졢
.I errno
бͤꤵ롣
.SH 顼
.TP
.B EAI_AGAIN
ꤵ줿̾ǤϲǤʤä
Ǥ⤦ٻƤߤ衣
.TP
.B EAI_BADFLAGS
.I flags
ͤͿ줿
.TP
.B EAI_FAIL
Ǥʤ顼ȯ
.TP
.B EAI_FAMILY
ꤷɥ쥹եߥ꡼ǧǤʤä
뤤ϥɥ쥹Ĺꤵ줿եߥ꡼˹礦ΤǤʤä
.TP
.B EAI_MEMORY
꤬­ʤ
.TP
.B EAI_NONAME
Ϳ줿ѥ᡼Ǥ̾Ǥʤ
NI_NAMEREQD ꤵƤۥ̾Ǥʤä
ۥ̾⥵ӥ̾׵ᤵʤä
.TP
.B EAI_SYSTEM
ƥ२顼ä
顼ɤ
.I errno
ꤵ롣
.SH ե
/etc/hosts
.br
/etc/nsswitch.conf
.br
/etc/resolv.conf
.SH 
ͿХåեŬڤʥǤ褦
.I <netdb.h>
ˤϰʲƤ롣
.sp
.RS
.nf
# define NI_MAXHOST      1025
.br
# define NI_MAXSERV      32
.fi
.RE
.sp
ԤϺǶǤ BIND Υإåե
.I <arpa/nameser.h>
 MAXDNAME Ǥ롣Ԥϸߤγƿͤ RFC
˥ꥹȤƤ륵ӥ̤ͤǤ롣
.SH 
ʲΥɤͿåȥɥ쥹Ф
ۥȤȥӥοɽ褦Ȼߤ롣
Υɥ쥹եߥ꡼Ф뻲Ⱦ
ڥϡɥɤƤʤȤܤƤۤ
.sp
.RS
.nf
  struct sockaddr *sa;    /* input */
  char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];

  if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), sbuf,
      sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0)
          printf("host=%s, serv=%s\en", hbuf, sbuf);
.fi
.RE
.sp
ʲǤϥåȥɥ쥹
ոΥɥ쥹ޥåԥ󥰤¸ߤ뤫åƤ롣
.sp
.RS
.fi
  struct sockaddr *sa;    /* input */
  char hbuf[NI_MAXHOST];

  if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf),
      NULL, 0, NI_NAMEREQD))
         printf("could not resolve hostname");
  else
         printf("host=%s\en", hbuf);
.fi
.RE
.SH 
RFC 2553. (See also XNS, issue 5.2.)
.SH Ϣ
.BR getaddrinfo (3),
.BR gethostbyaddr (3),
.BR getservbyname (3),
.BR getservbyport (3),
.BR inet_ntop (3),
.BR socket (3),
.BR hosts (5),
.BR services (5),
.BR hostname (7),
.BR named (8)
.LP
R. Gilligan, S. Thomson, J. Bound and W. Stevens,
.IR "Basic Socket Interface Extensions for IPv6" ,
RFC 2553, March 1999.
.LP
Tatsuya Jinmei and Atsushi Onoe,
.IR "An Extension of Format for IPv6 Scoped Addresses" ,
internet draft, work in progress.
ftp://ftp.ietf.org/internet-drafts/draft-ietf-ipngwg-scopedaddr-format-02.txt
.LP
Craig Metz,
.IR "Protocol Independence Using the Sockets API" ,
Proceedings of the freenix track:
2000 USENIX annual technical conference, June 2000.
http://www.usenix.org/publications/library/proceedings/usenix2000/freenix/metzprotocol.html