mysqli_real_escape_string and stripslashes returning blank variables

Question

I am using the following code to clean any variables that get returned from forms. I recently swapped over from mysql to mysqli but as a result the function below is now stripping my variables back to being blank.

//Start session
session_start();

//Include database connection details
require_once('config.php');

//Array to store validation errors
$errmsg_arr = array();

//Validation error flag
$errflag = false;

//Connect to mysql server
$link = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD);
if(!$link) {
    die('Failed to connect to server: ' . mysqli_error());
}

//Select database
$db = mysqli_select_db($link,DB_DATABASE);
if(!$db) {
    die("Unable to select database");
}

//Function to sanitize values received from the form. Prevents SQL injection
function clean($str) {
    $str = @trim($str);
    if(get_magic_quotes_gpc()) {
        $str = stripslashes($str);
    }
    return mysqli_real_escape_string($link,$str);
}

//Sanitize the POST values
$login = clean($_POST['login']);
$password = clean($_POST['password']);

//Input Validations
if($login == '') {
    $errmsg_arr[] = 'Login ID missing';
    $errflag = true;
}
if($password == '') {
    $errmsg_arr[] = 'Password missing';
    $errflag = true;
}

//If there are input validations, redirect back to the login form
if($errflag) {
    $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
    session_write_close();
    header("location: login-form.php");
    exit();
}

So every time I type in a valid username and password it redirects me back to the login page saying that both fields were in fact blank. The moment I remove the 'clean' function around the POST values it starts working again.

I'm new to mysqli however I can't see what I'm doing wrong. Can anyone help?

Thanks

Answer 1

1. You shouldn't show your DB info.

2. Try to do:

    mysql_real_escape_string