A bit late, I imagine, but here's another way of doing it if the aim, as it appears to be, is just to convert the input string into a number:

use strict;
use warnings;

my %convert = ( KB => 10,
                MB => 20,
                GB => 30 );
my $num;
{
   print "Enter the block size\n (example: 400KB,10MB,1GB): ";
   my $block_size = uc <STDIN>;
   print "Invalid block type specified!\n\n" and redo
      unless $block_size =~ /^(\d+)([KMG]B)$/;
   $num = $1 * 2 ** $convert{$2};
}
print $num;

[download]

dave

In reply to Re: why is this code bad under -w option? by Not_a_Number
in thread why is this code bad under -w option? by Grygonos

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