SPDL files are automatically validated when a shader or plug-in is installed. You can, however, validate them manually using spdlcheck which is a command-line program that allows you to debug your SPDL files independently of Autodesk Softimage. It is recommended that you run spdlcheck anytime you edit a SPDL file.
The spdlcheck utility is in the %XSI_HOME%\Application\bin directory. The last argument to spdlcheck is the SPDL file name:
spdlcheck myspdl.spdl
For information about available options run:
spdlcheck -h.
The spdlcheck utility prints warnings and compiler errors if there are problems in the SPDL file. For example missing ";" characters or mismatched braces are detected. However, although a successfully compiled SPDL file has correct syntax, it may still contain semantic problems that means it would not work in Softimage. This is analogous to an English sentence which passes all spelling and grammar checks but still not make any "sense".
Autodesk Softimage v7.5