PHP函数preg_match_all()的相关使用方法介绍_PHP教程

<ol class="dp-xml"><li class="alt"><span><span class="tag"><</span><span> ?php  </span></span></li><li><span>//功能：将文本中的链接地址转成HTML  </span></li><li class="alt"><span>//输入：字符串  </span></li><li><span>//输出：字符串  </span></li><li class="alt"><span>function url2html($text)  </span></li><li><span>{  </span></li><li class="alt"><span>//匹配一个URL，直到出现空白为止  </span></li><li><span>preg_match_all("/http://?[^s]+/i"<br />, $text, $links);  </span></li><li class="alt"><span>//设置页面显示URL地址的长度  </span></li><li><span>$</span><span class="attribute">max_size</span><span> = </span><span class="attribute-value">40</span><span>;  </span></li><li class="alt"><span>foreach($links[0] as $link_url)  </span></li><li><span>{  </span></li><li class="alt"><span>//计算URL的长度。如果超过$max_size的设置，则缩短。  </span></li><li><span>$</span><span class="attribute">len</span><span> = </span><span class="attribute-value">strlen</span><span>($link_url);  </span></li><li class="alt"><span>if($len </span><span class="tag">></span><span> $max_size)   </span></li><li><span>{  </span></li><li class="alt"><span>$</span><span class="attribute">link_text</span><span> = </span><span class="attribute-value">substr</span><span>($link_url, 0, $max_size)."...";  </span></li><li><span>} else {  </span></li><li class="alt"><span>$</span><span class="attribute">link_text</span><span> = $link_url;  </span></li><li><span>}  </span></li><li class="alt"><span>//生成HTML文字  </span></li><li><span>$</span><span class="attribute">text</span><span> = </span><span class="attribute-value">str_replace</span><span>($link_url,"<br /></span><span class="tag"><</span><span> </span><span class="tag-name">a</span><span> </span><span class="attribute">href</span><span>=</span><span class="attribute-value">'$link_url'</span><span class="tag">></span><span>$link_text</span><span class="tag"></</span><span class="tag-name">a</span><span class="tag">></span><span>",$text);  </span></li><li class="alt"><span>}  </span></li><li><span>return $text;  </span></li><li class="alt"><span>}  </span></li><li><span>//运行实例  </span></li><li class="alt"><span>$</span><span class="attribute">str</span><span> = “这是一个包含多个URL链接地址的多行文字。<br />欢迎访问http://www.taoboor.com”;  </span></li><li><span>print url2html($str);  </span></li><li class="alt"><span>/*输出结果  </span></li><li><span>这是一个包含多个URL链接地址的多行文字<br />。欢迎访问</span><span class="tag"><</span><span> </span><span class="tag-name">a</span><span> </span><span class="attribute">href</span><span>=</span><span class="attribute-value">'http://www.taoboor.com'</span><span class="tag">></span><span> </span></li><li class="alt"><span>http://www.taoboor.com</span><span class="tag"></</span><span class="tag-name">a</span><span class="tag">></span><span> </span></li><li><span>*/  </span></li><li class="alt"><span class="tag">?></span><span> </span></li></ol>