一些常用的PHP函数(整理)
/** * 邹颢 * [email protected] *//** * 获取当前毫秒 * @return string */function get_millisecond() { $t = explode ( " ", microtime () ); $t = $t [1] . ($t [0] * 1000); $t2 = explode ( ".", $t ); return $t2 [0];}/** * curl模拟http/https post请求 * @param string $url 请求网址 * @param array $data 请求参数 * @return string 网址内容 */function curl_post($url,$data=array()){ $ch = curl_init($url); curl_setopt($ch, CURLOPT_RETURNTRANSFER,true) ; // 获取数据返回 curl_setopt($ch, CURLOPT_POST,true) ; // 启用时会发送一个常规的POST请求,类型为:application/x-www-form-urlencoded,就像表单提交的一样。 curl_setopt($ch, CURLOPT_POSTFIELDS,$data); // 在HTTP中的“POST”操作。如果要传送一个文件,[email protected] if(substr($url,0,5)=='https'){ curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); } $content=curl_exec($ch); curl_close($ch) ; return $content;}/** * curl模拟http get请求 * @param string $url 请求网址 * @param string|array $data 请求参数 * @return string 网址内容 */function curl_get($url,$data=array()){ $url=rtrim($url,'/'); if(!empty($data)){ if(is_array($data)){ $first=true; foreach($data as $k=>$v){ if($first){ $url.='?'; $first=false; }else{ $url.='&'; } $url.="{$k}={$v}"; } }else{ $data=ltrim('?',$data); $url.='?'.$data; } } $ch = curl_init($url); curl_setopt($ch,CURLOPT_HEADER,false); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true) ; // 获取数据返回 if(substr($url,0,5)=='https'){ curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); } $content = curl_exec($ch); curl_close($ch); return $content;}/** * 二维数组按键值排序 * @param array $arr 二维数组 * @param string $keys 键值 * @param string $type 升序:asc,降序:desc(else) * @return array */function array_sort($arr,$keys,$type='asc'){ $keysvalue = $new_array = array(); foreach ($arr as $k=>$v){ $keysvalue[$k] = $v[$keys]; } if($type == 'asc'){ asort($keysvalue); }else{ arsort($keysvalue); } reset($keysvalue); foreach ($keysvalue as $k=>$v){ $new_array[$k] = $arr[$k]; } return $new_array;}/** * 获取客户端ip * @param number $type * @return string */function get_client_ip($type = 0) { $type = $type ? 1 : 0; static $ip = NULL; if ($ip !== NULL) return $ip[$type]; if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) { $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']); $pos = array_search('unknown',$arr); if(false !== $pos) unset($arr[$pos]); $ip = trim($arr[0]); }elseif (isset($_SERVER['HTTP_CLIENT_IP'])) { $ip = $_SERVER['HTTP_CLIENT_IP']; }elseif (isset($_SERVER['REMOTE_ADDR'])) { $ip = $_SERVER['REMOTE_ADDR']; } // IP地址合法验证 $long = sprintf("%u",ip2long($ip)); $ip = $long ? array($ip, $long) : array('0.0.0.0', 0); return $ip[$type];}/** * 将字符串转换为驼峰式命名 * * @param string $str * @param boolean $big * true大驼峰式 false小驼峰式 * @return string */function hump_type($str, $big = false) { $str = strtolower ( $str ); $big and ucfirst ( $str ); $str = preg_replace ( "/_([a-zA-Z])/e", "strtoupper('\\1')", $str ); return $str;}/** * 遍历删除文件夹 * * @param string $path * 文件夹地址 * @return boolean */function delete_files($path) { if (is_file ( $path )) { return unlink ( $path ); } if (is_dir ( $path )) { $handle = opendir ( $path ); if ($handle != false) { while ( false !== ($file = readdir ( $handle )) ) { if (in_array ( $file, array ( '.', '..' ) )) continue; $file = $path . '/' . $file; if (is_dir ( $file )) { delete_files ( $file ); } else if (is_file ( $file )) { if (unlink ( $file ) == false) return false; } } closedir ( $handle ); } return true; }}/** * 截取字符串(可截取utf8的) * * @param string $str * @param int $start * @param int $length * @param string $trim * @param string $charset * @return string */function sub($str, $start, $length, $trim = "...", $charset = 'UTF-8') { $length+=2; if (function_exists ( 'mb_get_info' )) { $iLength = mb_strlen ( $str, $charset ); $str = mb_substr ( $str, $start, $length, $charset ); if($length\n(\s+)/m', '] => ', $output ); $output = '<pre class="brush:php;toolbar:false">' . htmlspecialchars ( $output, ENT_QUOTES ) . ''; } echo ($output);}/** * 从左边查询子串,找到则删除子串,只删除一次 * * @param string $str * @param string $find * @return string */function substr_left_once($str, $find) { $start = strpos ( $str, $find ); if (is_bool ( $start )) { return $str; } else { return substr ( $str, $start + strlen ( $find ), strlen ( $str ) ); }}/** * 从右边查询子串,找到则删除子串,只删除一次 * * @param string $str * @param string $find * @return string */function substr_right_once($str, $find) { $end = strrpos ( $str, $find ); if (is_bool ( $end )) { return $str; } else { return substr ( $str, 0, $end ); }}

Thedifferencebetweenunset()andsession_destroy()isthatunset()clearsspecificsessionvariableswhilekeepingthesessionactive,whereassession_destroy()terminatestheentiresession.1)Useunset()toremovespecificsessionvariableswithoutaffectingthesession'soveralls

Stickysessionsensureuserrequestsareroutedtothesameserverforsessiondataconsistency.1)SessionIdentificationassignsuserstoserversusingcookiesorURLmodifications.2)ConsistentRoutingdirectssubsequentrequeststothesameserver.3)LoadBalancingdistributesnewuser

PHPoffersvarioussessionsavehandlers:1)Files:Default,simplebutmaybottleneckonhigh-trafficsites.2)Memcached:High-performance,idealforspeed-criticalapplications.3)Redis:SimilartoMemcached,withaddedpersistence.4)Databases:Offerscontrol,usefulforintegrati

Session in PHP is a mechanism for saving user data on the server side to maintain state between multiple requests. Specifically, 1) the session is started by the session_start() function, and data is stored and read through the $_SESSION super global array; 2) the session data is stored in the server's temporary files by default, but can be optimized through database or memory storage; 3) the session can be used to realize user login status tracking and shopping cart management functions; 4) Pay attention to the secure transmission and performance optimization of the session to ensure the security and efficiency of the application.

PHPsessionsstartwithsession_start(),whichgeneratesauniqueIDandcreatesaserverfile;theypersistacrossrequestsandcanbemanuallyendedwithsession_destroy().1)Sessionsbeginwhensession_start()iscalled,creatingauniqueIDandserverfile.2)Theycontinueasdataisloade

Absolute session timeout starts at the time of session creation, while an idle session timeout starts at the time of user's no operation. Absolute session timeout is suitable for scenarios where strict control of the session life cycle is required, such as financial applications; idle session timeout is suitable for applications that want users to keep their session active for a long time, such as social media.

The server session failure can be solved through the following steps: 1. Check the server configuration to ensure that the session is set correctly. 2. Verify client cookies, confirm that the browser supports it and send it correctly. 3. Check session storage services, such as Redis, to ensure that they are running normally. 4. Review the application code to ensure the correct session logic. Through these steps, conversation problems can be effectively diagnosed and repaired and user experience can be improved.

session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.


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