Re: A Circle 2.2 thingy

From: Alastair Neil (ajn@essex.ac.uk)
Date: 08/10/95


>CC: Gary <gwalicze@students.uiuc.edu>
>
>> > I noticed that routines I wrote that accessed the descriptor data for a
>> > character (or a mobile) crashed when the routine attempted to access a
>> > mobile.  It sounds like this single character is crashing the game,
>> > though, however many things could be considered without knowing more
>> > about the MUD.  Seems odd that a single character would crash things..be
>> > an idea to look at the stats, see the differences and try to duplicate
>> > them bit by bit to find out what's wrong.
>>
>> First when accessing ANYTHING through a pointer, make a check to make
>> sure the pointer is not null. Accessing a null pointer is the quickest
>> way th crash your mud. As for your specific problem, descriptor_data is
>> the data about the network connection for a character, so unless someone
>> is switched into the mob your code will try to access data from a null
>> pointer and *CRASH* > -- Gary
>
>Oddly enough, though, I switched into a mobile and it still crashed.  And
>when I switched into a linkless player, the routines worked just fine.  I
>suspect that mobiles aren't equipped with a non-NULL descriptor, and
>linkless PCs have non-NULL descriptors but are nullified in operation
>rather than in pointer.
>
>I suspect exploring the code further would answer these curiosities.

Often these problems arise because MOBS don't have a skills array
allocated in their stucture so if you try to reference the skills
known by a pc with a mob stucture BOOM!



--
Ich habe Dinge gesehen, die ihr Menschen niemals glauben wuerdet. Gigantische
Schiffe, die brannten draussen vor der Schulter des Orion. Und ich habe
C-Beams  gesehen - glitzernd im Dunkeln nahe dem Tannhaeuser Tor. All diese
Momente werden verloren sein in der Zeit...so wie Traenen im Regen.
                                Zeit zu sterben... 



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