In addition to the local variables defined in a SIL™ program and issue variables (Variable resolution), there are environment variables. These are global constants you can access in any SIL™ program using the silEnv routine.
Declaring Environment Variables
To be able to use these variables, you have to follow two steps:
1. Environment variables must be defined in a special file named sil.properties. This file is placed in the same directory designated as sil.home (for instance the one that contains all your scripts). You must create this file manually.
2. Retrieve the value in the SIL™ program and then use it just like any other variable. Make sure you cast it to your designated type (in our case, a number).
number VAT = silEnv("VAT");
number price = customfield_10019;
print("VAT is:" + (price * VAT));