This is great, thank you Evgeny!!  Here is another one that I use, often from the Output window in Studio in order to execute an OS-level command (I most frequently use this for p4 commands to interact with my Perforce server from my IRIS server).  IIRC, original credit goes to @Timothy Leavitt 

Kill stream Set sc = ##class(%Studio.SourceControl.ISC).RunCmd("<insert OS Command here>",.stream,,1) w ! do stream.OutputToDevice() If 'sc {​​​​​ Write $System.Status.GetErrorText(sc) }​​​​​

All - please note the new Practice Questions have been added to this post as an attachment, and that the opening up of the Beta Test has been announced:

https://community.intersystems.com/post/beta-test-intersystems-ccr-techn...

If anyone hasn't registered as a beta tester yet and would like to do so, please email certification@intersystems.com

@Jeffrey Drumm - it is important to have this run from a process that is already running in the InterSystems IRIS instance (or something spun off from the SuperServer) so that it doesn't pick up your UNIX username if you enter via console.  So being able to run an API like Tim's will work nicely as I can run it via the Output window from Studio: