noglob and setting variables

noglob and setting variables

[Owen M. Astley]

Is this a bug or a feature?

In a directory with 32 files...

alpha3-~% a=(*)
alpha3-~% echo $#a
32
alpha3-~% noglob a=(*)
zsh: command not found: a=(*)
alpha3-~% noglob set -A a *
alpha3-~% echo $#a
1

So assignment using '=' doesn't appear to be a command.  What is it
then?

This is on zsh-3.0.5.

Owen

Re: noglob and setting variables

[Bart Schaefer]

On Aug 4,  7:01pm, Owen M. Astley wrote:
} Subject: noglob and setting variables
}
} Is this a bug or a feature?

Neither, really ...

} alpha3-~% noglob a=(*)
} zsh: command not found: a=(*)
} 
} So assignment using '=' doesn't appear to be a command.  What is it
} then?

It's an assignment.  The manual says:

    A "simple command" is a sequence of optional parameter assignments
    followed by blank-separated words, with optional redirections
    interspersed.  The first word is the command to be executed, and the
    remaining words, if any, are arguments to the command.

The arguments to "noglob" are interpreted as a command to be executed and
its arguments, not as a complete "simple command."  This is a consequence
of a decision made by Zoltan way back in June 1996, that "noglob" would
become a builtin rather than a reserved word.  (PWS actually wrote the
patch.)

Before that, the form you tried probably did work, but things like

    zsh% FOO=exec ; $FOO something

did NOT work, because of the order in which globbing and subsitutions had
to be done (or not) when parsing a line of input.  See zsh-workers/1229 in
the archives, and follow the thread back and forth.

In addition to `noglob set -A a *` another way to get the effect you want
is

    zsh% : ${(A)a=*}


-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com