Re: Assigning to BASHPID fails silently

[Chet Ramey]

On 10/19/16 5:53 PM, Martijn Dekker wrote:
> Op 19-10-16 om 15:18 schreef Chet Ramey:
>> On 10/17/16 2:38 PM, Martijn Dekker wrote:
>>> bash 4.4.0 (I did not investigate other versions) does not produce an
>>> error message if you try to assign something to the BASHPID readonly
>>> using either arithmetic or normal assignment. Other readonlies produce a
>>> message on an assignment attempt. BASHPID seems to be an exception.
>>
>> BASHPID is a dynamic variable.  There should be a sentence in the man
>> page that says assignments to it have no effect (as it does for GROUPS
>> and FUNCNAME, for example).
> 
> Assigning to BASHPID most certainly does have an effect. Since you
> didn't quote that part, I think you might have missed my point that
> attempting this will silently exit the shell without any error message,

This is a consequence of it being marked as readonly, and you running it
in a configuration where assignment errors cause the shell to exit.  It
shouldn't be marked as readonly, and it should be documented that
assignments to it are discarded.

> In what possible context would assigning to any of these variables make
> sense, or be an indication of anything other than a fatal bug in the
> script? I think they should all be readonly, and produce a proper
> diagnostic error message upon exit if assigning is attempted.

OK, you've made your position clear.

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