I think you just want =~ /\0/ This script will strip out Nulls from a test file.

#!/usr/bin/perl
use warnings;

open(IH,"<null-bytes-test-in") or die $!;
@in = (<IH>);
close IH;

open(OH,"+>null-bytes-test-out");
foreach $line (@in){
$line =~ s/\0//g;
print OH $line;
}
close OH;
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