[Klug-general] C problem with delay and erase in Ubuntu terminal & Code::Blocks.

[JACKSON MALCOM]

Hello Dan,

Works a treat. Very grateful,

I will read through the link you sent me.

All the best,

Malcolm.

On 31 July 2012 22:16, Daniel Ellis <mail at danellis.co.uk> wrote:

> Hi Malcom, welcome to the group.
>
> After trying out your example, I noticed the same behavior which I
> didn't expect.  Then I found:-
>
>
> http://stackoverflow.com/questions/1716296/why-does-printf-not-flush-after-the-call-unless-a-newline-is-in-the-format-strin
>
> So fflush is what you need here, for example:-
>
> printf("Hello world!");
> fflush(stdout);
>
> Regards,
> Dan Ellis
>
> On 31 July 2012 21:36, JACKSON MALCOM <malcom.jackson at ntlworld.com> wrote:
> >
> > Hello all,
> > I have just joined KLUG, being very keen on learning about  Ubuntu and
> > Linux.
> >
> > I have run up against a problem whilst  working through Ivor Hortons book
> > Beginning C, 3rd edition, using Terminal and CodeBlocks 10.04, on 11.04
> > 'Natty Narwhal'.
> > There have been a couple of problems such as getchar and buffering that I
> > have managed to get solved on line, but now on Page 180 I have hit a
> brick
> > wall.
> >
> > There is a sample program called Simple Simon.
> >
> > Simple Simon is a memory game that posts a sequence of numbers on the
> screen
> > for you to memorise. After 1 second the numbers are erased, and you have
> to
> > key in what you remember, and hope that you have remembered correctly.
> >
> > I have not been able to get the program working on terminal or through
> code
> > blocks, despite several days of trying to find out what is wrong.
> > A couple of days ago I decided to start from scratch and write my own
> > version of the program, building up a bit at a time and perhaps find out
> why
> > the original program won't work for me.
> >
> > The problem I have  is with the following piece of code which should
> give a
> > 1 second delay and then erase the previously printed sequence of numbers.
> > (This code works OK on XP and Vista):-
> >
> > #include <stdio.h>
> > #include <stdlib.h>
> > #include <time.h>
> >
> >  int main()
> >    {
> >      long now = 0;
> >      printf("Hello world!");
> >      now = clock();
> >
> >      for(;clock() - now<CLOCKS_PER_SEC;  );       /*After 1 second delay
> > this "*/
> >          printf("\r");
> > /*"code should erase  the string "Hello world!" */
> >          printf(" ");
> >
> > return 0;
> > }
> >
> > I have tried all sorts of delay methods, but they all end up not doing
> what
> > I want to do.
> > Instead of writing Hello world! on the screen and erasing it after 1
> second,
> > the screen comes up and after 1 second Hello world! is printed and
> erased at
> > the same instant.
> > I put a break in before the delay, and can see Hello world! is indeed
> > printed.
> >
> > On XP and Vista this program works correctly.
> >
> > I have checked through the man pages, but don't yet know enough to know
> if I
> > have found an answer or not. Nothing I have tried works, so would be
> > mightily obliged if some one will let me know what to do to get this
> > working.
> > Many thanks,
> > Malcolm Jackson.
> >
> > --
> > Hello Ubuntu ...... Goodbye  Microsoft.
> > malcom.jackson at ntlworld.com
> >
> > _______________________________________________
> > Kent mailing list
> > Kent at mailman.lug.org.uk
> > https://mailman.lug.org.uk/mailman/listinfo/kent
>
> _______________________________________________
> Kent mailing list
> Kent at mailman.lug.org.uk
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>



-- 
Hello Ubuntu ...... Goodbye  Microsoft.
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