$padded = sprintf("%${pad_len}s", $text);

##</code><code>##

$padded = sprintf("%04d", $text);

##</code><code>##

#!/usr/bin/perl -w
use strict;

my $string1 = "12345";      # 5 character string
my $string2 = "1234567890"; # 10 character string

my $pad_len = 10;

my $padded1 = sprintf("%${pad_len}s", $string1);
my $padded2 = sprintf("%${pad_len}s", $string2);

print "|$padded1|\n|$padded2|\n";

##</code><code>##

|     12345|
|1234567890|