Can Someone tell me how to fix proc errors?

ID:263484
 
Feb 11 2007, 2:53 pm
runtime error: Cannot read null.PK
proc name: Kage Needle No Jutsu (/mob/needle/verb/Needle_Jutsu)
usr: Grass Feudal Lord,Scar (/mob)
src: Grass Feudal Lord,Scar (/mob)
call stack:
Grass Feudal Lord,Scar (/mob): Kage Needle No Jutsu(null)


Problem description:Here is just an example of one.

I don't get how to fix proc errors in general, and if someone could help me please, that would be appreciated.
Feb 11 2007, 5:13 pm (Edited on Feb 11 2007, 5:18 pm)
We can't tell you the solution since you haven't shown us the code you're using. Accroding to the debug the variable you were passing to your proc is null. So the bit where you call the proc, IE:

src.SillyDBZMove(mob)

Make sure 'mob' actually exists. You should always be 100% sure that mob exists before doing something with it. Basically if any time has passed what so ever (sleep or spawn) then you cannot guarantee any player exists... infact you should assume that NOTHING exists after time has passed since it's totally possible another piece of code has removed them.

Bad Example:
P.health += 10
sleep(10)
P.health += 20

This code is bad since time has passed P may no longer exist. So instead:

Good Example:
P.health += 10
sleep(10)
if(P == null) return
P.health += 20

But honestly. if you can't fix this yourself then I'm not sure how you wrote a game at all, I'm guessing you're using someone else's source. In which case you should go read the DM Guide or follow some tutorials.
Feb 11 2007, 5:34 pm
In response to Midmarch
Just to be on the safe side, you should do if(!P).