I was needing to use exif_read_data() to read out the orientation flag, only to find that the webhost didn't have the exif extension available for use. Instead, I hacked up a regex that worked fairly well as a replacement
<?php
$orientation = 1;
if (function_exists('exif_read_data')) {
$exif = exif_read_data($filename);
if (isset($exif['Orientation']))
$orientation = $exif['Orientation'];
} else if (preg_match('@\x12\x01\x03\x00\x01\x00\x00\x00(.)\x00\x00\x00@', file_get_contents($filename), $matches)) {
$orientation = ord($matches[1]);
}
?>
