Text_Diff_Engine_shell

17class Text_Diff_Engine_shell {18 19    /**20     * Path to the diff executable21     *22     * @var string23     */24    var $_diffCommand = 'diff';25 26    /**27     * Returns the array of differences.28     *29     * @param array $from_lines lines of text from old file30     * @param array $to_lines   lines of text from new file31     *32     * @return array all changes made (array with Text_Diff_Op_* objects)33     */34    function diff($from_lines, $to_lines)35    {36        array_walk($from_lines, array('Text_Diff', 'trimNewlines'));37        array_walk($to_lines, array('Text_Diff', 'trimNewlines'));38 39        $temp_dir = Text_Diff::_getTempDir();40 41        // Execute gnu diff or similar to get a standard diff file.42        $from_file = tempnam($temp_dir, 'Text_Diff');43        $to_file = tempnam($temp_dir, 'Text_Diff');44        $fp = fopen($from_file, 'w');45        fwrite($fp, implode("\n", $from_lines));46        fclose($fp);47        $fp = fopen($to_file, 'w');48        fwrite($fp, implode("\n", $to_lines));49        fclose($fp);50        $diff = shell_exec($this->_diffCommand . ' ' . $from_file . ' ' . $to_file);51        unlink($from_file);52        unlink($to_file);53 54        if (is_null($diff)) {55            // No changes were made56            return array(new Text_Diff_Op_copy($from_lines));57        }58 59        $from_line_no = 1;60        $to_line_no = 1;61        $edits = array();62 63        // Get changed lines by parsing something like:64        // 0a1,265        // 1,2c4,666        // 1,5d667        preg_match_all('#^(\d+)(?:,(\d+))?([adc])(\d+)(?:,(\d+))?$#m', $diff,68            $matches, PREG_SET_ORDER);69 70        foreach ($matches as $match) {71            if (!isset($match[5])) {72                // This paren is not set every time (see regex).73                $match[5] = false;74            }75 76            if ($match[3] == 'a') {77                $from_line_no--;78            }79 80            if ($match[3] == 'd') {81                $to_line_no--;82            }83 84            if ($from_line_no < $match[1] || $to_line_no < $match[4]) {85                // copied lines86                assert($match[1] - $from_line_no == $match[4] - $to_line_no);87                array_push($edits,88                    new Text_Diff_Op_copy(89                        $this->_getLines($from_lines, $from_line_no, $match[1] - 1),90                        $this->_getLines($to_lines, $to_line_no, $match[4] - 1)));91            }92 93            switch ($match[3]) {94            case 'd':95                // deleted lines96                array_push($edits,