Arithmetic expressions and subshells

Arithmetic expressions and subshells

[Hrvoje Niksic]

There are cases when zsh is not able to see correctly whether an
expression is a `((...))' let-substitute, or embedded subshells.  Here
is a message describing it from gnu.bash.bug, which well applies to
zsh.  I think the case mentioned is quite reasonable, and that a
change should be thought of.

What do you think?

------- Start of forwarded message -------
From: oliva@dcc.unicamp.br (Alexandre Oliva)
Subject: Re: [50 character or so descriptive subject here (for reference)]
Date: 14 Jan 1997 16:28:20 -0200
Organization: IC - UNICAMP - Campinas, SP, Brazil
Message-ID: <oru3ok9kmz.fsf@dcc.unicamp.br>
References: <199701102345.AAA01140@papa.home>
Newsgroups: gnu.bash.bug

Stefan Seibold writes:
> 	sh -c '((/usr/local/bin/raplayer /tmp/MO32.ram); rm /tmp/MO32.ram)&'
> 	This are the errors reported by bash:
> 	sh: -c: line 1: missing closing `)' for arithmetic expression

I've seen several bug reports on this problem, and I think it would be
worth implementing a change in the grammar:

`((' should only be considered an expression if it were matched by a
`))'.  If a single `)' were found, then whatever is between the parens
would be considered a command list.

Does anyone know how hard it would be to implement this?

-- 
Alexandre Oliva
mailto:oliva@dcc.unicamp.br mailto:aoliva@acm.org
Universidade Estadual de Campinas, SP, Brasil
------- End of forwarded message -------