The validate command takes a single parameter, which is the path to the file containing the protocol description to be validated.

For example, if the user is in the top level folder of the Scribble tools distribution, without the bin folder being added to the system path, then the following command can be executed to validate one of the sample protocol descriptions:

bin/validate.sh samples/purchasing/Purchasing.spr

When this command is performed initially, it will complete without any errors. However
if you edit the samples/purchasing/Purchasing.spr file, and change
the following line:

	Order from Buyer to Seller;

For example, change the Seller role to
Seller2, and then re-run the validate
command. This will result in the following error messages:

ERROR: [line 12] Unknown role 'Seller2'