(PECL xdiff >= 0.2.0)
Make unified diff of two strings
string xdiff_string_diff ( string $old_data, string $new_data [, int $context = 3 [, bool $minimal = false ]] )
Makes an unified diff containing differences between old_data string and new_data string and returns it. The resulting diff is human-readable. An optional context parameter specifies how many lines of context should be added around each change. Setting min