How can the issue of PHP functions not having permission be resolved by adding the web server user to a specific group?

Issue: PHP functions may not have permission to perform certain actions, such as writing to a file, due to the web server user not having the necessary permissions. This can be resolved by adding the web server user to a specific group that has the required permissions. Code snippet:

// Add the web server user to a specific group
// Replace 'www-data' with the appropriate web server user
// Replace 'groupname' with the name of the specific group
exec('usermod -a -G groupname www-data');