#!perl
chomp(my $file = `perldoc -l CGI`);
open my $io, "<", $file or die $!;

my $sub;
while (<$io>) {
    chomp;
    /^sub (\w+)/ and $sub = $1;
    /^}\s*$/ and do {
        print "$sub\n" if $code{$sub} =~ /([\%\$]ENV|http\()/; undef $sub
    };
   $code{$sub} .= "$_\n" if $sub;
    /^\s*package [^C]/ and exit;
}
