#!/usr/bin/perl -w
use strict;
use File::Find;
use Tie::File;

find(\&wanted, '/opt/tivoli/itcam/was/DC/');

sub wanted {
    return unless /cynlogging.properties/;
    tie my @file, 'Tie::File', $_ or die "$_: $!\n";
    s/DEBUG_MIN/WARN/g for @file;
    untie @file;
}