freebsd-dev/gnu/usr.bin/perl/lib/gethostname.pl
1997-02-22 15:48:31 +00:00

37 lines
811 B
Perl

#
# Simple package to get the hostname via __sysctl(2).
#
# Written 13-Feb-96 by Jörg Wunsch, interface business GmbH Dresden.
# Placed in the public domain.
#
# $Id$
#
package gethostname;
require "sys/syscall.ph";
require "sys/sysctl.ph";
#
# usage:
#
# require "gethostname.pl";
# printf "This machine is named \"%s\".\n", &gethostname;
#
sub main'gethostname {
# get hostname via sysctl(2)
local($name, $oldval, $oldlen, $len);
$name = pack("LL", &CTL_KERN, &KERN_HOSTNAME);
# 64-byte string to get the hostname
$oldval = " " x 64;
$oldlen = pack("L", length($oldval));
syscall(&SYS___sysctl, $name, 2, $oldval, $oldlen, 0, 0) != -1 ||
die "Cannot get hostname via sysctl(2), errno = $!\n";
($len) = unpack("L", $oldlen);
return substr($oldval, 0, $len - 1);
}
1;