Rename Enron E-mail corpus to Windows-friendly filename

enron-rename.pl

#!/usr/bin/perl -w
use File::Spec::Functions qw/catfile/;
use strict;

sub recurse
{
	my $root = shift;
	opendir my $dir, $root or die "Cannot open directory: '$root': $!\n";
	for my $file(readdir $dir)
	{
		if((-d catfile($root, $file)) && ($file ne ".") && ($file ne ".."))
		{
			recurse(catfile($root, $file));
		}
		elsif((-f catfile($root, $file)) && ($file =~ /^\d+\.$/))
		{
			rename catfile($root, $file), catfile($root, $file . "txt");
		}
	}
}

if(-d $ARGV[0]) { recurse $ARGV[0] } else { die "Not a directory: '$ARGV[0]'\n" }