Many possibilities:
- use as a simple calculator with vectors, tensors etc.
- test validity of expression syntax
As a calculator:
foamCalc '(vector(1,2,3) ^ vector(4,5,6)) * sqrt(34)'
The same, but with debugging:
foamCalc -debug-switch fieldExpr=6 \
'mag((vector(1,2,3) ^ vector(4,5,6))) * sqrt(34)'