This functions returns the input string padded on the left, the right, or both sides to the specified padding length. If the optional argument pad_string is not supplied, the input is padded with spaces, otherwise it is padded with characters from pad_string up to the limit.

<?php
$input = "Hello";
echo str_pad($input, 10);                      // produces "Hello     "
echo str_pad($input, 10, "-=", STR_PAD_LEFT);  // produces "-=-=-Hello"
echo str_pad($input, 10, "_", STR_PAD_BOTH);   // produces "__Hello___"
echo str_pad($input, 6 , "___");               // produces "Hello_"
?>