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
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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