Double quote (") should not be escaped in CIVICRM_UF_DSN in civicrm.settings.php
I'm a complete newbie to both CiviCRM and Drupal, but I've been trying to test out an installation for one of my clients. I completed a fresh, standard installation of Drupal 7, then followed the installation process for CiviCRM in the System Administrator Guide.
Once installation was complete, and I had filled in all the details of my database paths and users as requested, I tried to follow the process for setting up scheduled jobs at https://docs.civicrm.org/sysadmin/en/latest/setup/jobs/ using either the CLI or HTTP method.
Whatever I tried, every attempt to run Job.execute resulted in 'DB Error: connect failed'.
With the help of this StackExchange thread (https://civicrm.stackexchange.com/questions/25575/db-error-connect-failed-when-trying-to-call-job-execute-using-cli-php/) I tracked down the logs and discovered that MySQL was rejecting the password of the Drupal database user.
On looking up the password in CIVICRM_UF_DSN in civicrm.settings.php I noticed that a double quote character (") in my password was escaped with a backslash, even though the instructions in the file only say single quote (') or backslash () characters should be escaped. Taking the backslash out of the password allowed Job.execute to run as expected.
I had never touched civicrm.settings.php before, so it seems that whichever script had translated the password I entered in the GUI during installation into that file must have erroneously escaped the double quote.