Docker unknown shorthand flag: 'a' in -aq)
Solution 1:
You can also run your command - docker stop $(docker ps -aq)
in PowerShell or Git Bash; I would think the command fails because the $(docker ps -aq)
part of the command is Linux command and windows CMD does not know how to translate that.
Solution 2:
In your Windows shell, you can do:
FOR /f "tokens=*" %i IN ('docker ps -q') DO docker stop %i
Taken from other question: Stop all docker containers at once on Windows