GETIPNODEBYNAME(3)	   Linux Programmers Manual	   GETIPNODEBYNAME(3)



NAME
       getipnodebyname,  getipnodebyaddr,  freehostent - get network hostnames
       and addresses

SYNOPSIS
       #include 
       #include 
       #include 

       struct hostent *getipnodebyname(const char *name, int af,
				       int flags, int *error_num);

       struct hostent *getipnodebyaddr(const void *addr, size_t len,
				       int af, int *error_num);

       void freehostent(struct hostent *ip);

DESCRIPTION
       These functions are deprecated (and unavailable in glibc).  Use	getad
       drinfo(3) and getnameinfo(3) instead.

       The  getipnodebyname() and getipnodebyaddr() functions return the names
       and addresses of a network host.  These functions return a  pointer  to
       the following structure:

	   struct  hostent {
	       char  *h_name;
	       char **h_aliases;
	       int    h_addrtype;
	       int    h_length;
	       char **h_addr_list;
	   };

       These functions replace the gethostbyname(3) and gethostbyaddr(3) func
       tions, which could only access the IPv4 network	address  family.   The
       getipnodebyname()  and  getipnodebyaddr() functions can access multiple
       network address families.

       Unlike the gethostby functions,	these  functions  return  pointers  to
       dynamically  allocated  memory.	 The freehostent() function is used to
       release the dynamically allocated memory after  the  caller  no	longer
       needs the hostent structure.

   getipnodebyname() arguments
       The  getipnodebyname() function looks up network addresses for the host
       specified by the name argument.	The af argument specifies one  of  the
       following values:

       AF_INET
	      The name argument points to a dotted-quad IPv4 address or a name
	      of an IPv4 network host.

       AF_INET6
	      The name argument points to a hexadecimal IPv6 address or a name
	      of an IPv6 network host.

       The  flags argument specifies additional options.  More than one option
       can be specified by logically OR-ing them together.   flags  should  be
       set to 0 if no options are desired.

       AI_V4MAPPED
	      This  flag  is  used  with  AF_INET6 to request a query for IPv4
	      addresses instead of IPv6 addresses; the IPv4 addresses will  be
	      mapped to IPv6 addresses.

       AI_ALL This  flag  is used with AI_V4MAPPED to request a query for both
	      IPv4 and IPv6 addresses.	Any IPv4 address found will be	mapped
	      to an IPv6 address.

       AI_ADDRCONFIG
	      This  flag is used with AF_INET6 to further request that queries
	      for IPv6 addresses should not be made unless the system  has  at
	      least one IPv6 address assigned to a network interface, and that
	      queries for IPv4 addresses should not be made unless the	system
	      has  at  least one IPv4 address assigned to a network interface.
	      This flag may be used by itself or with the AI_V4MAPPED flag.

       AI_DEFAULT
	      This flag is equivalent to (AI_ADDRCONFIG | AI_V4MAPPED).

   getipnodebyaddr() arguments
       The getipnodebyaddr() function looks up the name of the host whose net
       work address is specified by the addr argument.	The af argument speci
       fies one of the following values:

       AF_INET
	      The addr argument points to a struct in_addr and len must be set
	      to sizeof(struct in_addr).

       AF_INET6
	      The  addr  argument  points to a struct in6_addr and len must be
	      set to sizeof(struct in6_addr).

RETURN VALUE
       A null pointer is returned if an error  occurred,  and  error_num  will
       contain an error code from the following list:

       HOST_NOT_FOUND
	      The hostname or network address was not found.

       NO_ADDRESS
	      The  domain  name server recognized the network address or name,
	      but no answer was returned.  This can happen if the network host
	      has  only  IPv4  addresses  and a request has been made for IPv6
	      information only, or vice versa.

       NO_RECOVERY
	      The domain name server returned a permanent failure response.

       TRY_AGAIN
	      The domain name server returned a  temporary  failure  response.
	      You might have better luck next time.

       A  successful  query returns a pointer to a hostent structure that con
       tains the following fields:

       h_name This is the official name of this network host.

       h_aliases
	      This is an array of pointers to unofficial aliases for the  same
	      host.  The array is terminated by a null pointer.

       h_addrtype
	      This  is	a  copy  of  the  af  argument to getipnodebyname() or
	      getipnodebyaddr().  h_addrtype will always be AF_INET if the  af
	      argument was AF_INET.  h_addrtype will always be AF_INET6 if the
	      af argument was AF_INET6.

       h_length
	      This field will be set to sizeof(struct in_addr)	if  h_addrtype
	      is  AF_INET,  and  to  sizeof(struct  in6_addr) if h_addrtype is
	      AF_INET6.

       h_addr_list
	      This is an array of one or  more	pointers  to  network  address
	      structures  for  the network host.  The array is terminated by a
	      null pointer.

CONFORMING TO
       RFC 2553.

NOTES
       These functions were present  in  glibc	2.1.91-95,  but  were  removed
       again.	Several Unix-like systems support them, but all call them dep
       recated.

SEE ALSO
       getaddrinfo(3), getnameinfo(3), inet_ntop(3), inet_pton(3)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2007-11-15		    GETIPNODEBYNAME(3)