Why is my 'username2' cookie blank despite setting it using setcookie() in PHP?

Troubleshooting Blank Cookies with Session Handling

In the presented PHP function, the user validation process includes setting cookies for both 'username' and 'username2' using setcookie(). However, upon retrieving the 'username2' cookie, it remains blank. This issue can arise due to various reasons.

Incomplete Cookie Configuration

Ensure that the entire setcookie() configuration includes necessary parameters:

• Expires parameter: Specify the expiration time in a valid format. The code provided sets an expiration of 365 days, but the suggested format is time() n, where n is the number of seconds.
• Path parameter: As suggested in the solution, setting path = / ensures that the cookie applies to the entire site, not just the current directory.

Output Modification

Pay attention to the warning in the PHP manual: "cookies must be sent before any output from your script." Avoid echoing before setting cookies to prevent any headers already being sent. In the given code, echo $_COOKIE['username2']; exit(); should be placed before the header("Location: ../new.php"); line.

Validate Function Optimization

The validateUser() function should be used to set the session and redirect only, without any logic or database queries. Consider creating a separate function for user validation and another for setting cookies.

Example

An optimized version of the validateUser() function and cookie setting:

// User validation function
function validateUser($username) {
    session_regenerate_id ();
    $_SESSION['valid'] = 1;
    $_SESSION['username'] = $username;
}

// Cookie setting function
function setCookies($username, $password) {
    setcookie('username', $username, time() + 60 * 60 * 24 * 365, '/');
    setcookie('password', $password, time() + 60 * 60 * 24 * 365, '/');
}

// Function call
if(mysql_num_rows($queryreg) != 0){
    $row = mysql_fetch_array($queryreg,MYSQL_ASSOC);
    $hash = hash('sha256', $row['salt'] . hash('sha256', $password));
    if($hash == $row['password']) {
        if($row['confirm'] == 1){
            setCookies($username, $password);
            validateUser($username);
        }
    }
}

The above is the detailed content of Why is my 'username2' cookie blank despite setting it using setcookie() in PHP?. For more information, please follow other related articles on the PHP Chinese website!