For sure the best thing to do is to open always lexical filehandles to let Perl close them for you. The habit to close them esplicitally is a sane one anyway.

Extra scope can help if you have many declared into the top scope.

But the strange behaviour you announce (leaking file handles like a sieve)

I'd expand the mr_mischief's solution: take count of what you open.

You can override open builtin function very soon in the program or in a BEGIN block, and you can profit of the ${^LAST_FH} special variable: if I understand the doc correctly it tracks the last open $fh (only read-fh ?) taking a reference to it

You probably need to override close to erase from your tracking variable.

An END block can dump the tracking datastructure.

So given a %fhs in the outher scope you can store there your fh

# TOTALLY UNTESTED!!
no warning 'redefine';

my %fhs;

BEGIN {
        *CORE::GLOBAL::open = sub { 
          my ($fh,$mode,$path) = @_;
          
          # open the file
          
          $fhs{fileno($fh)} = $path.' '.${^LAST_FH};
      };
    }


END{
     print "Files already opened:\n", map {"fileno $_ $fhs{$_}\n"} sor
+t keys %fhs;
}
[download]

PS sorry the node was composed on a spare PC where was impossible to test anything..

L*