How to update core and all modules and themes from CLI? On a LAMP environment I have a Drupal 8.5.6 website which is nearly all-core with the Bartik theme and a few stable contrib modules. Nothing is customized and I have daily backups so I don't "fear" of updating anything in one go this time.

I tried drush up * but got:


  Command "up" is ambiguous.


I didn't find an update command in Drupal Console documentation.

How could I upgrade all in one go from the CLI?
Assuming you are using Composer to maintain your Drupal 8 installation, you can use the following command to update core and all modules (and dependencies).
composer update drupal/* --with-dependencies

If you started you project from &quot;drupal-composer/drupal-project&quot; the command becomes the following.
composer update drupal/* webflo/drupal-core-require-dev --with-dependencies

I recommend reading https://www.drupal.org/docs/8/update/update-core-via-composer and https://www.drupal.org/docs/8/update/update-modules.
Always after updating, don't forget to run database updates and rebuild the cache.
drush updatedb
drush cache:rebuild

If you started your Composer project from drupal/drupal as the user guide says, you are in trouble, since drupal/core isn't listed as installed. You could try to use Composerize Drupal to fix the problem.
If you started your project from a tar-ball, you also need use Composerize Drupal if you don't plan to do manual updates forever.
Drush 9 doesn't support updating core or modules. It will tell you to use Composer. Anyway, reading the Drush docs is very useful.