Hello everyone,

I am just looking for ideas on how I can implement a demo version of my program which will be available in unix environment (solaris and linux).

So what I have in mind is to either implement a limited-time version (trial version expires after 30 days) or a limited-number version (trial version expires after the program has ran for 'x' number of times)

Can anyone please give any idea on how any of this this can be implemented ?

The simplest strategy I can think of is to store a number (for e.g: the date or a count) in a file when the program is run for the first time and then on each subsequent run, read this number and, lets say if its a date, then compare it with the current date.

But then I ran into issues like, where can I store this file? (I want the strategy atleast a little secure, so that it is not very obvious to everyone to go ahead and delete this file whenever the trial version expires) ? Is it possible the program does not have write permission ? Is there any kind of a registry in unix where I can store key, value pairs ?

(Actually, I am not so much concerned about crackers being able to break the demo version, it just should not be too obvious)

Please, just throw in whatever ideas you have.

Thanks !!