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From: john@dynasoft.UUCP (John Stanley)
Newsgroups: comp.sys.atari.st
Subject: Re: more on strncpy (was re: laser c question)
Message-ID: <1989Dec18.124932.1486@stag.UUCP>
Date: 18 Dec 89 12:49:32 GMT
Sender: daemon@stag.UUCP (The devil himself)
Organization: Mindtools ST Access Group
Lines: 38

[kirkenda@.cs.pdx.edu (Steve Kirkendall) writes...]
> 
> In article <1870@calvin.cs.mcgill.ca> depeche@calvin.cs.mcgill.ca (Sam Alan EZUST) writes:
>>someone already sent me dlibs memcpy which I believe is what is used
>>in Sozobon.... However, I don't have an assembler and am not too
>>much of an expert in it anyway, so I couldn't get it installed on
>>my system without help.
> 
> Okay, here's one in C:
> 
> 	memcpy(dest, src, count)
> 		register char	*dest;	/* destination address */
> 		register char	*src;	/* source address */
> 		register int	count;	/* number of bytes to copy */
> 	{
> 		while (--count >= 0)
> 			*dest++ = *src++;
> 	}
> 
> This can copy up to 32767 bytes at a time.  It isn't very fast, though.

  Actualy, it can copy up to 65535 bytes if you change:

		while (--count >= 0)
	into
 		while (count-- != 0)

  While the parameter passed to memcpy is usualy documented to be just an
int, it's not uncommon for versions of memcpy to treat the count variable
as an unsigned integer instead which doubles the amount to memory that
can be moved with a single call...

  (Before you use this, be sure your code isn't going to have to deal
with copying negative numbers of bytes... only 1/2 :^)

---
John Stanley <dynasoft!john@stag.UUCP>
Software Consultant / Dynasoft Systems