Date: Wed, 1 Apr 2009 10:39:46 +0200 (CEST) From: Oliver Fromme <olli@lurza.secnetix.de> To: freebsd-questions@FreeBSD.ORG, Polytropon <freebsd@edvax.de>, Gary Kline <kline@thought.org> Subject: Re: Why?? (prog question) Message-ID: <200904010839.n318dkuJ050633@lurza.secnetix.de> In-Reply-To: <20090331210142.7dcb52ec.freebsd@edvax.de>
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Polytropon <freebsd@edvax.de> wrote:
> FreeBSD defines additional exit codes to specify the reason for
> exiting more precisely in /usr/include/sysexits.h - for your
> example, exit(EX_USAGE); would be a good exit code.
Actually, no. The purpose of the <sysexits.h> codes is for
communication between SMTP processes (e.g. between an MTA
such as sendmail and a delivery agent such as procmail), so
the MTA can determine the meaning (severity) of the error
and how to proceed.
The only standard exit codes for "normal" programs are
EXIT_SUCCESS and EXIT_FAILURE. You should use these.
> [where to put braces]
> In fact, I'm sticking to the concept that only the highest level
> of "code groupers" deserve a new line {: these are functions in
> C and class methods in C++. Everything else has the { appended
> (after a space) to the construct that causes the {. So if you find
> a }, you only need to look up. It's obvious that a } is caused
> by a {, but you want to know the construct that made it appear,
> for example if(), while(), a struct definition or something similar.
> With this concept at hand, looking up will make you find this
> construct in question at the first glance.
Of course this is purely a matter of taste and personal
preference. My preference is similar to yours, but my
main reasoon is to save space. I think it is a ridiculous
waste of space if every third line consisted only of a
sole brace (opening or closing). To my eye, such lines
that are almost empty break the natural structure of a
piece of source code. I insert empty lines quite often
in order to group source lines logically, but brace lines
break that grouping visually.
That's probably one of the reasons why I like Python so
much: There are no braces for source structuring at all.
This allows me to write very compact code _and_ structure
it logically at the same time, making it easily readable
and comprehensible. Furthermore, Python gets rid of all
of the brace problems that C has, e.g. relating an "else"
to the wrong "if" when multiple "if" statements are nested,
and forgetting to add braces when you add a second line to
an "if" branch (unless you always use braces in C, even
when they're superfluous, but again that's a waste of
space and does not really improve readability).
I could go on for hours, but this is really off-topic now,
so we should take this to the -chat list (or to private
mail).
Best regards
Oliver
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"One of the main causes of the fall of the Roman Empire was that,
lacking zero, they had no way to indicate successful termination
of their C programs."
-- Robert Firth
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