use IO::Handle;  # up top

...
    open STDOUT, '>&', $WRITE or die "failed redirect to STDOUT: $!";
    STDOUT->autoflush(1);
...

##</code><code>##

use English qw(-no_match_vars);

...
    open STDOUT, '>&', $WRITE or die "failed redirect to STDOUT: $!";
    $OUTPUT_AUTOFLUSH = 1;
...