one or two run

Is there a way to give a encrypted lisp program as a trial that would only run one or two time then corrupt ,delete or erase its self?

run one or two time then corrupt ,delete or erase its self

Yes, yes, yes.

I would not go down the delete path, rather use number of goes or by date, simple way would be to read & write to the registery and read a number if 11 dont work any more. There is examples here about using registery entries.

Thanks I found this

(setq datst (rtos (getvar "cdate") 2 0))

(setq date-string

(strcat

(substr datst 5 2)

"/"

(substr datst 7 2)

"/"

(substr datst 1 4)

)

)

Thanks I found this

 

 

(setq datst (rtos (getvar "cdate") 2 0))

(setq date-string

(strcat

(substr datst 5 2)

"/"

(substr datst 7 2)

"/"

(substr datst 1 4)

)

)

how do you use this?

I think Mike55 thought about using the date retrieved programmatically to limit the usage allowance; a code for this may be:

(if (> (getvar "cdate") 20140618)
(progn
 (alert "The limit was June 18, 2014")
 (exit)
)
)

However this will not control the number of calls.

Please don't miss also that the date is retrieved from system, so this solution can be very easily circumvented.

Like Msasu says date is easy to reset and just reload program resets it also, as I hinted a better way is to write to the registery a number increment each time. Say give them ten goes doesn't matter if they reload set clock etc using a compiled lisp FAS unless they know about checking the registery for added entries this is probably 99.9999% good. There is some posts here with code how to make a reg key and retrieve will need to serach for them, pretty sure under same theme protecting code.

Bigal you are right I do like write to the registry better.

I tried to use the # tag but it did not work?

(if (not (getenv "MyDemo"))

(setenv "MyDemo" "1")

(setenv "MyDemo" (itoa (1+ (atoi (getenv "MyDemo"))))))

(if (> (atoi (getenv "MyDemo")) 10)

(progn

(alert "You Have Exceeding to Demo Time")

(exit)))

Just a bit of spelling

(alert "You Have Exceeded Your Demonstration Time")

I tried to use the # tag but it did not work?

You will have to select the code excerpt and next press the "#" button. Or just write "[/code]" and its end, respectivelly "

[/i]" at beginning.