php实现IP地址转换为整型数字实例

 function ip2number($ip)
      {

          $t = explode('.', $ip);
          $x = 0;
          for ($i = 0; $i < 4; $i++)

          {
              $x = $x * 256 + $t[$i];

          }
          return $x;

      }

function number2ip($num)

      {
          $t = $num;
          $a = array();

          for ($i = 0; $i < 4; $i++)
          {
              $x = $t % 256;
              if($x < 0) $x += 256;
              array_unshift($a, $x);
              $t = intval($t / 256);
          }
          return implode('.', $a);
 }

$header = get_headers($url, 1);
if (strpos($header[0], ’301′) || strpos($header[0], ’302′)) {
if (is_array($header['Location'])) {
return $header['Location'][count($header['Location'])-1];
} else {
return $header['Location'];
}
} else {
return $url;
}

<?php
//
echo get_redirect_url('http://www.111cN.nEt');
//输出结果为：http://code.google.com/android/
function get_redirect_url($url){
    $redirect_url = null;

    $url_parts = @parse_url($url);
    if (!$url_parts) return false;
    if (!isset($url_parts['host'])) return false; //can't process relative URLs
    if (!isset($url_parts['path'])) $url_parts['path'] = '/';

    $sock = fsockopen($url_parts['host'], (isset($url_parts['port']) ? (int)$url_parts['port'] : 80), $errno, $errstr, 30);
    if (!$sock) return false;

    $request = "HEAD " . $url_parts['path'] . (isset($url_parts['query']) ? '?'.$url_parts['query'] : '') . " HTTP/1.1rn";
    $request .= 'Host: ' . $url_parts['host'] . "rn";
    $request .= "Connection: Closernrn";
    fwrite($sock, $request);
    $response = '';
    while(!feof($sock)) $response .= fread($sock, 8192);
    fclose($sock);

    if (preg_match('/^Location: (.+?)$/m', $response, $matches)){
        if ( substr($matches[1], 0, 1) == "/" )
            return $url_parts['scheme'] . "://" . $url_parts['host'] . trim($matches[1]);
        else
            return trim($matches[1]);

    } else {
        return false;
    }

}

<?php
$str = "asd啊<b>是</b>大叔大叔asd杀毒发[NextPage]生的啊师傅 <a href="asd">asd</a> 啊师傅asd a速度发啥地方";
//接收页码(如果不存在就为1)
$page = $_REQUEST['page'] ? $_REQUEST['page'] : 1;
//通过分割符分割内容
$arr = explode("[NextPage]",$str);
//如果分割出来的数组大小为1即未进行分页
if(count($arr)==1){
 echo $str;
}else{
 //按页码输出相应的内容
 echo $arr[$page-1];
 //分页页码
 for($i=1;$i<=count($arr);$i++){ 
  if($page == $i){//当前页
   echo "<a href='?page=".$i."' class='current'>".$i."</a> ";
  }else{
    echo "<a href='?page=".$i."' >".$i."</a> ";
  }
 }
}
?>

<?php
echo memory_get_usage(), '<br />';  // 79248
$tmp = str_repeat('http://3aj.cn/', 4000);  // 135408
echo memory_get_usage(), '<br />';
unset($tmp);
echo memory_get_usage();  // 79248
?> 

<?php  

 function convert($size){  

    $unit=array('b','kb','mb','gb','tb','pb'); 

     return @round($size/pow(1024,($i=floor(log($size,1024)))),2).' '.$unit[$i]; 

 } 

echo convert(memory_get_usage(true)); 

 ?>

<?php 
//memory_get_usage(); 
 
$m1 = memory_get_usage(); 
echo '<br /> m1:',$m1;  // m1:80160
 
$a = 'hello'; 
$b =  str_repeat($a,1000); 
 
$m2 = memory_get_usage(); 
echo '<br /> m2:',$m2;  // m2:85624

unset($b); 
 
$m3 = memory_get_usage(); 
echo '<br /> m3:',$m3;  // m3:80600
?>