Easy to understand PHP anti injection code

First, save the following code as safe.php in the root of the site, and then include(" /safe.php ") before each PHP file. You can:

PHP anti-injection code method 1:

 
<?php 
//Illegal characters to filter
$ArrFiltrate=array( "'" , " ; " , " union " ); 
//Error to jump to the url, do not fill the default previous page
$StrGoUrl= "" ; 
//Whether there are values in the array
function FunStringExist($StrFiltrate,$ArrFiltrate){ 
foreach ($ArrFiltrate as $key=>$value){ 
if (eregi($value,$StrFiltrate)){ 
return true; 
} 
} 
return false; 
} 
//Merge $_POST and $_GET
if(function_exists(array_merge)){ 
$ArrPostAndGet=array_merge($HTTP_POST_VARS,$HTTP_GET_VARS); 
}else{ 
foreach($HTTP_POST_VARS as $key=>$value){ 
$ArrPostAndGet[]=$value; 
} 
foreach($HTTP_GET_VARS as $key=>$value){ 
$ArrPostAndGet[]=$value; 
} 
} 
//Verify the start
foreach($ArrPostAndGet as $key=>$value){ 
if (FunStringExist($value,$ArrFiltrate)){ 
echo  " <script language= " javascript " >alert( "Illegal character" );</script> " ; 
if (emptyempty($StrGoUrl)){ 
echo  " <script language= " javascript " >history.go(-1);</script> " ; 
}else{ 
echo  " <script language= " javascript " >window.location= "" .$StrGoUrl. "" ;</script> " ; 
} 
exit; 
} 
} 
?> 

PHP anti-injection code method 2:

 
 
foreach ($_GET as $get_key=>$get_var) 
{ 
if (is_numeric($get_var)) { 
$get[strtolower($get_key)] = get_int($get_var); 
} else { 
$get[strtolower($get_key)] = get_str($get_var); 
} 
} 
 
foreach ($_POST as $post_key=>$post_var) 
{ 
if (is_numeric($post_var)) { 
$post[strtolower($post_key)] = get_int($post_var); 
} else { 
$post[strtolower($post_key)] = get_str($post_var); 
} 
} 
 
//Integer filter function
function get_int($number) 
{ 
return intval($number); 
} 
//String filter function
function get_str($string) 
{ 
if (!get_magic_quotes_gpc()) { 
return addslashes($string); 
} 
return $string; 
}