Format the size of a file (for WordPress)

gistfile1.aw

<?php

/**
 * Return the formatted size of a file.
 *
 * @param string|int $input Either the path to a valid file, or a number in bytes
 * @param string $default_output Optional. The string to output if the input can't be used (e.g. the file doesn't exist)
 * @uses size_format()
 * @return string The size, formatted
 */
function pilau_format_filesize( $input, $default_output = '??' ) {
	$size = null;
	$output = $default_output;
	// Set up some common file size measurements
	$kb = 1024;         // Kilobyte
	$mb = 1024 * $kb;   // Megabyte
	$gb = 1024 * $mb;   // Gigabyte
	$tb = 1024 * $gb;   // Terabyte
	if ( is_file( $input ) ) {
		// Get the file size in bytes
		$size = filesize( $input );
	} else if ( is_numeric( $input ) ) {
		$size = (int) $input;
	}
	if ( $size ) {
		$output = size_format( $size );
	}
	return $output;
}