#! perl -lw
use strict;
use Data::Dumper;

BEGIN{
	our %channels;
	my $channel;
	while( @ARGV ) {
		$_ = shift @ARGV;
		if( m[-channel] ) {
			$channel = shift @ARGV;
			push @{ $channels{ $channel } }, {};
			next ;
		}
		if( m[-([a-z])] ) {
			$channels{ $channel }[-1]{ $1 } = shift @ARGV;
			next;
             }
		die "Invalid arg '$_'";
	}
}

our %channels;
print Dumper \%channels;

__DATA__
P:\test>perl 456642.pl -channel 1 -a 1 -b 1 -c 1 -channel 2 -a 2 -c 2 -channel 3 -b 3 -c 17 -channel 1 -a 2 -c 2
$VAR1 = {
          '1' => [
                   {
                     'c' => '1',
                     'a' => '1',
                     'b' => '1'
                   },
                   {
                     'c' => '2',
                     'a' => '2'
                   }
                 ],
          '3' => [
                   {
                     'c' => '17',
                     'b' => '3'
                   }
                 ],
          '2' => [
                   {
                     'c' => '2',
                     'a' => '2'
                   }
                 ]
        };