SQL인젝션 방지 함수

// sql_escape_string 함수에서 사용될 패턴
define('G5_ESCAPE_PATTERN',  '/(and|or).*
(union|select|insert|update|delete|from|where|limit|create|drop).*/i');
define('G5_ESCAPE_REPLACE',  '');

// multi-dimensional array에 사용자지정 함수적용
function array_map_deep($fn, $array)
{
    if(is_array($array)) {
        foreach($array as $key => $value) {
            if(is_array($value)) {
                $array[$key] = array_map_deep($fn, $value);
            } else {
                $array[$key] = call_user_func($fn, $value);
            }
        }
    } else {
        $array = call_user_func($fn, $array);
    }
    return $array;
}

// SQL Injection 대응 문자열 필터링
function sql_escape_string($str)
{
    if(defined('G5_ESCAPE_PATTERN') && defined('G5_ESCAPE_REPLACE')) {
        $pattern = G5_ESCAPE_PATTERN;
        $replace = G5_ESCAPE_REPLACE;
        if($pattern)
            $str = preg_replace($pattern, $replace, $str);
    }
    $str = call_user_func('addslashes', $str);
    return $str;
}

//==============================================================================
// SQL Injection 등으로 부터 보호를 위해 sql_escape_string() 적용
//------------------------------------------------------------------------------
// magic_quotes_gpc 에 의한 backslashes 제거
if (get_magic_quotes_gpc()) {
    $_POST    = array_map_deep('stripslashes',  $_POST);
    $_GET     = array_map_deep('stripslashes',  $_GET);
    $_COOKIE  = array_map_deep('stripslashes',  $_COOKIE);
    $_REQUEST = array_map_deep('stripslashes',  $_REQUEST);
}


// sql_escape_string 적용
$_POST    = array_map_deep(G5_ESCAPE_FUNCTION,  $_POST);
$_GET     = array_map_deep(G5_ESCAPE_FUNCTION,  $_GET);
$_COOKIE  = array_map_deep(G5_ESCAPE_FUNCTION,  $_COOKIE);
$_REQUEST = array_map_deep(G5_ESCAPE_FUNCTION,  $_REQUEST);

출처
https://m.blog.naver.com/PostView.naver?isHttpsRedirect=true&blogId=kf80s&logNo=220897478841