${...%%=*} problem

${...%%=*} problem

[Andrej Borsenkow]

bor@itsrm2% print ${foo%%=*}
zsh: * not found

Why?

-andrej

Re: ${...%%=*} problem

[Sven Wischnowsky]

Andrej Borsenkow wrote:

> bor@itsrm2% print ${foo%%=*}
> zsh: * not found
> 
> Why?

Because it does expansion, include the one after an equal sign:

  % echo =*
  zsh: * not found

Yeah, I know, this seems silly, and I had to learn that the hard way,
too (when starting with the completion system I sometimes forgot to
quote that `=' with a backslash...).


Bye
  Sven


-- 
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de

RE: ${...%%=*} problem

[Andrej Borsenkow]

>
> > bor@itsrm2% print ${foo%%=*}
> > zsh: * not found
> >
> > Why?
>
> Because it does expansion, include the one after an equal sign:
>

This violates our own documentation:

They are followed by _process
substitution_, _parameter expansion_, _command substitution_,
_arithmetic expansion_ and _brace expansion_ which are performed in one
step in left-to-right fashion.  After these expansions, all unquoted
occurrences of the characters `\', `'' and `"' are removed, and the
result is subjected to _filename expansion_ followed by _filename
generation_.

and later

If a word begins with an unquoted `=' and the EQUALS option is set, the
remainder of the word is taken as the name of a command or alias.  If a
command exists by that name, the word is replaced by the full pathname
of the command.

Granted, we do not have strict definition of ``word'' (as opposed to POSIX
:-). In this context I suspect it more like POSIX ``field''. Still, =
expansion happens after parameter substitution - not at the same time (and,
actually, here it happens even before).

-andrej

Re: ${...%%=*} problem

[Bart Schaefer]

On Jun 7, 11:29am, Andrej Borsenkow wrote:
} Subject: RE: ${...%%=*} problem
}
} > > bor@itsrm2% print ${foo%%=*}
} > > zsh: * not found
} > >
} > > Why?
} >
} > Because it does expansion, include the one after an equal sign:
} 
} This violates our own documentation:

You're sort of correct, but you quoted the wrong section of the doc.
The relevant bit is this, under parameter expansion:

 In the expansions discussed below that require a pattern, the form of
 the pattern is the same as that used for filename generation; see *Note
 Filename Generation::.  Note that these patterns, along with the
 replacement text of any substitutions, are themselves subject to
 parameter expansion, command substitution, and arithmetic expansion.

That paragraph should include "filename expansion" (but not generation)
among the list of things to which the patterns are subject.  So

	${foo##~}

removes the home directory from $foo.

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

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net