From:	ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Main + Void
Date:	14 Mar 1997 09:02:05 GMT
Organization:	The National Capital FreeNet
Lines:	29
Message-ID:	<5gb46d$gnv@freenet-news.carleton.ca>
References:	<01bc2f01$9891dc60$7cae71a5 AT mod DOT exo DOT com>
Reply-To:	ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
NNTP-Posting-Host:	freenet3.carleton.ca
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

As an example of the pitfalls of not returning an explicit value from
main: this program

// mainrett.c
int main (int argc, char *argv[]) {
  // do nothing and see what gets returned.
}

compiles (but has a warning, no return from function not returning void).
If I run redir -x mainrett, I get this:
Exit code: 2

GCC, for whatever reason, defines the implicit return value as 2. If
people expect 0, a program that lets gcc choose the return value of
main could break some batch files.
(Don't forget what the int is *for*. It's the errorlevel. All my programs
return 0 on normal exit, 1 on error like malloc failure or file not found
or argument syntax error, or if arguments were expected, display a usage
note and return 1, and return 255 on any protection faults, this last
being dictated by CWSDPMI and not my code.)


--
    .*.  Where feelings are concerned, answers are rarely simple [GeneDeWeese]
 -()  <  When I go to the theater, I always go straight to the "bag and mix"
    `*'  bulk candy section...because variety is the spice of life... [me]
Paul Derbyshire ao950 AT freenet DOT carleton DOT ca, http://chat.carleton.ca/~pderbysh

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