Message-ID:	<001901be6d5b$3fee83c0$195d44ce@computer>
From:	"Sean Middleditch" <sean DOT middleditch AT usa DOT net>
To:	<djgpp AT delorie DOT com>
Subject:	Re: Passing/updating pointers...
Date:	Sat, 13 Mar 1999 09:10:27 -0500
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Reply-To:	djgpp AT delorie DOT com

I'm not exactly sure what you mean, but what I think you're trying to say is
that you need to change the address pointed to by the pointer passed as an
argument to a function...

void
ChangeString ( char *Str ) {
    Str = SomethingElse;
}

In which the value of Str changes.  To do this, pass a pointer to a pointer:

void
ChangeString ( char **Str ) {
    *Str = SomethingElse;
}

And when you call the function, pass the address of the pointer:
int
main ( void ) {
    char *String = "Some Text";

    ChangeString ( &Str );
}

Hope I could help.

Sean Middleditch
 of
AwesomePlay Productions
http://www.angelfire.com/biz/aweplay
aweplay AT iname DOT com

-----Original Message-----
From: Thomas J. Hruska <shinelight AT detroit DOT crosswinds DOT net>
Newsgroups: comp.os.msdos.djgpp
To: djgpp AT delorie DOT com <djgpp AT delorie DOT com>; buzdor AT email DOT com
<buzdor AT email DOT com>
Date: Saturday, March 13, 1999 1:50 AM
Subject: Passing/updating pointers...


>I have never quite figured out how to pass a pointer to a function and have
>the function update the variable sent to it.  So, for many years I have
>just found ways to work around this little glitch in my memory.  Now, I
>have come to a point in a program that I'm writing where I can't work
>around the problem anymore.
>
>Here is what I want to do:
>
>// Read a line of text from buffer in memory and return string
>char *LineInput(char *src)
>{
>  char *dest, src2;
>
>  src2 = src;
>..
>  [update input pointer (src) with src2]
>  return dest;
>}
>
>So, how would I go about doing this?  That is, how would I call the
>function and how would I perform the update?
>
>
>        Thomas J. Hruska -- shinelight AT detroit DOT crosswinds DOT net
>Shining Light Productions -- "Meeting the needs of fellow programmers"
>         http://www.geocities.com/SiliconValley/Heights/8504
>                    http://click-on.to/shinelight
>
>

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