Date: Tue, 6 Oct 1998 00:52:43 +0100 (BST)
From: George Foot <george DOT foot AT merton DOT oxford DOT ac DOT uk>
To: Chris Yewchuk <cyewchuk AT calum DOT csclub DOT uwaterloo DOT ca>
cc: djgpp AT delorie DOT com
Subject: Re: Text Output Problem..
In-Reply-To: <36193B3E.1F87173A@csclub.uwaterloo.ca>
Message-ID: <Pine.OSF.4.05.9810060028110.4537-100000@sable.ox.ac.uk>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Reply-To: djgpp AT delorie DOT com

On Mon, 5 Oct 1998, Chris Yewchuk wrote:

> The problem is that no text is printed to the screen until the program
> terminates.  Almost like there is an output buffer that isn't being
> flushed until the program terminates.  The getch()'s work okay, but
> there is no text until the end of the program, at which time all the
> text that was supposed to be displayed throughou the program is dumped
> as one long string.

That is exactly what is happening.

> Has anyone encountered this before?  I'm tried using printf and cout for
> printing to stdout.  Am i doing something wrong?

By default stdout is line buffered.  This means that nothing
gets printed until (1) the buffer is full; (2) a newline
character is sent; (3) the buffer is flushed.  The buffer can be
flushed in C by calling fflush(stdout).  I don't know about C++.

The buffer is automatically flushed by stdio functions like
`scanf', but not by conio functions like `getch'.  It's best to
avoid mixing stdio and conio input/output functions.

Possible solutions if you want to continue mixing the functions:
  a) Turn off the buffering on startup (`setvbuf' can do this)
  b) Explicitly flush the buffer (`fflush(stdout)')
  c) Send a newline character ('\n')

Even after using any of these, it's best not to mix the
functions.

-- 
george DOT foot AT merton DOT oxford DOT ac DOT uk

xu do tavla fo la lojban  --  http://xiron.pc.helsinki.fi/lojban/lojban.html