本文将介绍9个经常会用到的PHP代码片段，包括黑名单过滤、随机颜色生成器、从网上下载文件、Alexa/GooglePageRank、强制下载文件、用Email显示用户的Gravator头像、用cURL获取RSS订阅数、截取图片、检查网站是否宕机。
1黑名单过滤functionis_spam($text,$file,$split=:,$regex=false){$handle=fopen($file,rb);$contents=fread($handle,filesize($file));fclose($handle);$lines=explode(n,$contents);$arr=array();foreach($linesas$line){list($word,$count)=explode($split,$line);if($regex)$arr[$word]=$count;else$arr[preg_quote($word)]=$count;}preg_match_all(~.implode(,array_keys($arr)).~,$text,$matches);$temp=array();foreach($matches[0]as$match){if(!in_array($match,$temp)){$temp[$match]=$temp[$match]+1;if($temp[$match]=$arr[$word])returntrue;}}returnfalse;}$file=spam.txt;$str=Thisstringhascat,dogword;if(is_spam($str,$file))echothisisspam;elseechothisisnotspam;ab:3dog:3cat:2monkey:22随机颜色生成器functionrandomColor(){$str=#;for($i=0;$i6;$i++){$randNum=rand(0,15);switch($randNum){case10:$randNum=A;break;case11:$randNum=B;break;case12:$randNum=C;break;case13:$randNum=D;break;case14:$randNum=E;break;case15:$randNum=F;break;}$str.=$randNum;}return$str;}$color=randomColor();3从网上下载文件set_time_limit(0);//Supportsallfiletypes//URLHere:$url=治疗白癜风用什么药好拉萨最好的白癜风医院