Re: ((...) && (...)) parsing confused by line break

[Chet Ramey]

Tim Waugh wrote:

> Machine Type: i386-redhat-linux-gnu
>
> Bash Version: 3.0
> Patch Level: 16
> Release Status: release
>
> Description:
>         https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=146638
>
>         This script fails:
>
> ( (echo line1) \
> && (echo line2))
> ((echo line3) && (echo line4))
> ((echo line5) \
> && (echo line6))
>
>          like this:
>
> line1
> line2
> line3
> line4
> test.sh: line 5: syntax error near unexpected token `'
> test.sh: line 5: `&& (echo line6))'
>
>         It seems as though the problem line might be being treated as
>         though it is a ((...)) compound command, rather than nested
>         subshells.

Of course it is.  It's inherently ambiguous.  Bash does its best,
and is able to disambiguate in the case where everything appears on
one line (since it's already been read and is available for analysis),
but you can certainly fool it if you try hard enough.

Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
( ``Discere est Dolere'' -- chet )
                                                Live...Laugh...Love
Chet Ramey, ITS, CWRU    chet@po.CWRU.Edu 
http://cnswww.cns.cwru.edu/~chet/