Analyze the PHP functions that control user login and determine user login in WordPress_php skills

Login function: wp_signon()

Function introduction:
The wp_signon() function is used to authorize users to log in to WordPress and remember the user name. This function replaces wp_login. Enabled from WordPress version 2.5.

Function usage:

<&#63;php wp_signon( $credentials, $secure_cookie ) &#63;> 

Parameter description:

• $credentials
• (array) (optional) Login user information.
• Default: None
• $secure_cookie
• (boolean) (optional) Determines whether to use secure cookies.
• Default: None

Note: If you do not provide $credentials, wp_signon uses the $_POST parameter (the key values ​​are "log", "pwd" and "rememberme").

Function return value:
(object)
The object WP_Error is returned if the login fails, and WP_User

is returned if the login is successful.

Function example:

$creds = array();
$creds['user_login'] = 'example'; //wordperss后台用户名称
$creds['user_password'] = '123456'; //wordperss后台用户密码
$creds['remember'] = true;
$user = wp_signon( $creds, false );
if ( is_wp_error($user) )
  echo $user->get_error_message();

Source file:
wp_signon() is located in wp-includes/user.php.

Function to determine whether the user is logged in: is_user_logged_in()

Function introduction:
The is_user_logged_in() function determines whether the user is logged in. If the user is logged in, it returns True otherwise it returns False.

Function usage:

<&#63;php if ( is_user_logged_in() ) { ... } &#63;> 

Function parameters:
This function does not accept any parameters.

Return value:
(boolean)
Returns True if logged in, otherwise returns False.

Function example:
The following example shows the content displayed by logged in users or non-logged in users:

<&#63;php
if ( is_user_logged_in() ) {
  echo 'Welcome, registered user!';
} else {
  echo 'Welcome, visitor!';
}
&#63;>

Source file:
is_user_logged_in() is located in the file wp-includes/pluggable.php.