"Harald van Dijk via austin-group-l at The Open Group"
<austin-group-l@opengroup.org> wrote:
> >> $ bosh -c 'case x in ( (x) echo match ;; esac'
> >> bosh: syntax error at line 1: `(' unexpected
> >
> > It may be that you are missinterpreting the results.
>
> I'm not. You say there's no state change that happens as a result of the
> first opening parenthesis. However, before the first opening
> parenthesis, an opening parenthesis is accepted, while after the first
> opening parenthesis, an opening parenthesis is not accepted. Since the
> two states differ in what they accept, they cannot be the same state.
> Therefore, the opening parenthesis did cause a state change.
Given that only "(" is thrown away without modifying internal variables, there
is no state change.
> > The problem here is that the lexer sees the '(' as a separate token and
> > thus it
> > is seen as pattern. The next token is the "x" and since "x" is neither ')',
> > nor '|', this syntax is not accepted.
>
> The error message in both bosh and ksh is "`(' unexpected". This error
> message means the shell rejected the '(' token, not whatever follows. Of
> course it did: a pattern cannot be any arbitrary token, it has to be
> what the standard calls a "word", which '(' is not.
Well, I should have been a bit more specific.
The code is:
if (wdval || (word() != ')' && wdval != '|'))
synbad();
and wdval is the return value from the previous word() call. Wdval is == 0
in case that the parsed word is recognized as a string. As I mentioned, '(' is
not recognized as a string as I mentioned before.
Jörg
--
EMail:jo...@schily.net Jörg Schilling D-13353 Berlin
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