use strict;

my $ret = `ps v $$`;
print "$ret\n";

for ( 1 .. 1000 ){
  my $key = ':PERSON-NUM(1:*):NI-NUM(1:*):';
  for my $bb ( "PERSON-NUM", "NI-NUM" ){
     if ( $key =~ /:$bb *\( *([0-9]+) *: *([0-9\*]+) *\) *:/ ){
        $key =~ s/:$bb *\( *[0-9]+ *: *[0-9\*]+ *\) *:/:$bb=1:/;
       }
    }
 }


$ret = `ps v $$`;
print "$ret\n";
[download]

I ran your code with the loop iterator set 1e6, and see no memory growth under either 5.8.6 or 5.8.8.

I seem to recall that 5.8.2 (the version shown in your OP), was a particularly buggy, short-lived release. I strongly suggest you try upgrading to something newer. My memory tells me that 5.8.3 was a pretty good build as is 5.8.6 which I still use as my default install. I encountered a few problems with 5.8.8 but I think they may have been limited to the AS-Win distribution I use.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.