Online PHP editor | refs for I6WFv

<?php function concat_path_components($path_components) { $first_component = array_shift($path_components); if ($first_component == NULL) return ""; return array_reduce( $path_components, function ($path, $path_component) { return $path . DIRECTORY_SEPARATOR . $path_component; }, $first_component); } function path_components($path) { $components = array(); while ($path != "." && $path != "/") { array_unshift($components, basename($path)); $path = dirname($path); } if ($path == "/") array_unshift($components, "/"); return $components; } function path_relative_to($path, $rel) { $path_components = path_components($path); $copy = $path_components; $rel_components = path_components($rel); for($i = 0 ; $i < count($rel_components) ; ++$i) { if ($path_components[$i] == $rel[$i]) array_shift($copy); else break; } echo $i . " " . count($rel) . PHP_EOL; if ($i == count($rel_components)) return concat_path_components($copy); else return NULL; } var_dump(path_relative_to("/a/b/c", "/a/b"));