Heim >Backend-Entwicklung >PHP-Tutorial >巧妙运用PHP函数实现采集器_PHP教程
PHP经过长时间的发展,很多用户都很了解PHP了,我们现在可以利用PHP函数实现采集器程序。何为采集器,通常又叫小偷程序,主要是用来抓取别人网页内容的。关于采集器的制作,其实并不难,就是远程打开要采集的网页,然后用正则表达式将需要的内容匹配出来,只要稍微有点正则表达式的基础,都能做出自己的采集器来的。
这样还不够,还需要一个切取PHP函数:
<ol class="dp-xml"> <li class="alt"><span><span>function cut($string,$start,$end){ </span></span></li> <li class=""> <span>$</span><span class="attribute"><font color="#ff0000">message</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">explode</font></span><span>($start,$string); </span> </li> <li class="alt"> <span>$</span><span class="attribute"><font color="#ff0000">message</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">explode</font></span><span>($end,$message[1]); return $message[0];}其中$string为要被切取的内容,$start为开始的地方,$end为结束的地方。取出分类号: </span> </li> <li class=""><span> </span></li> <li class="alt"> <span>$</span><span class="attribute"><font color="#ff0000">start</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">"Html/Book/"</font></span><span>; </span> </li> <li class=""> <span>$</span><span class="attribute"><font color="#ff0000">end</font></span><span> </span> </li> <li class="alt"> <span>= </span><span class="attribute-value"><font color="#0000ff">"List.shtm"</font></span><span>; </span> </li> <li class=""> <span>$</span><span class="attribute"><font color="#ff0000">typeid</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">cut</font></span><span>($typeid[0][0],$start,$end); </span> </li> <li class="alt"> <span>$</span><span class="attribute"><font color="#ff0000">typeid</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">explode</font></span><span>("/",$typeid);[/php] </span> </li> <li class=""><span> </span></li> <li class="alt"><span>这样,$typeid[0]就是我们要找的分类号了。方法如下: </span></li> <li class=""><span> </span></li> <li class="alt"> <span>$</span><span class="attribute"><font color="#ff0000">ustart</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">""</font></span><span>"; </span> </li> <li class=""> <span>$</span><span class="attribute"><font color="#ff0000">uend</font></span><span> </span> </li> <li class="alt"> <span>= </span><span class="attribute-value"><font color="#0000ff">""</font></span><span>"; </span> </li> <li class=""><span>//t表示title的缩写 </span></li> <li class="alt"> <span>$</span><span class="attribute"><font color="#ff0000">tstart</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">">"</font></span><span>; </span> </li> <li class=""> <span>$</span><span class="attribute"><font color="#ff0000">tend</font></span><span> </span> </li> <li class="alt"> <span>= </span><span class="attribute-value"><font color="#0000ff">"</font></span><span>; </span> </li> <li class=""><span>//取路径,例如:123.shtm,2342.shtm,233.shtm </span></li> <li class="alt"><span>preg_match_all("/"[0-9]{1,}.(shtm)"/is",$chapterurl,$url); </span></li> <li class=""><span>//取标题,例如:第一章 九世善人 </span></li> <li class="alt"> <span>preg_match_all("/</span><strong><font color="#006699"><span class="tag"><span class="tag-name">a</span></span></font></strong><span> </span><span class="attribute"><font color="#ff0000">href</font></span><span>="[0-9]{1,}.shtm"(.*?)</span><span class="tag"><strong><font color="#006699"></font></strong></span><span>/a</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>/is",$file,$title); </span> </li> <li class=""> <span>$</span><span class="attribute-value"><font color="#0000ff">count</font></span><span class="attribute"><font color="#ff0000">countcount</font></span><span> = count($url[0]); </span> </li> <li class="alt"> <span>for($</span><span class="attribute"><font color="#ff0000">i</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">0</font></span><span>;$i</span><span class="tag"><strong><font color="#006699"></font></strong></span><span>=$count;$i++) </span> </li> <li class=""><span>{ </span></li> <li class="alt"> <span>$</span><span class="attribute"><font color="#ff0000">u</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">cut</font></span><span>($url[0][$i],$ustart,$uend); </span> </li> <li class=""> <span>$</span><span class="attribute"><font color="#ff0000">t</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">cut</font></span><span>($title[0][$i],$tstart,$tend); </span> </li> <li class="alt"><span>$array[$u] = $t; </span></li> <li class=""><span>} </span></li> </ol>
$array数组就是所有的章节地址了,到这里,采集器就完成一半了,剩下的就是循环打开每个章节地址,读取,然后将内容匹配出来。这个比较简单,这里就不详细叙述了。好了,今天就先写到这吧,第一次写这么长的文章,语言组织方面难免有问题,还请大家多包涵!