... | perl -pe 'BEGIN { $|=1; } s/\Qhide_me/removed/ig' | tee -a test.log

##</code><code>##

... | censor_passwd | tee -a test.log

##</code><code>##

#!/usr/bin/perl

# censor_passwd

use warnings;
use strict;

my $password = "hide_me";

$| = 1;

while (<STDIN>) {
   s/\Q$password/removed/ig;
   print;
}