php中设置session过期时间方法

<?php
if(!isset($_SESSION['last_access'])||(time()-$_SESSION['last_access'])>60)
 $_SESSION['last_access'] = time();
?>

<?php
unset($_SESSION['last_access']) 或 $_SESSION['last_access']='';
?>

session.gc_maxlifetime = 86400

#概率是gc_probability/gc_divisor
session.gc_probability = 1
session.gc_divisor = 100

<?
$str = " This line containstliberal rn use of whitespace.nn";

//去掉开始和结束的空白
$str = trim($str);

//去掉跟随别的挤在一块的空白
$str = preg_replace('/s(?=s)/', '', $str);

//最后，去掉非space 的空白，用一个空格代替
$str = preg_replace('/[nrt]/', ' ', $str);

echo "<pre>{$str}</pre>";

?>

$a=array("1"=>"ddf");
var_dump(empty($a));///boolean false
$b=0;
var_dump(empty($b));  ///boolean true

<?php
echo empty(strlen('be-evil.org'));

<?php

$length = strlen('be-evil.org');

echo empty($length);
?>

<?php
$stime=microtime();

$db=@mysql_connect("localhost","root","micronsky.net")   or die("数据库连接失入");
mysql_select_db("temp",$db);
//定义第一级分类
function mainfl()
{
     global $db;
$result=mysql_query("select id,fid,fname from wxjfl where fid=0   order by id desc",$db);
if ($myrow=mysql_fetch_array($result)) {
   do {
   echo $myrow["fname"];
   echo "<br>";
   echo subfl($myrow["id"],"　　");   //此处调用子级分类函数
   }
   while ($myrow=mysql_fetch_array($result));
}

}
//定义子级分类
function subfl($fid,$strdis)
{
global $db;
$result1=mysql_query("select id,fid,fname from wxjfl where fid=$fid   order by id desc",$db);
if ($myrow1=mysql_fetch_array($result1)) {
do {
   //echo $strdis;
   echo $strdis.$myrow1["fname"];
   echo "<br>";
   subfl($myrow1["id"],"　　".$strdis); //这里一定要注意并不需要像上面那个函数那样echo ...只要直接调用子级分类函数并付值就行了！同时这里也是递归部分
}
while ($myrow1=mysql_fetch_array($result1));
}
}

echo mainfl();

$ltime=microtime();
echo "<br>";
echo number_format($ltime-$stime,4);   //统计执行时间，这里就比ASP快多了，但这跟写法没多大关系，主要是PHP本身加入了加速器的原因！

?>

/**
 * 创建父节点树形数组
 * 参数
 * $ar 数组，邻接列表方式组织的数据
 * $id 数组中作为主键的下标或关联键名
 * $pid 数组中作为父键的下标或关联键名
 * 返回 多维数组
 **/
function find_parent($ar, $id='id', $pid='pid') {
  foreach($ar as $v) $t[$v[$id]] = $v;
  foreach ($t as $k => $item){
    if( $item[$pid] ){
      if( ! isset($t[$item[$pid]]['parent'][$item[$pid]]) )
         $t[$item[$id]]['parent'][$item[$pid]] =& $t[$item[$pid]];

          $t[$k]['reference'] = true;
    }
  }
  return $t;
}

/**
 * 创建子节点树形数组
 * 参数
 * $ar 数组，邻接列表方式组织的数据
 * $id 数组中作为主键的下标或关联键名
 * $pid 数组中作为父键的下标或关联键名
 * 返回 多维数组
 **/
function find_child($ar, $id='id', $pid='pid') {
  foreach($ar as $v) $t[$v[$id]] = $v;
  foreach ($t as $k => $item){
    if( $item[$pid] ) {
      $t[$item[$pid]]['child'][$item[$id]] =& $t[$k];

      $t[$k]['reference'] = true;
    }
  }
  return $t;
}

        foreach ($p as $key => $item) {
            if($item['reference']) continue;
            print_r($item);
        }

        foreach ($c as $key => $item) {
            if($item['reference']) continue;
            print_r($item);
        }

$mylist = array(array( 'parent_id'=>0,'id'=>1),
                    array( 'parent_id'=>0,'id'=>2),
                    array( 'parent_id'=>0,'id'=>3),   
                    array( 'parent_id'=>2,'id'=>4),
                    array( 'parent_id'=>2,'id'=>5),
                    array( 'parent_id'=>3,'id'=>6),
                    array( 'parent_id'=>3,'id'=>7),   
                    array( 'parent_id'=>4,'id'=>8),
                    array( 'parent_id'=>5,'id'=>9),
                    array( 'parent_id'=>5,'id'=>10)
                );

    function _findChildren($list, $p_id){    //数据层级化，
          $r = array();
          foreach($list as $id=>$item){
            if($item['parent_id'] == $p_id) {
                   $length = count($r);
                  $r[$length] = $item;
                  if($t = $this->_findChildren($list, $item['id']) ){
                      $r[$length]['children'] = $t;
                  }               
            }
          }
          return $r;
    } 
 

print_r(_findChildren($mylist, 0));

class db {
 private $host;
 private $user;
 private $pwd;
 private $dbname;
 private $Mysqli;
 function __construct($host, $user, $pwd, $dbname) {
  $this->host = $host;
  $this->user = $user;
  $this->pwd = $pwd;
  $this->dbname = $dbname;
  $this->db();
 }
 function db() {
  $this->mysqli = new mysqli ( $this->host, $this->user, $this->pwd, $this->dbname );
 }
 function select() {
  $this->mysqli->query("SET CHARSET GBK");
  $sql = "SELECT id,cname FROM hdw_channel";
  $result = $this->mysqli
   ->query ( $sql );
  $rows = array ();
  while ( $row = $result->fetch_assoc () ) {
   $rows [] = $row;
  }
  ECHO "<PRE>";
  print_r ( $rows );
 }
 function __wakeup(){   //反序列化，
  $this->db();
 }
}
$chanel = new db("localhost",'root','','hdcms');
//$chanel->select();
session_start();
$_SESSION['channel_obj'] = serialize($chanel);   //将对象序列化，保存的是对象的属性，没有方法，所以要用__wakeup()

class ren{
 private $name;
 private $age;
 function __construct($name,$age){
  $this->name =$name;
  $this->age = $age;
 }
 function show(){
  echo "姓名是：{$this->name}  年龄是：{$this->age}";
 }
 function __sleep(){
  return array_keys(get_object_vars($this));  //或得数组里边的键名，序列化某些变量
 }
}
$zao = new ren("赵六",44);
echo serialize($zao);       //序列化（指定哪个变量序列化）

====================================
 
session_start();
include '59.php';
$channel_obj=unserialize($_SESSION['channel_obj']);  //反序列化类对象
$channel_obj->select();  //有了__wakeup方法才可以起作用

<?php
/**************************************************************
 *
 * 使用特定function对数组中所有元素做处理
 * @param string &$array  要处理的字符串
 * @param string $function 要执行的函数
 * @return boolean $apply_to_keys_also  是否也应用到key上
 * @access public
 *
 *************************************************************/
function arrayRecursive(&$array, $function, $apply_to_keys_also = false)
{
    static $recursive_counter = 0;
    if (++$recursive_counter > 1000) {
        die('possible deep recursion attack');
    }
    foreach ($array as $key => $value) {
        if (is_array($value)) {
            arrayRecursive($array[$key], $function, $apply_to_keys_also);
        } else {
            $array[$key] = $function($value);
        }
 
        if ($apply_to_keys_also && is_string($key)) {
            $new_key = $function($key);
            if ($new_key != $key) {
                $array[$new_key] = $array[$key];
                unset($array[$key]);
            }
        }
    }
    $recursive_counter--;
}
 
/**************************************************************
 *
 * 将数组转换为JSON字符串（兼容中文）
 * @param array $array  要转换的数组
 * @return string  转换得到的json字符串
 * @access public
 *
 *************************************************************/
function JSON($array) {
 arrayRecursive($array, 'urlencode', true);
 $json = json_encode($array);
 return urldecode($json);
}

$array = array
       (
          'Name'=>'希亚',
          'Age'=>20
       );

echo JSON($array);
?>