php检查验证IP为有效IP地址函数

 
if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE)) {// it's valid
}else {// it's not valid
}

if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {// it's valid
}else {// it's not valid
}

//判断IP格式
 function is_ip($gonten){
        $ip = explode(".",$gonten);
        for($i=0;$i<count($ip);$i++)
       {
              if($ip[$i]>255){
               return (0);
               }
        }
        return ereg("^[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}$",$gonten);
}

<?php
echo(mt_rand());
echo(mt_rand());
echo(mt_rand(10,100));
?>
输出类似：

3150906288
513289678
35

function roll () {
　　return mt_rand(1,6);
　　}

echo roll();

function roll ($sides) {
　　return mt_rand(1,$sides);

}
　　echo roll(6); // roll a six-sided die
　　echo roll(10); // roll a ten-sided die
　　echo roll(20); // roll a twenty-sided die

<?php
function genRandomString($len) {
    $chars = array(
        "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k",
        "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
        "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G",
        "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R",
        "S", "T", "U", "V", "W", "X", "Y", "Z", "0", "1", "2",
        "3", "4", "5", "6", "7", "8", "9"
    );

    $charsLen = count($chars) - 1;

    shuffle($chars); // 将数组打乱
   
    $output = "";
    for ($i=0; $i<$len; $i++) {
        $output .= $chars[mt_rand(0, $charsLen)];
    }
   
    return $output;
}

$str = genRandomString(25);
$str .= "<br />";
$str .= genRandomString(25);
$str .= "<br />";
$str .= genRandomString(25);
$str .= "<br /><br />";

echo $str;
?>

程序输出如下：

DmLVAmDkEJz8wHXRCNwzvANlB
BILZSA19YyuSVcR17KrrZsOKO
inlWlQF0GSabN3l589y9s16Gg

/**
  +----------------------------------------------------------
 * 生成随机字符串
  +----------------------------------------------------------
 * @param int       $length  要生成的随机字符串长度
 * @param string    $type    随机码类型：0，数字+大写字母；1，数字；2，小写字母；3，大写字母；4，特殊字符；-1，数字+大小写字母+特殊字符
  +----------------------------------------------------------
 * @return string
  +----------------------------------------------------------
 */
function randCode($length = 5, $type = 0) {
    $arr = array(1 => "0123456789", 2 => "abcdefghijklmnopqrstuvwxyz", 3 => "ABCDEFGHIJKLMNOPQRSTUVWXYZ", 4 => "~@#$%^&*(){}[]|");
    if ($type == 0) {
        array_pop($arr);
        $string = implode(",", $arr);
    } else if ($type == "-1") {
        $string = implode(",", $arr);
    } else {
        $string = $arr[$type];
    }
    $count = strlen($string) - 1;
    for ($i = 0; $i < $length; $i++) {
        $str[$i] = $string[rand(0, $count)];
        $code .= $str[$i];
    }
    return $code;
}

function make_password( $length = 8 )
{
    // 密码字符集，可任意添加你需要的字符
    $chars = array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
    'i', 'j', 'k', 'l','m', 'n', 'o', 'p', 'q', 'r', 's',
    't', 'u', 'v', 'w', 'x', 'y','z', 'A', 'B', 'C', 'D',
    'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L','M', 'N', 'O',
    'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y','Z',
    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '!',
    '@','#', '$', '%', '^', '&', '*', '(', ')', '-', '_',
    '[', ']', '{', '}', '<', '>', '~', '`', '+', '=', ',',
    '.', ';', ':', '/', '?', '|');

    // 在 $chars 中随机取 $length 个数组元素键名
    $keys = array_rand($chars, $length);

    $password = '';
    for($i = 0; $i < $length; $i++)
    {
        // 将 $length 个数组元素连接成字符串
        $password .= $chars[$keys[$i]];
    }

    return $password;
}

$arr = array(…………) ;// 假设有数组包含一万个元素，里面有重复的元素。

 
$arr = array_flip(array_flip($arr)); // 这样便可以删除重复元素。

 
$arr1 = array("age" => 30, "name" => '快乐园');

 
$arr2 = array_flip($arr1);　// $arr2 就是 array(30 => "age", '快乐园' => "name");

 
$arr1 = array("age" => 30, "name" => '快乐园', "age" => 20);　"age" => 2 0将会取代 "age" => 30

 
$arr1 = array("name" => '快乐园', "age" => 45);

$arr1 = array("age" => 30, "name" => '快乐园', "age" => 20);

 
$arr1 = array_flip($arr1); // $arr1 变成了 array("快乐园" => "name", 20 => "age");

 
// 再把 $arr1 的键名与值还复：

 
$arr1 = array_flip($arr1);

$output = array(1, 2, 2, 'www.111cn.net', 5, 4, 4, 4, 2, 7, 5, 9, 10);
delsame($output);
while(list($key, $value) = each($output))
{
echo "$key:$value"."<br>";
}
//方法二

function uniquearray($array)

{

// get unique elts as keys in assoc. array

for ($i=0,$n=count($array, 1);$i<$n;$i )

$u_array[$array[$i]] = 1;

// copy keys only into another array

reset($u_array, 1);

for ($i=0,$n=count($u_array, 1);$i<$n;$i ) {

$unduplicated_array[] = key($u_array, 1);

next($u_array, 1);

}

return $unduplicated_array;

}

/*-----保存COOKIE-----*/
$url = 'www.111cn.net'; //url地址
$post = "id=user&pwd=123456"; //POST数据
$cookie = tempnam('./','cookie'); //cookie临时文件
$ch = curl_init($url); //初始化
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); //返回获取的输出文本流
curl_setopt($ch,CURLOPT_POSTFIELDS,$post); //发送POST数据
curl_setopt($ch,CURLOPT_COOKIEJAR,$cookie); //保存获得的cookie
curl_exec($ch); //执行curl
curl_close($ch); //关闭curl

/*-----使用COOKIE-----*/
curl_setopt($ch,CURLOPT_COOKIEFILE,$cookie);

/*-----保存COOKIE-----*/
$url = 'www.111cn.net'; //url地址
$post = "id=user&pwd=123456"; //POST数据
$cookie = tempnam('./','cookie'); //cookie临时文件
$ch = curl_init($url); //初始化
curl_setopt($ch,CURLOPT_HEADER,1); //将头文件的信息作为数据流输出
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); //返回获取的输出文本流
curl_setopt($ch,CURLOPT_POSTFIELDS,$post); //发送POST数据
$content = curl_exec($ch); //执行curl并赋值给$content
preg_match('/Set-Cookie:(.*);/iU',$content,$str); //正则匹配
$cookie = $str[1]; //获得COOKIE（SESSIONID）
curl_close($ch); //关闭curl

/*-----使用COOKIE-----*/
curl_setopt($ch,CURLOPT_COOKIE,$cookie);

/*-----保存COOKIE-----*/
$url = 'www.111cn.net'; //url地址
$post = "id=user&pwd=123456"; //POST数据
$cookie = tempnam('./','cookie'); //cookie临时文件
$ch = curl_init($url); //初始化
curl_setopt($ch,CURLOPT_HEADER,1); //将头文件的信息作为数据流输出
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); //返回获取的输出文本流
curl_setopt($ch,CURLOPT_POSTFIELDS,$post); //发送POST数据
$content = curl_exec($ch); //执行curl并赋值给$content
preg_match('/Set-Cookie:(.*);/iU',$content,$str); //正则匹配
$cookie = $str[1]; //获得COOKIE（SESSIONID）
curl_close($ch); //关闭curl

/*-----使用COOKIE-----*/
curl_setopt($ch,CURLOPT_COOKIE,$cookie);

$ch = curl_init ();
curl_setopt($ch, CURLOPT_URL, 'http://www.111cn.net');
curl_setopt($ch, CURLOPT_TIMEOUT, 200);
curl_setopt($ch, CURLOPT_HEADER, FALSE);
curl_setopt($ch, CURLOPT_NOBODY, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, FALSE);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');

curl_exec($ch);

$httpCode = curl_getinfo($ch,CURLINFO_HTTP_CODE);