magnitude.pl

#!/usr/bin/perl

use strict;
use warnings;

my $bignum = 7893420000;
my $nice_form = number_suffix($bignum);
print "$bignum = $nice_form\n";

$bignum = 264340000000;
print "$bignum = ", number_suffix($bignum), "\n";

$bignum = 3460000000000;
number_suffix($bignum);

sub number_suffix
{
    unless ( @_ )
    {
        die "number_suffix needs an argument\n";
    }
    my $n = shift;
    my $suffix = '';
    my @threshold = ( K => 1E3, M => 1E6, G => 1E9, T => 1E12);
    while (my $divisor = pop @threshold )
    {
        my $l = pop @threshold;
        unless ( $n >= $divisor )
        { 
            next;
        }
        $n /= $divisor;
        $suffix = $l;
        last;
    }

    if ( wantarray )
    {
        return ($n, $suffix);
    }
    elsif ( defined(wantarray) )
    {
        return "$n $suffix";
    }
    else
    {
        print "$n $suffix\n";
    }
}