#! perl -slw
use strict;

my( %users, @linux, @win32 );
my @pcs = (
	[ 'win32', 'dave' ],
	[ 'linux', 'john' ],
	[ 'win32', 'robin' ],
);

for( 0 .. $#pcs ) {
	my $pc = $pcs[ $_ ];
	$users{ $pc->[1] } = $_;
	push @{ $pc->[0] eq 'linux' ? \@linux : \@win32 }, $_;
}

print 'Linux users: ', join ' '
	, map{ $_->[1] } @pcs[ @linux ];
print "Dave's pc is number $users{ dave } attributes:"
	, join ' ', @{ $pcs[ $users{ dave } ] };
print "Win32 pc numbers: @win32\n\t"
	, join "\n\t", map{ join ':', @$_ } @pcs[ @win32 ];

__END__
Linux users: john
Dave's pc is number 0 attributes:win32 dave
Win32 pc numbers: 0 2
        win32:dave
        win32:robin