Sounds like quite a project in and of itself. On 04/27/2017 10:18 PM, Joh-Tob Schäg wrote: > I thought about the same. > My insights are: > You can 'let all relevant symbols with alternative functions or just > NIL. Adresses 1 & 2 > You might want to change the repl in a way that if for example the > symbols car and list are evaluated they return a meaningless number. (It > might be possible to calculate the offset and execute arbitrary lisp > code.) 1 & 2 > And alternative would be to rewrite the picolisp eval function and only > let it load Symbols from a certain namespace/symbol to function property > list. > Regarding 3: the best way to archieve that is putting the execution of > this code in a 'later. You can either cancel them after a certain time > via kill while your game world goes on (ask regenaxer how the open pipe > is handled or wait for the result) 3 execution time aspect. > To controll the space aspect you need rewrite picolisp in picolisp and > maintain your own free list or let all functions the user can call > either increase a counter on each allocation and throw an error if the > number of allocations exhausts the virtual machine capacity. > > Am 28.04.2017 04:18 schrieb "Christopher Howard" > <christopher.how...@qlfiles.net <mailto:christopher.how...@qlfiles.net>>: >> >> Hi list, I was wondering if there would be a practical way to safely >> contain a picolisp interpreter (or some subset of commands) inside >> another picolisp program. E.g., suppose you have a computer game >> programmed in PicoLisp, and the main character found a computer terminal >> that allowed him to run some commands or program something in PicoLisp >> The obvious safety concerns here are: >> >> (1) You either want to disable disk access, or make it so that disk >> access pulls from a virtual disk in the game. >> >> (2) You don't want the user to be changing memory in the game itself, >> only his virtual memory. >> >> (3) You don't want the user to be able to exhaust memory or blow the > stack. >> >> -- >> https://qlfiles.net >> >> -- >> UNSUBSCRIBE: mailto:picolisp@software-lab.de > <mailto:picolisp@software-lab.de>?subject=Unsubscribe >
-- Christopher Howard, Computer Assistant Alaska Satellite Internet 3239 La Ree Way, Fairbanks, AK 99709 907-451-0088 or 888-396-5623 (toll free) fax: 888-260-3584 mailto:christop...@alaskasi.com http://www.alaskasatelliteinternet.com -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe
