use strict;
use warnings;
use File::Copy;

File::Copy::copy('Tcl.dll', 'Tcl.dll_bak') or die $!;
open my $infh, '<', 'Tcl.dll' or die $!;
open my $outfh, '>', 'Tcl.dll_new' or die $!;
binmode($infh);
binmode($outfh);
while(<$infh>) {
  $_ =~ s/zlib1\.dll/zxxxx.dll/g;
  print $outfh, $_;
}

##</code><code>##

close $infh;
close $outfh;
my $mode = (stat('Tcl.dll'))[2];
my $newmode = $mode | 0220;
chmod($newmode, 'Tcl.dll');
unlink 'Tcl.dll';
File::Copy::copy( 'Tcl.dll_new', 'Tcl.dll') or die $!;
chmod($mode, 'Tcl.dll');
unlink('Tcl.dll_new');