IRI::remove_dot_segments( string $input ): string

325    protected function remove_dot_segments(string $input)326    {327        $output = '';328        while (strpos($input, './') !== false || strpos($input, '/.') !== false || $input === '.' || $input === '..') {329            // A: If the input buffer begins with a prefix of "../" or "./", then remove that prefix from the input buffer; otherwise,330            if (strpos($input, '../') === 0) {331                $input = substr($input, 3);332            } elseif (strpos($input, './') === 0) {333                $input = substr($input, 2);334            }335            // B: if the input buffer begins with a prefix of "/./" or "/.", where "." is a complete path segment, then replace that prefix with "/" in the input buffer; otherwise,336            elseif (strpos($input, '/./') === 0) {337                $input = substr($input, 2);338            } elseif ($input === '/.') {339                $input = '/';340            }341            // C: if the input buffer begins with a prefix of "/../" or "/..", where ".." is a complete path segment, then replace that prefix with "/" in the input buffer and remove the last segment and its preceding "/" (if any) from the output buffer; otherwise,342            elseif (strpos($input, '/../') === 0) {343                $input = substr($input, 3);344                $output = substr_replace($output, '', intval(strrpos($output, '/')));345            } elseif ($input === '/..') {346                $input = '/';347                $output = substr_replace($output, '', intval(strrpos($output, '/')));348            }349            // D: if the input buffer consists only of "." or "..", then remove that from the input buffer; otherwise,350            elseif ($input === '.' || $input === '..') {351                $input = '';352            }353            // E: move the first path segment in the input buffer to the end of the output buffer, including the initial "/" character (if any) and any subsequent characters up to, but not including, the next "/" character or the end of the input buffer354            elseif (($pos = strpos($input, '/', 1)) !== false) {355                $output .= substr($input, 0, $pos);356                $input = substr_replace($input, '', 0, $pos);357            } else {358                $output .= $input;359                $input = '';360            }361        }362        return $output . $input;363    }