Warp wrote:
> Darren New <dne### [at] sanrrcom> wrote:
>> Warp wrote:
>>>   (Another less fancy way would be to return a null pointer from the
>>> function, in which case the program will end with a segmentation fault.)
> 
>> Well, maybe if you're lucky. :-) Otherwise, it just goes off happily 
>> executing whatever is at memory address zero (or whatever NULL maps to).
> 
>   I'm pretty sure POSIX or some other type of standard states that jumping
> to the null pointer will always cause a segmentation fault.

But not the C standard. Try it on MS-DOS, Win 3.1, AmigaDOS, a credit 
card terminal, a cell phone, etc. :-)  Basically, you're saying you 
can't have a POSIX-compliant system without memory mapping, methinks. 
But C is used in particular because of its primitiveness and lack of 
reliance on a particular complex bit of hardware.

"The operating system is there to provide the facilities the language 
designer left out."

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

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