Re: forking madness

Path	csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: forking madness
Date	Tue, 03 Mar 2015 09:44:31 -0800
Organization	None to speak of
Lines	37
Message-ID	<878ufe562o.fsf@kst-u.example.com> (permalink)
References	<md2sfm$f67$1@reader1.panix.com> <md4oer$o8u$1@speranza.aioe.org>
Mime-Version	1.0
Content-Type	text/plain; charset=utf-8
Content-Transfer-Encoding	8bit
Injection-Info	mx02.eternal-september.org; posting-host="c77ff4d35e33d1c939d3461ebde8dd0d"; logging-data="8781"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX198SFrlebximXeepz5JUBuZ"
User-Agent	Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux)
Cancel-Lock	sha1:5vmQt2COKhy5xHQZJvAojTBUir8= sha1:XBRx5ew1UNyj+dlZ0pBGLJ98p6A=
Xref	csiph.com comp.lang.c:57855

Show key headers only | View raw

Lőrinczy Zsigmond <nospam@for.me> writes:
> I don't really get what your question is, but I suggest
> you don't use printf/puts when multiprocessing,
> instead try something like this
> (handle==1 for stdout, handle==2 for stderr):
>
> static void mylog (int handle, const char *fmt, ...)
> {
>     char buff [1024];
>     int len;
>     va_list ap;
>
>     va_start (ap, fmt);
>     len= vsnprintf (buff, sizeof (buff), fmt, ap);
>     va_end (ap);
>     if (len<0 || (size_t)len>=sizeof (buff)) len= (int)sizeof(buff);
>     write (handle, buff, len);
> }
>
> Note: if you want to write into file, use append mode
> (eg ./myprog >>logfile) not to lose messages.

I presume the point of that is to avoid buffering, so output appears
immediately.

What is the advantage of your (POSIX-only) solution over the standard

    printf("Your message here\n");
    fflush(stdout);

?

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Thread

forking madness Ruben Safir <mrbrklyn@panix.com> - 2015-03-02 23:41 +0000
  Re: forking madness Keith Thompson <kst-u@mib.org> - 2015-03-02 16:05 -0800
    Re: forking madness fir <profesor.fir@gmail.com> - 2015-03-03 01:20 -0800
      Re: forking madness Noob <root@127.0.0.1> - 2015-03-03 15:50 +0100
        Re: forking madness fir <profesor.fir@gmail.com> - 2015-03-03 07:57 -0800
      Re: forking madness Nobody <nobody@nowhere.invalid> - 2015-03-07 07:07 +0000
        Re: forking madness fir <profesor.fir@gmail.com> - 2015-03-07 05:05 -0800
  Re: forking madness Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-03-02 19:25 -0500
    Re: forking madness Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-03-02 19:32 -0500
    Re: forking madness ruben <nowhere@nowhere.nor> - 2015-03-03 14:56 +0000
      Re: forking madness Keith Thompson <kst-u@mib.org> - 2015-03-03 07:54 -0800
    Re: forking madness asetofsymbols@gmail.com - 2015-03-05 00:03 -0800
      Re: forking madness asetofsymbols@gmail.com - 2015-03-05 00:21 -0800
        Re: forking madness asetofsymbols@gmail.com - 2015-03-05 00:44 -0800
  Re: forking madness Lőrinczy Zsigmond <nospam@for.me> - 2015-03-03 17:45 +0100
    Re: forking madness Keith Thompson <kst-u@mib.org> - 2015-03-03 09:44 -0800
      Re: forking madness Lőrinczy Zsigmond <nospam@for.me> - 2015-03-03 19:06 +0100
        Re: forking madness James Kuyper <jameskuyper@verizon.net> - 2015-03-03 13:57 -0500
          Re: forking madness Lőrinczy Zsigmond <nospam@for.me> - 2015-03-04 06:53 +0100
            Re: forking madness Chad <cdalten@gmail.com> - 2015-03-05 14:09 -0800

csiph-web