PHP Login and Logout statement tutorial and example script code

Depending on the visitors session condition whether user is logged in or not we can display different messages to the members. We should show an welcome messages to a logged in user like "Welcome john" with a logout button. Same way we if the member has not logged in then we can show login input box in that place or show the link to login page.

Checking session status in PHP to show login or logout link to the user and allowing access to page.

We can check the visitors session variable and display a login or logout link using one PHP IF condition. This is one example of php if and see detail Login script for full code. We will be using PHP isset function to check the existence of session variable.

Read more on PHP Session variables here

There are two types of pages here.
One is when user is logged in, we will display welcome message with logout link and for others ( not logged in ) a login link.
For example the home page of the site where member is not yet logged in but can check the content of the page

if((isset($_SESSION['userid']) and strlen($_SESSION['userid']) > 5)){

 echo "Welcome $_SESSION[userid]  <a href=setting.php>Settings</a> . <a href=logout.php>Logout</a>";

}else{

echo "<a href=signup.php>Sign UP</a>  <a href=login.php>Login</a>";

}

Second one is for the pages where content can be accessed only by login members. So if the page is opened without login then we will not execute the content of the page and we will show the link to login page with a message. For example change password page or update profile page.

if((isset($_SESSION['userid']) and strlen($_SESSION['userid']) > 5)){

// Content of the page

}else{

echo "Please <a href='login.php?redirect=post.php'>Login</a> to post any topics";

}

Using multiple pages

There may be several pages where we will be restricting access to login members only. So to maintain access over multiple pages we will keep the code in a common file and include the file when ever required. This will help us in easy maintenance of site.

Let us see how we will add login status to pages.

require "check.php";

Inside the check.php file we will keep this code.

<?Php
if(!(isset($_SESSION['userid']) and strlen($_SESSION['userid']) > 2)){
echo "Please <a href=g_login.php>login</a> to use this page ";
exit;
}else{
echo "Welcome $_SESSION[userid] | <a href='logout.php'>Logout</a>|<a href='change.php'>Change Password</a>";
}
?>

Now we can included the check.php file from our ( at top of )all required secure pages.

require "check.php";

Subhendu Mohapatra

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Moses	24-10-2014
I am new to php.Could you explain the database part too please.

PHP Login and logout script and example

Using multiple pages

Subhendu Mohapatra