Listing 8. switch Script

#!/usr/bin/perl -w
# Switch Script written by Ali RB 28th March 2000
##################################################
# This script parses a file /etc/switch.conf
# Syntax for this file is:
# host name	colon separated MAC address e.g.
# p001	00:50:BA:D2:A7:19

# Only an excerpt is listed here, for the whole
#  script see resources

# This routine generates a magic packet to switch
# on a particular machine
# Input is a colon separated Hexadecimal MAC address
# of the target machine
# and the return value is the Magic Packet to be
# broadcast on the network to
# switch it on. Usage: $mpacket =
# generate_magic_packet("11:22:33:44:55:66");

sub generate_magic_packet {
<\n>   
local ($ether) = @_;
local $packet="";
local $hexa ="0123456789ABCDEF";
local $i;
$ccnt = ($ether =~ tr/://);
if (($ccnt != 5) || (length($ether) != 17))
{ return "" };
$ccnt = 0;
for ($i = 0; $i <18; $i = $i + 3) {
   my $a = index( $hexa,uc(substr($ether,$i,1)));
   my $b = index( $hexa,uc(substr($ether,$i+1,1)));
   if (($a<0)||($b<0)) { return ""};
   substr($packet,$ccnt,1) = chr(16 * $a + $b);
   $ccnt++;
}
for ($i = 0; $i <4;$i++) { $packet = $packet.$packet;}
for ($i = 0; $i <6;$i++) { $packet = chr(255).$packet;}
return $packet;
}