If you’re receiving the error “Could not open input file: artisan” or words to the same effect, you may be missing the Artisan file altogether.
Navigate to your project in terminal and run a cURL on the raw Artisan file.
curl -L 'https://raw.githubusercontent.com/laravel/laravel/v5.5.0/artisan' > artisan
This will pull the Artisan script from GitHub to your local project.
Note: where I’ve used version 5.5.0 you will need to change the tag version