Is it possible to test (from within FME) which operating system an FME workspace is running on?
Python has these properties or method.
See the links. One of them might help you.
I thought we had a published parameter for this, but I guess not. If you want to distinguish between Windows and Linux the best I can offer is the FME_MF_DIR parameter - if it starts with "C:\\" then you can be fairly certain it's a Windows platform.
The FME_OS parameter now may be what you need to use -
FME_OS Returns the operating system on which FME is running - Windows, macOS, or Linux.
The ks_rootpath attribute can be used in the file path of readers and writers, making the workspace OS independent. That is, you can run the same workspace on any platform without modifying paths.
e.g. @Value(ks_rootpath)/Projects/GIS_TaskRequest/@Value(ProjectNam)/summary.txt