1: package Acme::Bleach;
2: $VERSION = '1.12';
3: my $tie = " \t"x8;
4:sub whiten { local $_ = unpack "b*", pop; tr/01/ \t/; s/(.{9})/$1\n/g; $tie.$_ }
5: sub brighten { local $_ = pop; s/^$tie|[^ \t]//g; tr/ \t/01/; pack "b*", $_ }
6: sub dirty { $_[0] =~ /\S/ }
7: sub dress { $_[0] =~ /^$tie/ }
8: open 0 or print "Can't rebleach '$0'\n" and exit;
9: (my $shirt = join "", <0>) =~ s/.*^\s*use\s+Acme::Bleach\s*;\n//sm;
10: local $SIG{__WARN__} = \&dirty;
11: do {eval brighten $shirt; exit} unless dirty $shirt && not dress $shirt;
12: open 0, ">$0" or print "Cannot bleach '$0'\n" and exit;
13: print {0} "use Acme::Bleach;\n", whiten $shirt and exit;