Question

I need to create an “obscuring” function which replaces a clear-text password in line, before writing it to a log.

It looks like this:

function pass_obscure {
      my $logline = shift;
      my $pass = "wer32pass$";   # This password is an example. The real one is received as a parameter, or already stored as a global value.

      $logline =~ s/$pass/*********/g;

      return $logline;
}

But this, of course, doesn’t work. The ‘$’ sign in the password string is interpolated as an endline character, so there’s no match, and so replacement doesn’t work.

How can I resolve this?

Answer 1

(Why not just keep the password out of the log line in the first place?)

Use quotemeta:

$pass = "password\$";
$logline = "password is: password\$";

print "$pass\n";
print "$logline\n";
$pass_quoted = quotemeta($pass);

$logline =~ s/$pass_quoted/********/g;

print "$logline\n";

Outputs:

password$
password is: password$
password is: ********