Why Use `exit;` After `header('Location: ...')` in PHP Redirection?

Redirection After header('Location') in PHP: Why Use exit?

In PHP, redirection of users can be achieved using the header function. While it's common practice to include exit; after header('Location: ...'), it's necessary to understand why this is crucial.

Is Code After header() Executed?

Yes. The header command is simply a request to the browser to redirect. The remaining page content will still be generated by PHP and delivered to the client unless the browser prevents the header command from executing.

Can Code After header() Be Effectively Ignored?

Yes. Clients using command-line tools like wget can avoid following redirects by specifying the -o option to suppress them. This means that any code beyond the header() call can still be received and viewed by the client.

Malicious Users and Header Avoidance

Malicious users with access to the client's browser or network can circumvent the header redirection. By disabling JavaScript, using browser extensions, or altering network configurations, they can prevent the browser from executing the header command and view any content or code that follows it.

The Role of exit

The purpose of including exit; after header() is to prevent PHP from continuing to execute any additional code that shouldn't be rendered to the client. By doing so, it ensures that the user is immediately redirected and malicious activities are prevented.

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