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Date: Thu, 03 Feb 2011 12:03:59 +0100
From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
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Subject: Re: How do I write directly to a memory address?
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Date: 2011-02-03T12:03:59+01:00
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On 03.02.11 09:24, Ludovic Brenta wrote:

>> unsigned int print(char *message, unsigned int line)
>> {
>>         char *vidmem = (char *) 0xb8000;
>>         unsigned int i= 0;
>>
>>         i=(line*80*2);
>>
>>         while(*message!=0) // 24h
>>         {
>>                 vidmem[i]= *message;
>>                 *message++;
> 
> *Every* time I look at C code, I see a bug.
> I think this is a bug; it should read "message++" since you want to
> increment the pointer, not the pointed-to character.

This is not a bug, since postfix ++ has higher precedence than *.
Indeed, *t++ = *s++; is idiomatic C.

While the result of the * operation on the pre-incremented pointer
doesn't seem to have a visible effect in this program, it still might
be intended, the intention possibly being to read the contents of
(possibly volatile) location *message, ahead of time.  Who knows?
It might just as well be a c&p issue.