实验吧——你真的会PHP吗？（intval范围 php中\00的利用）

 1 <?php
 2 
 3 
 4 $info = ""; 
 5 $req = [];
 6 $flag="xxxxxxxxxx";
 7 
 8 ini_set("display_error", false); 
 9 error_reporting(0); 
10 
11 
12 if(!isset($_POST[‘number‘])){
13    header("hint:6c525af4059b4fe7d8c33a.txt");
14 
15    die("have a fun!!"); 
16 }
17 
18 foreach([$_POST] as $global_var) { 
19     foreach($global_var as $key => $value) { 
20         $value = trim($value); 
21         is_string($value) && $req[$key] = addslashes($value); 
22     } 
23 } 
24 
25 
26 function is_palindrome_number($number) { 
27     $number = strval($number); 
28     $i = 0; 
29     $j = strlen($number) - 1; 
30     while($i < $j) { 
31         if($number[$i] !== $number[$j]) { 
32             return false; 
33         } 
34         $i++; 
35         $j--; 
36     } 
37     return true; 
38 } 
39 
40 
41 if(is_numeric($_REQUEST[‘number‘])){
42     
43    $info="sorry, you cann‘t input a number!";
44 
45 }elseif($req[‘number‘]!=strval(intval($req[‘number‘]))){
46       
47      $info = "number must be equal to it‘s integer!! ";  
48 
49 }else{
50 
51      $value1 = intval($req["number"]);
52      $value2 = intval(strrev($req["number"]));  
53 
54      if($value1!=$value2){
55           $info="no, this is not a palindrome number!";
56      }else{
57           
58           if(is_palindrome_number($req["number"])){
59               $info = "nice! {$value1} is a palindrome number!"; 
60           }else{
61              $info=$flag;
62           }
63      }
64 
65 }
66 
67 echo $info;