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REALHOSTNAME_SA(3)     FreeBSD Library Functions Manual	    REALHOSTNAME_SA(3)

NAME
     realhostname_sa --	convert	a struct sockaddr to the real host name

LIBRARY
     System Utilities Library (libutil,	-lutil)

SYNOPSIS
     #include <sys/types.h>
     #include <netinet/in.h>
     #include <libutil.h>

     int
     realhostname_sa(char *host, size_t	hsize, struct sockaddr *addr,
	 int addrlen);

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

     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, getnameinfo(3) with NI_NUMERICHOST specified, is
     used to convert addr to an	ASCII form.

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

RETURN VALUES
     The realhostname_sa() 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
     getaddrinfo(3), getnameinfo(3), realhostname(3)

FreeBSD	Ports 11.2	       January 11, 2000		    FreeBSD Ports 11.2

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

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