File size function

This example shows how to format a file and present its size better

<?php
function format_size ($file)
{
//find the filesize of the file
$get_file_size = filesize($file);
//if the filesize has between 7 an 9 characters then its in Mb
if (strlen($get_file_size) <= 9 && strlen($get_file_size) >= 7)
{
$get_file_size = number_format($get_file_size / 1048576,1);
return "$get_file_size MB";
}
//10 characters or over means Gb
elseif (strlen($get_file_size) >= 10)
{
$get_file_size = number_format($get_file_size / 1073741824,1);
return "$get_file_size GB";
}
//anything else is kilobytes
else
{
$get_file_size = number_format($get_file_size / 1024,1);
return "$get_file_size KB";
}
}
?>
<?php

echo format_size("index.htm");
echo "<br>";
echo format_size("monthimages.zip");
echo "<br>";
echo format_size("sampledb.mdb");
?>