javascript - Stuck on Converting a JS function to Perl -

im trying convert this: (js function) perl.

decrypt3 = function (strin, strkey) {   var strout = new string();   var lenin = strin.length;   var lenkey = strkey.length;   var = 0;   var numin;   var numkey;   while (i < lenin) {     numin = parseint(strin.substr(i, 2), 32);     numkey = strkey.charcodeat(i / 2 % lenkey);     strout += string.fromcharcode(numin - numkey);     += 2;   }   return strout; }; 

this far have come: im not sure how strout , correct numkey.

    while (<>) {   chomp;   print decrypt3($_, $key),"\n"; }   sub decrypt3 {     @str_in  = unpack 'c*', shift;     @str_key = unpack 'c*', shift;     @str_out;      $i (0 .. $str_in) {         $numin = int[$str_in[ord[$i 2], 32]         $sum = $str_in[$i] + $str_key[$i / 2% @str_key]; 

use list::util 1.29 qw( pairmap );  @base32_syms = (0..9, 'a'..'v'); %base32_sym_vals =    map {       lc($base32_syms[$_]) => $_,       uc($base32_syms[$_]) => $_,    }       0..$#base32_syms;  sub decrypt3 {    @cypher =       pairmap { $base32_sym_vals{$a} * 32 + $base32_sym_vals{$b} }          split(//, shift);     @key = unpack('c*', shift);     return       join ' ',          map { chr($cypher[$_] - $key[ $_ % @key ]) }             0..$#cypher; }