Fast code and no morals ( Really exit() semantics )

[Josh Knight]

 > Date: 17 Feb 86 14:46:00 PST
 >
 > > Date:     Sat, 15 Feb 86 21:43:34 EST
 > >
 > > If VMS does not support exit(0) as successful termination,
 > > then VMS is WRONG and needs to fix their exit() routine.
 > >           Doug Gwyn (VLD/VMB) <gwyn at BRL.ARPA>
 >
 > I know this is naive, but then this flock is full of naive users...
 > Doug, where exactly do Kernighan & Ritchie specify the semantics of
 > the exit() procedure ?
 >
 > The common semantics seem to me to be "return to the surrounding
 > operating system level, using the argument value as the return code".
 > Unfortunately for portability, UN*X and VMS have different ideas about
 > the semantics of program return codes, but you can't say VMS is WRONG
 > just because it's DIFFERENT unless you can quote chapter and verse.
 >
 > Does the ANSI draft specify semantics for system calls ?
 >
 >             / Lars Poulsen
 >               Advanced Computer Communications
 >              <Lars @ ACC.ARPA>
 >

Chapter and verse:


>From ANSI C Standard Draft Version dated 11 August 1985,
Section D.10.4.2, "The exit function" (third paragraph):

     Finally, control is returned to the host environment.  If the
     value of *status* is zero, the status returned is *successful
     termination*; otherwise an implementation-defined form of the
     status *unsuccessful termination* is returned.

>From K&R, Chapter 7, Section 7, "Error Handling - Stderr and Exit"
p. 154, next to the last paragraph:

     The program also uses the standard library function *exit*, which
     terminates program execution when it is called.  The argument of
     *exit* is available to whatever process called this one, so the
     success or failure of the program can be tested by another program
     that uses this one as a sub-process.  By convention, a return value
     of 0 signals that all is well, and various non-zero values signal
     abnormal situations.



Of course, any opinions, expressed or implied are mine and not my
employers...

			Josh Knight
			IBM T.J. Watson Research Center
josh at yktvmh.BITNET,  josh.yktvmh at ibm-sj.arpa