php 检测是否为utf-8还是gb2312编码

function is_utf8($str)
{
$c=0; $b=0;
$bits=0;
$len=strlen($str);
for($i=0; $i<$len; $i++){
$c=ord($str[$i]);
if($c > 128){
if(($c >= 254)) return false;
elseif($c >= 252) $bits=6;
elseif($c >= 248) $bits=5;
elseif($c >= 240) $bits=4;
elseif($c >= 224) $bits=3;
elseif($c >= 192) $bits=2;
else return false;
if(($i+$bits) > $len) return false;
while($bits > 1){
$i++;
$b=ord($str[$i]);
if($b < 128 || $b > 191) return false;
$bits--;
}
}
}
return true;
}

function mb_is_utf8($string)  
{  
    return mb_detect_encoding()($string, 'UTF-8') === 'UTF-8';//新发现  
} 

function preg_is_utf8($string)  
{  
    return preg_match('/^.*$/u', $string) > 0;//preg_match('/^./u', $string)  
} 

<?php
$a = 'abc';
$b = 'a';
echo $$b; // 印出 abc
?>

<?php
define('PKEY1', 'abc');
define('PKEY2', 'def');
$i = 1;
$a = 'PKEY';
echo constant($a . $i); // abc
echo constant($a . ++$i); // def
?>

<?php
    echo 'http://'.$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
?>

<?php
function getServerIp(){ //用ifconfig读取服务器IP并输出为数组
  $ss = exec('/sbin/ifconfig | sed -n 's/^ *.*addr:\([0-9.]\{7,\}\) .*$/\1/p'',$arr);
  return $arr;
  }
$ips=getServerIp();
 
foreach($ips as $k=>$v){//过滤IP
 if(substr($v,0,3)=='127' || substr($v,0,3)=='10.' || substr($v,0,7)=='192.168' || substr($v,0,6)=='172.16'){
  unset($ips[$k]);
 }
}
shuffle($ips);//重新排序
print_r($ips);
?>

<?php
function GetIP(){
if(!empty($_SERVER["HTTP_CLIENT_IP"])){
  $cip = $_SERVER["HTTP_CLIENT_IP"];
}
elseif(!empty($_SERVER["HTTP_X_FORWARDED_FOR"])){
  $cip = $_SERVER["HTTP_X_FORWARDED_FOR"];
}
elseif(!empty($_SERVER["REMOTE_ADDR"])){
  $cip = $_SERVER["REMOTE_ADDR"];
}
else{
  $cip = "无法获取！";
}
return $cip;
}
echo GetIP();
?>

setcookie('mycookie','value');
//函数原型:int setcookie(string name,string value,int expire,string path,string domain,int secure)
echo($mycookie);
echo($HTTP_COOKIE_VARS['mycookie']);
echo($_COOKIE['mycookie']);

<?php setcookie('name'); ?>

setcookie('mycookie');或setcookie('mycookie','');或setcookie("mycookie",false);
//setcookie('mycookie','',time()-3600);
echo($HTTP_COOKIE_VARS['mycookie']);
print_r($_COOKIE);

setcookie('mycookie','',time()-3600);

$expire = time() + 86400; // 设置24小时的有效期
setcookie ("var_name", "var_value", $expire); // 设置一个名字为var_name的cookie，并制定了有效期
setcookie ("var_name_expire", $expire, $expire); // 再将过期时间设置进cookie以便你能够知道var_name的过期时间

//--------设置COOKIE，1小时后过期------//
setcookie('TestCookie','hello word 秦迷',time()+3600);
//setrawcookie不进行URL编码
header('Content-type: text/html');
 

//查看发送的报头
var_dump(headers_list());#array(2) { [0]=> string(85) "Set-Cookie: TestCookie=hello+word+%C7%D8%C3%D4; expires=Tue, 19-Apr-2011 10:06:14 GMT" [1]=> string(23) "Content-type: text/html" }
echo '<br>';
echo $_COOKIE['TestCookie'];#hello word 秦迷
//兼容旧版本(淘汰)
if(isset($HTTP_COOKIE_VARS["TestCookie"])){
    echo $HTTP_COOKIE_VARS["TestCookie"];
}
 

echo '<br>';
//输出所有 cookie
print_r($_COOKIE);#Array ( [key] => value [TestCookie] => hello word 秦迷 )
?>
 

<script type="text/javascript">
<!--
alert(document.cookie);
//-->
</script>
 

<?php
//-----设置数组COOKIE-------//
setcookie("cookie[one]","oneVal",time()+3600);
setcookie("cookie[two]","twoVal",time()+3600);
 

echo '<br>';
echo $_COOKIE['cookie']['two'];#twoVal
echo '<br>';
 

//输出 cookie （在重载页面后）
if (isset($_COOKIE["cookie"]))
{
    foreach ($_COOKIE["cookie"] as $name => $value)
    {
       echo "$name : $value <br>";
       /**
        * two : twoVal
        * one : oneVal
        */
 

    }
}
 

//设置过期，删除COOKIE
//setcookie('TestCookie', '', time() - 3600);
//setcookie('cookie[one]', '', time() - 3600);