Synopsis:
   $iptoname(<ip address>)
   $nametoip(<hostname>)

Technical:
   These functions are used to convert an IP address to a hostname, and vice
   versa.   The $iptoname() function returns the hostname associated with
   the given IP address, and $nametoip() does the opposite.

Practical:
   These functions are used to convert between IP addresses and Internet
   hostnames.  Obvious reasons aside, they are mostly useful when you know
   which of the two the input will be.  They return nothing if the address
   could not be converted, or if the input was invalid.  The $convert()
   function should be used if the input is known to vary.

Returns:
   iptoname: hostname for the given IP address
   nametoip: IP address for the given hostname

Examples:
   $iptoname(127.0.0.1)         probably returns "localhost"
   $nametoip(localhost)         probably returns "127.0.0.1"
   $iptoname(localhost)         error, input is not an IP address
   $nametoip(127.0.0.1)         error, input is not a hostname

See Also:
   convert(6)

