> ERROR: Unrecognized SAS option name, STDIO.

SAS doesn't support standard input/output directly from any shell does it? I've never seen it, I use the -sysin, -log -print options to redirect to /dev/stdin, /dev/stderr and /dev/stdout

e.g.

cat hello.sas | sas -sysin /dev/stdin -log /dev/stderr

Works on Unix, not sure if this will work under Cygwin. (Perhaps using /dev/conin and /dev/conout instead of /dev/stdin and /dev/stderr?)