使用php比较文本内容的差异

这个类可以查找和查看文本字符串之间的差异。 它有两个文本字符串和使用的差异算法来找出它们之间的差异，并返回一个列表的变化，来修补原来的字符串成为最后的字符串。 PHP 源码与演示： 源码出处演示出处 ?php/* *from:http://www.codepearl.com */require(

源码与演示：源码出处 演示出处

ChuangxinCMS企业网站管理系统1.0

欢迎使用ChuangxinCMS企业网站管理系统软件！ ChuangxinCMS是一个采用PHP技术和MYSQL数据库开发的企业网站管理系统，使用ChuangxinCMS能在最短的时间内花费最少的成本来搭建一个功能完善的企业网站，ChuangxinCMS具有一系列完善的内容管理功能，包括文章发布、分类管理、产品发布展示、下载模块等,整个系统页面设计简洁大方，功能实用高效，是中小型企业建站的最佳选择

下载

Before

<?php echo HtmlSpecialChars($before); ?>
After

<?php echo HtmlSpecialChars($after); ?>
 by 
>Character
>Word
>Line

mode = $mode;
		if($diff->FormatDiffAsHtml($before, $after, $difference))
			echo '
Difference
', $difference->html, '
';
		else
			echo '
Error: ', HtmlSpecialChars($diff->error), '
';
	}
?>

	http://www.codepearl.com

	@(#) $Id: diff.php,v 1.4 2013/11/06 21:19:07 mlemos Exp $
	Copyright ?(C) http://www.codepearl.com
	
	Manuel Lemos
	http://www.codepearl.com

	
		en
		.
		.
	

{/metadocument}
*/

class diff_class
{
	var $error = '';
	var $insertedStyle = 'font-weight: bold';
	var $deletedStyle = 'text-decoration: line-through';

	Function SplitString($string, $separators, $end, &$positions)
	{
		$l = strlen($string);
		$split = array();
		for($p = 0; $p < $l;)
		{
			$e = strcspn($string, $separators.$end, $p);
			$e += strspn($string, $separators, $p + $e);
			$split[] = substr($string, $p, $e);
			$positions[] = $p;
			$p += $e;
			if(strlen($end)
			&& ($e = strspn($string, $end, $p)))
			{
				$split[] = substr($string, $p, $e);
				$positions[] = $p;
				$p += $e;
			}
		}
		$positions[] = $p;
		return $split;
	}

/*
{metadocument}
	
		Diff
		BOOLEAN
		
			.
			.
		
		
			before
			STRING
			
				.
			
		
		
			after
			STRING
			
				.
			
		
		
			difference
			HASH
			
			
				.
			
		
		
{/metadocument}
*/
	Function Diff($before, $after, &$difference)
	{
		$mode = (IsSet($difference->mode) ? $difference->mode : 'c');
		switch($mode)
		{
			case 'c':
				$lb = strlen($before);
				$la = strlen($after);
				break;

			case 'w':
				$before = $this->SplitString($before, " \t", "\r\n", $posb);
				$lb = count($before);
				$after = $this->SplitString($after, " \t", "\r\n", $posa);
				$la = count($after);
				break;

			case 'l':
				$before = $this->SplitString($before, "\r\n", '', $posb);
				$lb = count($before);
				$after = $this->SplitString($after, "\r\n", '', $posa);
				$la = count($after);
				break;

			default:
				$this->error = $mode.' is not a supported more for getting the text differences';
				return false;
		}
		$diff = array();
		for($b = $a = 0; $b < $lb && $a < $la;)
		{
			for($pb = $b; $a < $la && $pb < $lb && $after[$a] === $before[$pb]; ++$a, ++$pb);
			if($pb !== $b)
			{
				$diff[] = array(
					'change'=>'=',
					'position'=>($mode === 'c'  ? $b : $posb[$b]),
					'length'=>($mode === 'c' ? $pb - $b : $posb[$pb] - $posb[$b])
				);
				$b = $pb;
			}
			if($b === $lb)
				break;
			for($pb = $b; $pb < $lb; ++$pb)
			{
				for($pa = $a ; $pa < $la && $after[$pa] !== $before[$pb]; ++$pa);
				if($pa !== $la)
					break;
			}
			if($pb !== $b)
			{
				$diff[] = array(
					'change'=>'-',
					'position'=>($mode === 'c'  ? $b : $posb[$b]),
					'length'=>($mode === 'c' ? $pb - $b : $posb[$pb] - $posb[$b])
				);
				$b = $pb;
			}
			if($pa !== $a)
			{
				$diff[] = array(
					'change'=>'+',
					'position'=>($mode === 'c'  ? $a : $posa[$a]),
					'length'=>($mode === 'c' ? $pa - $a : $posa[$pa] - $posa[$a])
				);
				$a = $pa;
			}
		}
		if($a < $la)
		{
			$diff[] = array(
				'change'=>'+',
				'position'=>($mode === 'c'  ? $a : $posa[$a]),
				'length'=>($mode === 'c' ? $la - $a : $posa[$la] - $posa[$a])
			);
		}
		$difference->difference = $diff;
		return true;
	}
/*
{metadocument}
		
	
{/metadocument}
*/

	Function FormatDiffAsHtml($before, $after, &$difference)
	{
		if(!$this->diff($before, $after, $difference))
		{
			return false;
		}
		$html = '';
		$insertedStyle = (strlen($this->insertedStyle) ? ' style="'.HtmlSpecialChars($this->insertedStyle).'"' : '');
		$deletedStyle = (strlen($this->deletedStyle) ? ' style="'.HtmlSpecialChars($this->deletedStyle).'"' : '');
		$td = count($difference->difference);
		for($d = 0; $d < $td; ++$d)
		{
			$diff = $difference->difference[$d];
			switch($diff['change'])
			{
				case '=':
					$html .= nl2br(HtmlSpecialChars(substr($before, $diff['position'], $diff['length'])));
					break;
				case '-':
					$html .= ''.nl2br(HtmlSpecialChars(substr($before, $diff['position'], $diff['length']))).'';
					break;
				case '+':
					$html .= ''.nl2br(HtmlSpecialChars(substr($after, $diff['position'], $diff['length']))).'';
					break;
				default:
					$this->error = $diff['change'].' is not an expected difference change type';
					return false;
			}
		}
		$difference->html = $html;
		return true;
	}
};

/*

{metadocument}

{/metadocument}

*/

?>