Re: return exit code in EXIT trap

[Chet Ramey]

On 8/6/22 12:05 AM, Robert Elz wrote:
> I am actually astounded by all of this - both by what is in the
> standard, and the way Chet interpreted it.
>
> The language in the standard for return was clearly based upon the
> idea that it should act just the same as exit, which is not really
> appropriate.

It's a logical conclusion from the requirement that the trap action be
executed as if you had dropped an `eval action' into the function, or
wherever the shell is executing when the trap is processed.


> Return is nothing like that - it isn't even
> clear that it is specified (not even when the trap fires when a function is
> running) that a return in the trap handler can do any more then cause the
> function it is lexically defined within to return (which does not mean the
> function that happened to be running at the time).   That to me looks
> unspecified (in at least the latest wording).

The requirement that it be equivalent to `eval action' whenever it's
executed seems like it has some pretty specific implications.

> The language in POSIX is clearly broken, and needs fixing.  What's kind of
> amazing is that none of the "primary" austin group people made any responses
> at all to the mailing list discussion.
>
> Clearly this needs a posix defect report filed, if no-one else does that
> today, I probably will.

Please do. The behavior is all over the place, and it seems like every
shell has exceptions to

"The value of "$?" after the trap action completes shall be the value it
had before trap was invoked."

Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/