package Acme::Bleach; $VERSION = '1.12'; my $tie = " \t" x 8; sub whiten { local $_ = unpack "b*", pop; tr/01/ \t/; s/(.{9})/$1\n/g; $tie . $_; } sub brighten { local $_ = pop; s/^$tie|[^ \t]//g; tr/ \t/01/; pack "b*", $_; } sub dirty { $_[0] =~ /\S/; } sub dress { $_[0] =~ /^$tie/; } open 0 or print "Can't rebleach '$0'\n" and exit; ( my $shirt = join "", <0> ) =~ s/.*^\s*use\s+Acme::Bleach\s*;\n//sm; local $SIG{__WARN__} = \&dirty; do { eval brighten $shirt; exit } unless dirty $shirt && not dress $shirt; open 0, ">$0" or print "Cannot bleach '$0'\n" and exit; print {0} "use Acme::Bleach;\n", whiten $shirt and exit;