Just to make sure I'm understanding it...

Just to make sure I'm understanding it...

[DervishD]

    Hi all :))

    I'm reading some zsh functions I have here, just for learning
some more of zsh. Heck, I *really* like this shell...

    Well, in function 'insert-files' there is a line, just at the
beginning, that reads 'files=( *(N) )', and I want to make sure I
understand it. Since it starts with a parenthesis, it is (AFAIK) a
candidate for filename generation. The asterisk seems to be the
pattern an the 'N' in the parentheses is a glob qualifier (namely the
'set NULL_GLOB for this pattern' qualifier). What I don't understand
is, why the spaces around the pattern and the qualifier?

    Am I missing anything else? Am I plainly wrong?

    Thanks a lot in advance. Really the power of zsh is far bigger
than I expected when I switched to it ;))

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/

Re: Just to make sure I'm understanding it...

[Peter Stephenson]

DervishD wrote:
>     Well, in function 'insert-files' there is a line, just at the
> beginning, that reads 'files=( *(N) )', and I want to make sure I
> understand it. Since it starts with a parenthesis, it is (AFAIK) a
> candidate for filename generation. The asterisk seems to be the
> pattern an the 'N' in the parentheses is a glob qualifier (namely the
> 'set NULL_GLOB for this pattern' qualifier). What I don't understand
> is, why the spaces around the pattern and the qualifier?

They're optional, they're just there for readability.

  files=(*(N))

will work but looks like the logo of a secret society.  What you're
probably missing is the the outer parentheses are there to turn the
assignment into an array assignment, they're nothing to do with
globbing.  In this case the place where you can't have spaces is around
the `='.

  files=(
     *(N)
  )

works, too.  It's one of the advantages of arrays --- you can make the
assignments much neater.

However,

  files=*(N)

*doesn't* work.  The right hand side of normal assignment doesn't do
globbing (unless you have the option GLOB_ASSIGN set, which we don't
recommend).  This was changed a while ago: the problem was that if there
were multiple matches, an array assignment was done, while if there was
just one, because of the use of scalar syntax a scalar assignment was
done.  The new arrangement (with GLOB_ASSIGN unset) is much neater.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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Re: Just to make sure I'm understanding it...

[DervishD]

    Hi Peter :)

 * Peter Stephenson <pws@csr.com> dixit:
> > is, why the spaces around the pattern and the qualifier?
> They're optional, they're just there for readability.

    OK, nice. I thought that it had to do with something about the
globbing...

> What you're
> probably missing is the the outer parentheses are there to turn the
> assignment into an array assignment, they're nothing to do with
> globbing.

    Oops. I thought that they where there for introducing a filename
generation. I thought I read it in the manual, but I'm not sure...
Yes, I know. In the manual says that if a word contains an unquoted
instance of a '*', '(', etc... it is regarded as a pattern for
filename generation, and I interpreted (wrongly) that 'if a word
starts'. My fault, sorry O:)

> The new arrangement (with GLOB_ASSIGN unset) is much neater.

    Yes, you're true. Well, thanks a lot again for your fast and
informative answer. I'm just amazed about how powerful zsh is, and
learning all that power is difficult (at least for me), so is very
comforting for me to know that zsh gurus like you give a helping hand
to zsh clueless (like me) ;))) Free software is fantastic.

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736
http://www.pleyades.net & http://raul.pleyades.net/