On Sun, Feb 28, 2021 at 06:51:53PM -0500, Sean Anderson wrote:
> On 2/28/21 6:40 PM, Heinrich Schuchardt wrote:
> > Am 28. Februar 2021 22:29:51 MEZ schrieb Sean Anderson <sean...@gmail.com>:
> > > If there were no variable substitutions in a command, then initial
> > > assignments would be misinterpreted as commands, instead of being
> > > skipped
> > > over. This is demonstrated by the following example:
> > >
> > > => foo=bar echo baz
> >
> > The commit message does not explain why this patch is needed.
>
> This is a bug I noticed while writing some tests of hush.
>
> > What shall be the value off foo after this line?
>
> It should be bar. This is an existing difference when compared with
> bash. For example, without this patch, we have
>
> => foo=bar echo $foo
> bar
> => echo $foo
> bar
>
> >
> > What will be the output of
> >
> > foo=bar echo ${foo}
> >
> > with and without yor patch?
>
> It is the same.bash works as you describe. dash and busybox-sh both function like this: $ foo=bar echo $foo $ echo $foo $ That we error out entirely is different from everyone. Is that a good thing? Maybe. I know I've caught myself making thinkos due to that logic. It does also violate the principal of least surprise, that we don't act like anything else. But I would suggest the behavior of busybox-sh (what we forked long long ago) is what we should model here rather than be more bash-like. I'm not all that firm on this opinion frankly, especially given the one-line nature of the change to bring us that behavior and I assume dash/busybox are acting like pure sh would in this case, which we aren't anyhow. -- Tom
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