http://www.perlmonks.org?node_id=932918

etheral has asked for the wisdom of the Perl Monks concerning the following question:

use strict; use warnings; no warnings 'recursion'; use Pod::Usage; use English qw( -no_match_vars ); use Getopt::Long qw(:config no_ignore_case no_auto_abbrev pass_through +); $OUTPUT_AUTOFLUSH = 1; #################################################################### ## OPTIONS #################################################################### GetOptions( "help|h!" => \my $help, ) or pod2usage(verbose => 0,exitstatus => 1); if ($help) { pod2usage(verbose => 2,exitstatus => 0); exit; } #################################################################### ## MAIN #################################################################### my @array = (1 .. 150); my $array_size = size_of_an_array(@array); print "Size of this array is $array_size\n"; exit; #################################################################### ## SUBS #################################################################### sub size_of_an_array { my(@array) = @_; if (not @array) { return 0; } else { pop @array; return (1 + size_of_an_array(@array)); } }

This code works ok because I removed recursion warning (line on top of the code). If I allow recursion warning and my array is (1 .. 98) I get no warnings. If my array is larger I get Deep recursion on subroutine "main::size_of_an_array" at ./recursive_array_ex11.8.pl line 91.. On the net I found it has something to do with perl's depth limit being 100, and that there is a $DB:deep variable that allows you to change this depth. But I can't figure how it works, could you help me solve this problem (I'd like to have a very large array, use this recursive subroutine, and get no warnings)