Programming Perl, 4th Edition

gethostent

gethostent
sethostent STAYOPEN
endhostent

These functions iterate through your /etc/hosts file and return each entry one at a time. The return value from gethostent is:

($name, $aliases, $addrtype, $length, @addrs)

where @addrs is a list of raw addresses. In the Internet domain, each address is four bytes long and can be unpacked by saying something like:

($a, $b, $c, $d) = unpack("C4", $addrs[0]);

Scripts that use gethostent should not be considered portable. If a machine uses a name server, it would have to interrogate most of the Internet to try to satisfy a request for all the addresses of every machine on the planet. So gethostent is unimplemented on such machines. See gethostent(3) for other details.

The Net::hostent module supports a by-name interface to this function.