Often I need to work on two qgis projects at the same time. How can I launch two separate instances of QGIS?
This is not necessarily specific to QGIS but is a question I often get with QGIS users needing to reference two projects at the same time.
open a terminal window and type:
open -n /Applications/QGIS.app
Or for QGIS3, open a terminal window and type:
open -n /Applications/QGIS3.app
this format will work with any application:
open -n /Applications/Application.app
You can make an Automator script to launch as many QGIS instances as you want.
Create a new Automator application process.
Add « Run shell script action »
and type this:
If you stop the running process, QGIS will still run and you'll be able to launch a third, a fourth, etc instance of QGIS.
Under MacOS 10.15.7 Catalina, opening the app directly in Automator would not create a new instance if QGIS was already running.
This Automator code worked for me: make a new Automator Application, add "Run Shell Script" with options "Shell: /bin/zsh" and "Pass input: as arguments", with this command:
open -n -a /Applications/QGIS.app/Contents/MacOS/QGIS $argv
Save this as "QGIS New Instance.app" in your /Applications folder. This has the advantage that you can drop a file on the Automator Application and have it open in QGIS. Of course, you have to adjust the path to where you keep QGIS.