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REALHOSTNAME(3)		 BSD Library Functions Manual	       REALHOSTNAME(3)

NAME
     realhostname -- convert an	IP number to the real host name

LIBRARY
     System Utilities Library (libutil,	-lutil)

SYNOPSIS
     #include <libutil.h>

     int
     realhostname(char *host, size_t hsize, const struct in_addr *ip);

DESCRIPTION
     The function realhostname() converts ip to	the corresponding host name.
     This is done by resolving ip to a host name and then ensuring that	the
     host name resolves	back to	ip.

     host must point to	a buffer of at least hsize bytes, and will always be
     written to	by this	function.

     If	the name resolution does not work both ways or if the host name	is
     longer than hsize bytes, inet_ntoa(3) is used to convert ip to an ASCII
     form.

     If	the string written to host is hsize bytes long,	host will not be NUL
     terminated.

RETURN VALUES
     The realhostname()	function will return one of the	following constants
     which are defined in <libutil.h>:

	HOSTNAME_FOUND
	     A valid host name was found.

	HOSTNAME_INCORRECTNAME
	     A host name was found, but	it did not resolve back	to the passed
	     ip.  host now contains the	numeric	value of ip.

	HOSTNAME_INVALIDADDR
	     ip	could not be resolved.	host now contains the numeric value of
	     ip.

	HOSTNAME_INVALIDNAME
	     A host name was found, but	it could not be	resolved back to any
	     ip	number.	 host now contains the numeric value of	ip.

SEE ALSO
     gethostbyaddr(3), gethostbyname(3), inet_ntoa(3), realhostname_sa(3)

BSD				 April 6, 1999				   BSD

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO

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