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Re: compile C programs for both sunstudio and Visual studio

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Keith Thompson <kst-u@mib.org> writes:
> Ian Collins <ian-news@hotmail.com> writes:
> > On 07/19/11 11:41 AM, Nobody wrote:
> >> On Mon, 18 Jul 2011 15:34:03 +0200, Heinrich Wolf wrote:
> >>> clear() is defined on Unix in curses.h
> >>
> >> If you just need to clear the screen, linking against curses is overkill.
> >> system("clear") is the way to go here (and the usual warnings about
> >> system() don't really apply here).
> >
> > Why is using a library function "overkill" compared to spawning a new 
> > process just to clear the screen?
> 
> Perhaps because curses tends to be used by programs that need
> complete control over the screen, including keeping track of what
> character appears at every position, whereas clearing the screen
> is a much simpler operation.
> 
> The time it takes to spawn a process isn't likely to be significant.

What if the spawning of the process will cause cgroups to notify 
a user-space agent which will then potentially do re-jigging of
other processes properties? You're context switching all over the
place unnecessarily.

However, one technique I've seen in the past is to use system() to
call 'clear' or whatever, but rather than letting what it produces
just go to the controlling terminal, it's been read into the C program
and cached. Then to actually clear the screen, you just print out
the cached sequence. That at least reduces your system()s to 1.

Phil
-- 
"At least you know where you are with Microsoft."
"True. I just wish I'd brought a paddle." -- Matthew Vernon

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compile C programs for both sunstudio and Visual studio happytoday <ehabaziz2001@gmail.com> - 2011-07-17 22:49 -0500
  Re: compile C programs for both sunstudio and Visual studio Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-18 12:34 +0100
    Re: compile C programs for both sunstudio and Visual studio "Heinrich Wolf" <invalid@invalid.invalid> - 2011-07-18 15:34 +0200
      Re: compile C programs for both sunstudio and Visual studio Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-18 14:53 +0100
        Re: compile C programs for both sunstudio and Visual studio Virchanza <virtual@lavabit.com> - 2011-07-18 07:31 -0700
          Re: compile C programs for both sunstudio and Visual studio Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-18 15:38 +0100
            Re: compile C programs for both sunstudio and Visual studio Kenneth Brody <kenbrody@spamcop.net> - 2011-07-18 14:08 -0400
              Re: compile C programs for both sunstudio and Visual studio Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-18 19:18 +0100
      Re: compile C programs for both sunstudio and Visual studio Nobody <nobody@nowhere.com> - 2011-07-19 00:41 +0100
        Re: compile C programs for both sunstudio and Visual studio Ian Collins <ian-news@hotmail.com> - 2011-07-19 11:47 +1200
          Re: compile C programs for both sunstudio and Visual studio Keith Thompson <kst-u@mib.org> - 2011-07-18 19:08 -0700
            Re: compile C programs for both sunstudio and Visual studio Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-22 14:58 +0300
              Re: compile C programs for both sunstudio and Visual studio Keith Thompson <kst-u@mib.org> - 2011-07-22 09:42 -0700
                Re: compile C programs for both sunstudio and Visual studio Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-22 22:32 +0300
                Re: compile C programs for both sunstudio and Visual studio Keith Thompson <kst-u@mib.org> - 2011-07-22 13:16 -0700
          Re: compile C programs for both sunstudio and Visual studio Nobody <nobody@nowhere.com> - 2011-07-19 12:56 +0100
    Re: compile C programs for both sunstudio and Visual studio Kenneth Brody <kenbrody@spamcop.net> - 2011-07-18 14:06 -0400
    Re: compile C programs for both sunstudio and Visual studio Keith Thompson <kst-u@mib.org> - 2011-07-18 11:11 -0700
  Re: compile C programs for both sunstudio and Visual studio Geoff <geoff@invalid.invalid> - 2011-07-18 18:06 -0500
  Re: compile C programs for both sunstudio and Visual studio "Waldek M." <wm@localhost.localdomain> - 2011-07-18 18:07 -0500
  Re: compile C programs for both sunstudio and Visual studio BGB <cr88192@hotmail.com> - 2011-07-18 18:07 -0500
  Re: compile C programs for both sunstudio and Visual studio "io_x" <a@b.c.invalid> - 2011-07-19 17:40 -0500
    Re: compile C programs for both sunstudio and Visual studio "io_x" <a@b.c.invalid> - 2011-07-20 10:43 +0200
    Re: compile C programs for both sunstudio and Visual studio "io_x" <a@b.c.invalid> - 2011-07-30 01:48 -0500
    Re: compile C programs for both sunstudio and Visual studio Kenneth Brody <kenbrody@spamcop.net> - 2011-07-30 01:48 -0500
  Re: compile C programs for both sunstudio and Visual studio "io_x" <a@b.c.invalid> - 2011-07-19 17:40 -0500

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