You would believe that a company that sells software licenses for thousands of Euros would make it as easy as possible for their users to use their software once they have rightfully acquired a license. With ITTVIS’s IDL this is unfortunately not the case. Instead of selecting the license file with a file picker you have to do all sorts of tricks if you want to use IDL with your laptop while on the way.
Since I was lucky to get a machine-specific license for this software (that is needed for data reduction in astronomy) and was then struggling to get the software to find the license file, I here want to briefly describe what I did to make it run.
I placed the license file into /Applications/itt/license/license.dat, edited /etc/hosts so that it includes the line