Question

谁能帮我看看下面这段PHP代码是什么意思啊？

<?php

if(!defined("IN_DISCUZ"))exit("Access Denied");
$content=ob_get_contents();
ob_end_clean();
$_G["gzipcompress"] ?ob_start("ob_gzhandler") : ob_start();
$content = str_replace(
array(
'fg3662','fg3799','fg8597','fg6661','fg7790','fg4093','fg9176','fg6499','fg6282','fg3840','fg2576',,'fg6370','fg1552','fg5337','fg3074','fg1653','fg2849','fg7720','fg1770','fg7701','fg1837','fg8100','fg2992','fg9310','fg5015','fg8064','fg9961','fg5915','fg2276','fg5547','fg9908','fg9722','fg7470','fg3630','fg6540','fg2521','fg7881','fg2832','fg3670','fg2069','fg3739','fg7940','fg8470','fg2386','fg9753','fg3071'),
array(
'ptm pbw hm','small_nav_bg','wall','small_nav','nav_right','umzliao','y','clear','header_por','logo_p','bA','sch_p','Ant3Search','bl','tx','p_submenu','sub-header','layout','sub-logo','sub-menu','menu-nav','nav-floor','sub-login','login_hou','f14 b s2','tBlogs','tQQ','tSina','p_con','p_daohang','bnav_L','bnav_channel','nob','bnav_R','managemenu_menu',cl','t_huodong','n_huodong','n_hd_gj','side','wgd','st','tWall_','tWallB','scrollBgTW','scrollTW','say','top_ann','top_ad','wp','life','coltitle','subnav','life_l','life_zbk','hot_tit foodico','life_cont','lfpic','lftext','life_zbk','hot_tit marrico','life_cont','lfpic','lftext','life_zbk bor-b','hot_tit houseico','life_cont','lfpic','lftext','life_r','tools_box','hd','bd','t1','t2','tools_box mbm','hd','bd','t3','t4','t5','lfside_ad','info','fish_content','jx09-tab','i_content','wp','lfsub','k0_l','border','subtitle','con','k0_c','border','subtitle','con','k0_r','border','subtitle','con','buy','coltitle','subnav','buy_l','buy_zbk','hot_tit foodico','life_cont','lfpic','buytext','life_zbk','hot_tit buyico','life_cont','life_zbk bor-b','hot_tit buyico','life_cont','buy_r','salecont','border','coltitle1','shjph','hdkj','coltitle','subnav','Left_F','Left_C_Tit1','Left_F_List1','Mid_F','hd_r','photo','photo_tit','roollscr','clikL','rollBox','clikR','Hezuo','Hezuo_tit text_r','Hezuo_Bott','bm cl','z xw1','z','layout clearall','main','main-mod share','main-hd link0','z confirm-btn','main-bd','z mt10','newflash','hot-news cl','newtjt','side','b_tr','b_tr1','haslogin_right','b_tr2','b_tj','b_tr2n','tg_active','div_main_content w268 pb10','mrht','tab_div mt14', cl','pcb','bbda cl mtw mbm pbm','pstl xs1','fgoo_pfbm','fgoo_pfbmlf','fgoo_pfbmrt','km_icon thread_add_foot','pi','fgoo_jico','p_pop blk bui','m z','fgoo_yhzico','fgoo_show','atten_btn','fgoo_level','fgoo_gray','fgoo_anniu','register-intro','ptg','fgoo_bltx','ocn_fghot','list','fgoo_vadx','f_pst','pbt cl','upfl','ptm pnpost','linknav','y','contents','contents_left','cl_part','clp1_left','clp1_right','cl_part','cl_part','listname','items','cl_part','julebumulu','kaifangpingtai','contents_right','tb_aspect','wp mtn mbm'),
$content);
echo $content;
;echo ' '
?>

Answer 1

if(!defined("IN_DISCUZ"))exit("Access Denied");
/** 如果没有定义IN_DISCUZ常量则不允许执行下面的代码，直接
拒绝访问。
目的是做访问控制。
也就是说用户直接在WEB上直接访问这个PHP文件是不允许的，
需要通过DISCUZ的一个公共文件引入后再访问
（该公共文件做权限管理和输入的GET/POST数据的过滤）
*/
$content=ob_get_contents();
ob_end_clean();
$_G["gzipcompress"] ?ob_start("ob_gzhandler") : ob_start();
//之后生成的内容先放入内存缓冲区
//清空缓冲区
$content = str_replace(
array(
'fg3662','fg3799','fg8597','fg6661','fg7790','fg4093','fg9176','fg6499','fg6282','fg3840','fg2576',,'fg6370','fg1552','fg5337','fg3074','fg1653','fg2849','fg7720','fg1770','fg7701','fg1837','fg8100','fg2992','fg9310','fg5015','fg8064','fg9961','fg5915','fg2276','fg5547','fg9908','fg9722','fg7470','fg3630','fg6540','fg2521','fg7881','fg2832','fg3670','fg2069','fg3739','fg7940','fg8470','fg2386','fg9753','fg3071'),
array(
'ptm pbw hm','small_nav_bg','wall','small_nav','nav_right','umzliao','y','clear','header_por','logo_p','bA','sch_p','Ant3Search','bl','tx','p_submenu','sub-header','layout','sub-logo','sub-menu','menu-nav','nav-floor','sub-login','login_hou','f14 b s2','tBlogs','tQQ','tSina','p_con','p_daohang','bnav_L','bnav_channel','nob','bnav_R','managemenu_menu',cl','t_huodong','n_huodong','n_hd_gj','side','wgd','st','tWall_','tWallB','scrollBgTW','scrollTW','say','top_ann','top_ad','wp','life','coltitle','subnav','life_l','life_zbk','hot_tit foodico','life_cont','lfpic','lftext','life_zbk','hot_tit marrico','life_cont','lfpic','lftext','life_zbk bor-b','hot_tit houseico','life_cont','lfpic','lftext','life_r','tools_box','hd','bd','t1','t2','tools_box mbm','hd','bd','t3','t4','t5','lfside_ad','info','fish_content','jx09-tab','i_content','wp','lfsub','k0_l','border','subtitle','con','k0_c','border','subtitle','con','k0_r','border','subtitle','con','buy','coltitle','subnav','buy_l','buy_zbk','hot_tit foodico','life_cont','lfpic','buytext','life_zbk','hot_tit buyico','life_cont','life_zbk bor-b','hot_tit buyico','life_cont','buy_r','salecont','border','coltitle1','shjph','hdkj','coltitle','subnav','Left_F','Left_C_Tit1','Left_F_List1','Mid_F','hd_r','photo','photo_tit','roollscr','clikL','rollBox','clikR','Hezuo','Hezuo_tit text_r','Hezuo_Bott','bm cl','z xw1','z','layout clearall','main','main-mod share','main-hd link0','z confirm-btn','main-bd','z mt10','newflash','hot-news cl','newtjt','side','b_tr','b_tr1','haslogin_right','b_tr2','b_tj','b_tr2n','tg_active','div_main_content w268 pb10','mrht','tab_div mt14', cl','pcb','bbda cl mtw mbm pbm','pstl xs1','fgoo_pfbm','fgoo_pfbmlf','fgoo_pfbmrt','km_icon thread_add_foot','pi','fgoo_jico','p_pop blk bui','m z','fgoo_yhzico','fgoo_show','atten_btn','fgoo_level','fgoo_gray','fgoo_anniu','register-intro','ptg','fgoo_bltx','ocn_fghot','list','fgoo_vadx','f_pst','pbt cl','upfl','ptm pnpost','linknav','y','contents','contents_left','cl_part','clp1_left','clp1_right','cl_part','cl_part','listname','items','cl_part','julebumulu','kaifangpingtai','contents_right','tb_aspect','wp mtn mbm'),
$content);

//把fg2386之类的东西转换为ptm pbw hm之类的东西（这些应该是CSS的样式名称，也就是fg2386为缩写的样式名，ptm pbw hm为实际生成的样式名称）

echo $content;
;echo ' '
//输出之

Answer 2

整体的意思是把数组里的内容替换成一些固定的标签(就是里面一个个单词)，然后输出。
if(!defined("IN_DISCUZ"))exit("Access Denied"); // 这个不用解释了吧

$content=ob_get_contents(); // 通过一个方法获取一个结果，看样子是字符串

ob_end_clean(); //这个函数得看它自己的使用

$_G["gzipcompress"] ?ob_start("ob_gzhandler") : ob_start(); //判断$_G["gzipcompress"] 以决定执行ob_start("ob_gzhandler") 还是ob_start()

$content = str_replace(... // 开始替换

echo $content; //输出

;echo ' ' //输出

Answer 3

把数组里的内容替换成一些固定的标签(就是里面一个个单词)，然后输出。