<?php
/**
* Class used internally by Diff to actually compute the diffs.
*
* This class uses the Unix `diff` program via shell_exec to compute the
* differences between the two input arrays.
*
* Copyright 2007-2010 The Horde Project (http://www.horde.org/)
*
* See the enclosed file COPYING for license information (LGPL). If you did
* not receive this file, see https://opensource.org/license/lgpl-2-1/.
*
* @author Milian Wolff <mail@milianw.de>
* @package Text_Diff
* @since 0.3.0
*/
class Text_Diff_Engine_shell {
/**
* Path to the diff executable
*
* @var string
*/
var $_diffCommand = 'diff';
/**
* Returns the array of differences.
*
* @param array $from_lines lines of text from old file
* @param array $to_lines lines of text from new file
*
* @return array all changes made (array with Text_Diff_Op_* objects)
*/
function diff($from_lines, $to_lines)
{
array_walk($from_lines, array('Text_Diff', 'trimNewlines'));
array_walk($to_lines, array('Text_Diff', 'trimNewlines'));
$temp_dir = Text_Diff::_getTempDir();
// Execute gnu diff or similar to get a standard diff file.
$from_file = tempnam($temp_dir, 'Text_Diff');
$to_file = tempnam($temp_dir, 'Text_Diff');
$fp = fopen($from_file, 'w');
fwrite($fp, implode("\n", $from_lines));
fclose($fp);
$fp = fopen($to_file, 'w');
fwrite($fp, implode("\n", $to_lines));
fclose($fp);
$diff = shell_exec($this->_diffCommand . ' ' . $from_file . ' ' . $to_file);
unlink($from_file);
unlink($to_file);
if (is_null($diff)) {
// No changes were made
return array(new Text_Diff_Op_copy($from_lines));
}
$from_line_no = 1;
$to_line_no = 1;
$edits = array();
// Get changed lines by parsing something like:
// 0a1,2
// 1,2c4,6
// 1,5d6
preg_match_all('#^(\d+)(?:,(\d+))?([adc])(\d+)(?:,(\d+))?$#m', $diff,
$matches, PREG_SET_ORDER);
foreach ($matches as $match) {
if (!isset($match[5])) {
// This paren is not set every time (see regex).
$match[5] = false;
}
if ($match[3] == 'a') {
$from_line_no--;
}
if ($match[3] == 'd') {
$to_line_no--;
}
if ($from_line_no < $match[1] || $to_line_no < $match[4]) {
// copied lines
assert($match[1] - $from_line_no == $match[4] - $to_line_no);
array_push($edits,
new Text_Diff_Op_copy(
$this->_getLines($from_lines, $from_line_no, $match[1] - 1),
$this->_getLines($to_lines, $to_line_no, $match[4] - 1)));
}
switch ($match[3]) {
case 'd':
// deleted lines
array_push($edits,
new Text_Diff_Op_delete(
$this->_getLines($from_lines, $from_line_no, $match[2])));
$to_line_no++;
break;
case 'c':
// changed lines
array_push($edits,
new Text_Diff_Op_change(
$this->_getLines($from_lines, $from_line_no, $match[2]),
$this->_getLines($to_lines, $to_line_no, $match[5])));
break;
case 'a':
// added lines
array_push($edits,
new Text_Diff_Op_add(
$this->_getLines($to_lines, $to_line_no, $match[5])));
$from_line_no++;
break;
}
}
if (!empty($from_lines)) {
// Some lines might still be pending. Add them as copied
array_push($edits,
new Text_Diff_Op_copy(
$this->_getLines($from_lines, $from_line_no,
$from_line_no + count($from_lines) - 1),
$this->_getLines($to_lines, $to_line_no,
$to_line_no + count($to_lines) - 1)));
}
return $edits;
}
/**
* Get lines from either the old or new text
*
* @access private
*
* @param array $text_lines Either $from_lines or $to_lines (passed by reference).
* @param int $line_no Current line number (passed by reference).
* @param int $end Optional end line, when we want to chop more
* than one line.
*
* @return array The chopped lines
*/
function _getLines(&$text_lines, &$line_no, $end = false)
{
if (!empty($end)) {
$lines = array();
// We can shift even more
while ($line_no <= $end) {
array_push($lines, array_shift($text_lines));
$line_no++;
}
} else {
$lines = array(array_shift($text_lines));
$line_no++;
}
return $lines;
}
}
في جولة حصرية داخل “الغرفة الزرقاء” بقناة BBC العربية، نكشف كواليس واحدة من أكثر غرف الأخبار تطورًا في العالم.
كيف الذكاء اصطناعي يتحكم بالبث دون تدخل بشري، لتقدم تجربة بصرية مذهلة.
الفيديو يستعرض كيف تمزج BBC بين التقنية والاحتراف لتصنع نشرات إخبارية من قلب المستقبل.