Re: Shell case statements

[Chet Ramey]

On 5/19/11 6:09 PM, Eric Blake wrote:
> [adding bug-bash]
> 
> On 05/16/2011 07:23 PM, Wayne Pollock wrote:
>> (While cleaning up the standard for case statement, consider that it is 
>> currently
>> unspecified what should happen if an error occurs during the expansion of the
>> patterns; as expansions may have side-effects, when an error occurs on one
>> expansion, should the following patterns be expanded anyway?  Does it depend 
>> on
>> the error?  It seems reasonable to me that any errors should immediately 
>> terminate
>> the case statement.)
> 
> Well, that's rather all over the place, but yes, it does seem like bash
> was the buggiest of the lot, compared to other shells.  Interactively, I
> tested:
> 
> readonly x=1
> case 1 in $((x++)) ) echo hi1 ;; *) echo hi2; esac
> echo $x.$?
> 
> bash 4.1 printed:
> bash: x: readonly variable
> hi1
> 1.0
> which means it matched '1' to $((x++)) before reporting the failure
> assign to x, and the case statement succeeded.  Changing the first "1"
> to any other string printed hi2  (the * case).

Thanks for the report.  This was an easy fix.  The variable assignment
error was actually handled correctly, the expression evaluation code
just didn't pay enough attention to the result.

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