sub human_size {
    my $val = shift;
    # 2**10 (binary) multiplier by default
    my $multiplier = @_ ? shift : 1024;

    my $magnitude = 0;
    my @suffixes = qw/B KB MB GB TB PB EB/;

    my $rval;

    while (($rval = sprintf("%.2f",$val)) >= $multiplier) {
        $val /= $multiplier;
        $magnitude++;
    }

    # Use Perl's numeric conversion to remove trailing zeros
    # in the fraction and the decimal point if unnecessary
    $rval = 0 + $rval;

    if(wantarray) {
        ($rval, $magnitude, $suffixes[$magnitude]);
    } else {
        "$rval $suffixes[$magnitude]";
    }
}


##
## Example code below
##


# read value from the command line

my $val = shift;

# Scalar context example

printf "Size: %s\n", scalar human_size($val);

# List context example

my @fancy_suffixes = map "${_}bytes", '', qw/kilo mega giga tera peta 
+exa/;

my ($hval, $mag, $sfx) = human_size($val, 10**3);

$hval .= ' decimal' if $mag; # omit for values < 1KB
$hval = "$hval $fancy_suffixes[$mag] ($sfx)";

print "Size: $hval\n";
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