From: Jonathan Foster <jgf1 AT ukc DOT ac DOT uk>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: sprintf() string length?
Date: Thu, 16 Oct 1997 09:53:55 +0100
Organization: University of Kent at Canterbury, England
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Peter Palotas wrote:
> 
> Is there a way to find out the length of the string that sprintf() will
> generate, without writing it anywhere? i.e. if I want to dynamically
> allocate the storage space for the string this would be very good (read
> essential) to know!
> 
> -- Peter Palotas alias Blizzar -- blizzar AT hem1 DOT passagen DOT se --

I once read a solution to this (can't remember where though!):

The "fprintf" command will return the number of characters output,
and you should fopen DOS's "NULL" file to send the output to.
"NULL" is a "black hole" which will swallow and ignore anything you
send to it.  Although "NULL" never appears in a directory, it
exists everywhere.  (I think the UNIX equivalent is "/dev/nul",
but I've never used UNIX.)

-- 
   Jon Foster.

(1st Year Maths/Computer Science Student)