From:	alaric AT abwillms DOT demon DOT co DOT uk (Alaric B. Williams)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Messing with strings
Date:	Wed, 19 Mar 1997 06:52:18 GMT
Message-ID:	<332efc8e.10220125@news.demon.co.uk>
References:	<01bc332c$d1b4dcc0$452349c2 AT default>
NNTP-Posting-Host:	abwillms.demon.co.uk
Lines:	32
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

On 17 Mar 1997 23:42:20 GMT, "Thomas Harte" <T DOT Harte AT btinternet DOT com>
wrote:

>	Anyway, I want to know, how, in DJGPP, do you shift every value of a
>variable down one in a dimension, ie so that the value at x[n] is written
>to x[n+1], the value at x[n+1] to x[n+2], and so on. I could write a
>for/next routine type thing, but this would be slow. Is there a way similar
>to memcpy ? Like I said, on other compilers because I did not know the
>command, I would just mess with the positions in RAM, but that is not
>something I can get to work under protected mode.

Hmm, for an array A of length L:

memmove(A+1,A,(L-1)*sizeof(A[0]));

memmove differs from memcpy in that it is guaranteed to work for
overlapping blocks such as this. This makes it a little slower, but it
will work in the above case; memcpy merely /might/ :-)


ABW
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Alaric B. Williams Internet : alaric AT abwillms DOT demon DOT co DOT uk
<A HREF="http://www.abwillms.demon.co.uk/">Hello :-)</A>

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