Every line that has $1 on it has an uninitialized value, and it's not $1. This isn't your real program though; this doesn't get past use strict since you haven't declared the variables, and you've got a couple of syntax errors. Perhaps your test program was supposed to be:

use strict; 
use warnings; 

$_ = "ArraySize 4285";

my $luns_per_array = 10;
my $logical_size; # useless variable?

if ( /^ArraySize (.+)/ ) 
    { 
    print "\nArray: " . $1 . " yields a LUN of " . int($1/$luns_per_ar
+ray) . "GB\n" ; 

    $logical_size = int($1/2); 
    
    if ( ( $logical_size * $luns_per_array ) == $1 ) 
        {
        {$logical_size--;} 
        }
    }
[download]

Perhaps your regular expression is not matching anything, leaving $1 uninitialized?

If the string is at the beginning of the line: you have the '^' at the beginning your regex. You also have to make sure that what you think is a single space is really a single space. Try changing the space in the regex to, say, '\s+' to match any kind and amount of white space. There are probably other things that could go wrong that I haven't thought of...

non-Perl: Andy Ford

I might try answering your question once you have formatted your OP as suggested by eff_i_g below.

Until then, I'm afraid, I just don't understand it.