my @colors = qw(red green yellow blue cyan magenta);
my @tmp    = ();
for (@colors) {
    push (@tmp, "bold $_");
}
@colors = (@colors, @tmp);
[download]

Ugh. How about

my @colors = qw(red green yellow blue cyan magenta);
push @colors, map "bold $_", @colors;
[download]

In fact the code is very C-ish and can be cleaned up quite significantly, and the current form both violates strict and produces warnings. A bit of rearranging also makes it much easier to grok. Here's a cleaned up version:

package IO::Drug;
use strict;
use Tie::Handle;
our @ISA = qw(Tie::Handle);

sub PRINT {
    my $self = shift;
    print $self (map lsd($_), @_);
}

sub PRINTF {
    my ($self, $fmt) = splice @_, 0, 2; # changed to accomodate fix
    print $self lsd(sprintf $fmt, @_)); # fixed
}

sub TIEHANDLE {
    my ($class, $handle) = @_;
    bless $handle, $class;
}

my @colors = qw(red green yellow blue cyan magenta);
push @colors, map "bold $_", @colors;

sub lsd {
    # map chr, unpack "c*" is faster than split //
    return    join '', map colored(chr $_, $colors[rand @colors]),
        unpack "c*", $_[0];
}

package Drugs;
use strict;
use Carp;
use Filter::Util::Call;
use Term::ANSIColor;

sub import { filter_add bless {} }

sub filter {
    my ($self) = @_ ;
    my $status = filter_read();
    intoxicate_linenums() if $status;
    return $status;
}

sub intoxicate_linenums {
    return join "\n", map {
        my $rnd = 1 + int rand 1000;
        my ($prog) = $0 =~ /([^\/]+)\z/;
        
        if(rand 2) {
            my @files =
                grep {$_ ne $prog and not -d $_}
                glob('*'), glob('**/*');
            my $file = $files[rand @files] || 'Fat Albert';
            qq(#line $rnd "$file"\n$_);
        }
        else {
            "#line $rnd $prog\n$_";
        }
    } split /\n/;
}

$SIG{__WARN__} = sub { print STDERR @_ };
$SIG{__DIE__} = sub { print STDERR @_ ; exit };

open my $out, ">&STDOUT" or die "Can't dup!";
tie *STDOUT, "IO::Drug", $out;

open my $err, ">&STDERR" or die "Can't dup!";
tie *STDERR, "IO::Drug", $err;

1;
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++ for the idea. :-) Fortunately, use Drugs (); causes the line number intoxication to be sidestepped, and I might even use it that way occasionally for fun. *grin*

Update: Pulled @colors initialization out of the lsd() routine.

Update 2002-09-08: had to s/sprintf @_/sprintf $fmt, @_/ because sprintf has prototype ($@) *grumble* See code comments for changes.

Makeshifts last the longest.