composer self-update
composer self-update 1.10.19
if ($update_needed) { shell_exec('git pull'); // additional steps to update the application }In this example, if an update is needed, the script executes the `git pull` command to update the application's code from a Git repository. This can be customized to use other methods for updating the application. Package libraries that may be used in self-update include Composer, Git, and other version control tools. The specific library used will depend on the update method chosen by the developer.