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Date:      Tue, 27 Jul 2004 06:29:17 +0300
From:      Giorgos Keramidas <keramida@ceid.upatras.gr>
To:        Sergey Babkin <babkin@bellatlantic.net>
Cc:        freebsd-arch@freebsd.org
Subject:   Re: some PRs
Message-ID:  <20040727032917.GA24942@gothmog.gr>
In-Reply-To: <4105987E.5FC50517@bellatlantic.net>
References:  <20040718184008.GC57678@darkness.comp.waw.pl> <20040719075952.GG57678@darkness.comp.waw.pl> <20040719.081356.51946167.imp@bsdimp.com> <200407191855.19885.max@love2party.net> <4105987E.5FC50517@bellatlantic.net> <20040727032253.GA24778@gothmog.gr>

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On 2004-07-26 19:49, Sergey Babkin <babkin@bellatlantic.net> wrote:
> Max Laier wrote:
> > The question to me is, do we really want to support (read fertilize)
> > such a stupid thing? Given the chance that once we do support it
> > people will use it.  In my opinion it is bad to integrate something
> > into base that we agree is nothing one should ever have created (at
> > least that's my reading of the thread so far). I see no user-pessure
> > for this.
>
> I'm about a week behind :-) but here are my 2 cents: it's a VERY
> useful device for testing. Not checking the error code of write(),
> printf() and such is a typical bug, so making it easy to detect by
> switching the output to /dev/full (or creating a symlink to it) is a
> very good idea. Like this:
>
>   yourprogram >/dev/full \
>      && echo "The program does not check for success of write()"

If a program doesn't check the return code of write() but merrily goes
on doing other stuff or even terminates with a zero return value, how
will the redirection affect its operation?  I think it won't, as shown
in the test below (run on a Linux machine):

: $ ls -ld /dev/full
: crw-rw-rw-    1 root     root       1,   7 Jun 14 00:24 /dev/full
: $ cat -n lala.c
:      1  #include <sys/types.h>
:      2  #include <string.h>
:      3  #include <unistd.h>
:      4
:      5  int
:      6  main(void)
:      7  {
:      8      char buf[] = "hello world\n";
:      9      size_t len;
:     10
:     11      len = strlen(buf);
:     12      write(1, buf, len);
:     13      return 0;
:     14  }
: $ cc -O -W -Wall -o lala lala.c
: $ ./lala
: hello world
: $ ./lala >/dev/full
: $ echo $?
: 0
: $

The fact that /dev/full was used as the output device didn't reveal the
potential write() problem.

I must have misunderstood something.  How do you mean that we could use
/dev/full for testing?



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