<?php
$a = $b = range(0,10);
$f1 = tempnam('/tmp','differ_');
file_put_contents($f1,var_export($a,true));
$f2 = tempnam('/tmp','differ_');
file_put_contents($f2,var_export($b,true));
echo `wdiff $f1 $f2`;
unlink($f1);
unlink($f2);
?>