PHP自定义函数获取URL中一级域名的方法

本文实例讲述了PHP自定义函数获取URL中一级域名的方法。分享给大家供大家参考，具体如下：

<?php/* * Created on 2016-8-23 */function regular_domain（$domain）{if （substr （ $domain, 0, 7 ） == "http://"） {$domain = substr （ $domain, 7 ）;}if （strpos （ $domain, "/" ） ！== false） {$domain = substr （ $domain, 0, strpos （ $domain, "/" ） ）;}return strtolower （ $domain ）;}function top_domain（$domain） {$domain = regular_domain （ $domain ）;$iana_root = array （"ac","ad","ae","aero","af","ag","ai","al","am","an","ao","aq","ar","arpa","as","asia","at","au","aw","ax","az","ba","bb","bd","be","bf","bg","bh","bi","biz","bj","bl","bm","bn","bo","bq","br","bs","bt","bv","bw","by","bz","ca","cat","cc","cd","cf","cg","ch","ci","ck","cl","cm","cn","co","com","coop","cr","cu","cv","cw","cx","cy","cz","de","dj","dk","dm","do","dz","ec","edu","ee","eg","eh","er","es","et","eu","fi","fj","fk","fm","fo","fr","ga","gb","gd","ge","gf","gg","gh","gi","gl","gm","gn","gov","gp","gq","gr","gs","gt","gu","gw","gy","hk","hm","hn","hr","ht","hu","id","ie","il","im","in","info","int","io","iq","ir","is","it","je","jm","jo","jobs","jp","ke","kg","kh","ki","km","kn","kp","kr","kw","ky","kz","la","lb","lc","li","lk","lr","ls","lt","lu","lv","ly","ma","mc","md","me","mf","mg","mh","mil","mk","ml","mm","mn","mo","mobi","mp","mq","mr","ms","mt","mu","museum","mv","mw","mx","my","mz","na","name","nc","ne","net","nf","ng","ni","nl","no","np","nr","nu","nz","om","org","pa","pe","pf","pg","ph","pk","pl","pm","pn","pr","pro","ps","pt","pw","py","qa","re","ro","rs","ru","rw","sa","sb","sc","sd","se","sg","sh","si","sj","sk","sl","sm","sn","so","sr","ss","st","su","sv","sx","sy","sz","tc","td","tel","tf","tg","th","tj","tk","tl","tm","tn","to","tp","tr","travel","tt","tv","tw","tz","ua","ug","uk","um","us","uy","uz","va","vc","ve","vg","vi","vn","vu","wf","ws","xxx","ye","yt","za","zm","zw"）;$sub_domain = explode （ ".", $domain ）;$top_domain = "";$top_domain_count = 0;for（$i = count （ $sub_domain ） - 1; $i >= 0; $i --） {if （$i == 0） {// just in case of something like NAME.COMbreak;}if （in_array （ $sub_domain [$i], $iana_root ）） {$top_domain_count ++;$top_domain = "." . $sub_domain [$i] . $top_domain;if （$top_domain_count >= 2） {break;}}}$top_domain = $sub_domain [count （ $sub_domain ） - $top_domain_count - 1] . $top_domain;return $top_domain;}echo top_domain（"http://tools.jb51.net/"）;?>

运行结果为：

更多关于PHP相关内容感兴趣的读者可查看本站专题：《php正则表达式用法总结》、《php curl用法总结》、《PHP数组（Array）操作技巧大全》、《php排序算法总结》、《PHP常用遍历算法与技巧总结》、《PHP数据结构与算法教程》、《php程序设计算法总结》、《PHP数学运算技巧总结》、《PHP运算与运算符用法总结》、《php字符串（string）用法总结》及《php常见数据库操作技巧汇总》
希望本文所述对大家PHP程序设计有所帮助。