Process exit status on different platforms

Process exit status on different platforms

[Lennart Borgman]

Are there any variable that could be used to check if call-process
exited with success status?

Is not this return value platform dependent?



BTW a small manual bug on page (info "(elisp) Synchronous Processes"):

 -- Function: call-process program &optional infile destination display
          &rest args
     This function calls PROGRAM in a separate process and waits for it
     to finish.

This is wrong since it does not wait if destination is 0.

Re: Process exit status on different platforms

[Davis Herring]

[Sorry this reply is so much delayed; perhaps it will nevertheless be
useful.]

> Are there any variable that could be used to check if call-process
> exited with success status?

I don't know of any.

> Is not this return value platform dependent?

Not much.  VMS is the only system I know of that doesn't use the "0 means
success, and everything else means some kind of failure but there's little
to no convention" convention.  I think it uses 1 for success and 44 for
catastrophic failure (with other values for minor problems), but that's
just from a very little searching.  (It's worth noting, as the glibc
manual says, that 1 means "successfully found differences" in diff and the
like, and it means merely "no matches" in grep and the like:
http://www.gnu.org/software/libc/manual/html_node/Exit-Status.html)

Davis

-- 
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shipping.

Re: Process exit status on different platforms

[Lennart Borgman]

On Tue, Feb 23, 2010 at 9:18 PM, Davis Herring <herring@lanl.gov> wrote:
> [Sorry this reply is so much delayed; perhaps it will nevertheless be
> useful.]
>
>> Are there any variable that could be used to check if call-process
>> exited with success status?
>
> I don't know of any.
>
>> Is not this return value platform dependent?
>
> Not much.  VMS is the only system I know of that doesn't use the "0 means
> success, and everything else means some kind of failure but there's little
> to no convention" convention.  I think it uses 1 for success and 44 for
> catastrophic failure (with other values for minor problems), but that's
> just from a very little searching.  (It's worth noting, as the glibc
> manual says, that 1 means "successfully found differences" in diff and the
> like, and it means merely "no matches" in grep and the like:
> http://www.gnu.org/software/libc/manual/html_node/Exit-Status.html)


Thanks, at the moment I can't remember exactly why I asked ... eh, yes I do ;-)

I think it will be useful to simplify at least my bug hunting.