Re: i++ cause bad return code when result is 1

[David Lehmann]

My issue is that the resulting behavior in Exercise 1 does not make sense.

The resulting value of i should have no bearing on the exit code.  If the
addition succeeded, the expression should return 0 (success).  If i was not
an integer (e.g. i=hello), then I expect (( i++ )) to return a non-zero
error code.

...IMHO, of course.



On Mon, Aug 19, 2013 at 7:40 AM, Greg Wooledge <wooledg@eeg.ccf.org> wrote:

> On Mon, Aug 19, 2013 at 05:50:31AM +0200, Chris Down wrote:
> > On 2013-08-18 16:57, David Lehmann wrote:
> > > The ((i++)) fails only when the result is 1.  When the result is 0 or
> 2, it
> > > does not fail.  This is a problem when 'set -e'.
> >
> > This is normal and expected. If the value returned in an (( expression
> is zero,
> > then the exit code is 1. Since you're using a postincrement, zero is
> returned,
> > and then i is incremented to 1.
>
> In fact it's one of my sample cases on
> http://mywiki.wooledge.org/BashFAQ/105
> Note that whether it "works" depends on which version of bash is being
> used.
>