How to get running operating system

from terminal and get a long printout.

If you just look for a specific line you could run the command using CPIPE and read it line by line until you get your info

details on CPIPE here: Execute Server Commands from Caché / Ensemble / IRIS

For Linux/Unix I don't have that at hands

something fast for WINDOWS

and for Linux:

(don't have a Caché  installation at hands)  but  CPIPE should do it

You can use $version(1) to see if it is Windows (returns '2') or UNIX (returns '3').  If you want to get really fancy you can include %occOptions.inc and then use the $$$isUNIX and $$$isWINDOWS calls (which just check to see if $version(1) is 2 or 3).

Personally, I like using ##class(%Studio.SourceControl.ISC).RunCmd() as it wraps the capture of the output for parsing.

You can tie $version together the other answers into something that is platform independent (warning, I haven't tested this, but I believe the pieces work):

If ($version(1)=2) {

   //Is Windows

   set sc=##class(%Studio.SourceControl.ISC).RunCmd("Ver",.out,0)

   set OS = out(1)

   // exercise of parsing exact desired version piece from the string is an exercise left to the reader

} elseif ($version(1)=3) {

   //Is UNIX

   set sc=##class(%Studio.SourceControl.ISC).RunCmd("uname -a",.out,0)

   set OS = out(1)

   // exercise of parsing exact desired version piece from the string is an exercise left to the reader

}