SIMPLE DIFF ENTRE 2 FICHIERS

<?php
/**
* function fileDiff ()
* checks differences between 2 files : additions, suppressions and modifications
* @Param (string) sFileOriginal : the original filename
* @Param (string) sFileModified : the modified filename
* @Return (mixed) : false (boolean) if failed, (array) aDiff with differences if succeeded
*/
function fileDiff ($sFileOriginal, $sFileModified) {
	/**
	* checks that the files are accessible. If not, exit.
	*/
	if (!file_exists ($sFileOriginal) || !file_exists ($sFileModified)) {
		return false;
	}
	/**
	* gets the content of each file in an array, each entry being a line of the file
	*/
	$aFirst = file ($sFileOriginal);
	$aLast = file ($sFileModified);
	/**
	* gets the biggest value between the size of both the arrays
	*/
	$iMax = max (count ($aFirst), count ($aLast));
	/**
	* creates a callback function to remove any \r\n\t or space at the end or the beginninh of the line
	*/
	$myTrim = create_function ('$val', 'return trim ($val);');
	/**
	* removes the empty entries in both the arrays, without touching the indexes
	*/
	$aFirst = array_filter (array_map ($myTrim, $aFirst));
	$aLast = array_filter (array_map ($myTrim, $aLast));
	/**
	* declaration of the aDiff array
	*/
	$aDiff = array ();
	/**
	* loops on both the arrays, to the end of the biggest one
	*/
	for ($i = 0; $i < $iMax; $i++) {
		if (isset ($aFirst[$i])) {
			if (isset ($aLast[$i])) {
				if ($aFirst[$i] !== $aLast[$i]) {
					/**
					* both entries exists and are different, so, it's a modification
					*/
					$aDiff[$i]['MODIFIED'] = htmlentities ($aLast[$i]);
				}
			} else {
				/**
				* there is an original entry, but nothing in the modified file, so, it's a suppression
				*/
				$aDiff[$i]['SUPPR'] = htmlentities ($aFirst[$i]);
			}
		} else {
			if (isset ($aLast[$i])) {
				/**
				* there is a modified entry but no corresponding original entry, so, it's an addition
				*/
				$aDiff[$i]['ADDED'] = htmlentities ($aLast[$i]);
			}
		}
	}
	return $aDiff;
}

$sFirst = 'test.php';
$sLast = 'test2.php';

$aDiff = fileDiff ($sFirst, $sLast);

foreach ($aDiff as $clef => $val) {
	echo 'LIGNE ', $clef+1, ' : ';
	switch (key ($val)) {
		case 'MODIFIED' :
			echo '<span style="color: #0000ff;">',$val['MODIFIED'],'</span><br />';
			break;
		case 'SUPPR' :
			echo '<span style="color: #ff0000;">',$val['SUPPR'],'</span><br />';
			break;
		case 'ADDED' :
			echo '<span style="color: #00ff00;">',$val['ADDED'],'</span><br />';
			break;
	}
}
?>