How to complete commands on a different/generated PATH ?

How to complete commands on a different/generated PATH ?

[C. v. Stuckrad]

HI!

I installed zsh3 on our systems, and therefore went through
the new compctl examples. I am missing a special kind of completion
which might be trivial, but I could not (yet :-) find out:

We use a set of macros 'x11x' 'ow3x' '...some_other_s', which
manipulate the environment to start a program in the 'correct world'.
('x11x' starts original X11-Progs under Openwin, 'ow3x' the other way...
 all those reorder the PATH to 'prefer' the given environment).

Now if you do NOT have X11 in YOUR PATH and run a completion on the
partial command 'x11x x<tab>'  completion does not search in the correct
place. I would need to 'pre-evaluate' the 'x11x' macro to get it's new
PATH and glob THEREIN! OK, getting that PATH might be done simply by
'x11x echo "$path"' as I asume there is an evaluate in 'x11x'.

BUT HOW TO  'first change the PATH, then glob on the new PATH' ?

 Thanks for a HINT , your's Stucki

Christoph von Stuckrad       * *  | talk to  | <stucki@math.fu-berlin.de> \
Freie Universitaet Berlin    |/_* | nickname | ...!unido!fub!leibniz!stucki|
Fachbereich Mathematik, EDV  |\ * | 'stucki' | Tel:+49 30 838-7545{9|8}    |
Arnimallee 2-6/14195 Berlin  * *  |  on IRC  | Fax:+49 30 838-5913        /

Re: How to complete commands on a different/generated PATH ?

[Bart Schaefer]

On Aug 28,  5:22pm, C. v. Stuckrad wrote:
} Subject: How to complete commands on a different/generated PATH ?
}
} We use a set of macros 'x11x' 'ow3x' '...some_other_s', which
} manipulate the environment to start a program in the 'correct world'.
} 
} BUT HOW TO  'first change the PATH, then glob on the new PATH' ?

The best way to do this depends on what you mean by "macro".  If it's
nothing more than a zsh alias that expands to a PATH=... assignment,
there might be some tricks to play.  However:

----------

function Xcomplete {
    emulate -R zsh
    setopt localoptions
    local nword args
    read -nc nword
    read -Ac args
    reply=($(
	case $args[0] in
	(x11x) PATH=the:path:used:by:x11x ;;	# Change these suitably for
	(ow3x) PATH=the:path:used:by:ow3x ;;	# each of your macros' PATH
	esac
	rehash
	whence -pm ${args[$nword]:t}\*
    ))
    reply=(${reply##*/})
}
compctl -x 'p[1]' -K Xcomplete - 'p[2,-1]' -l '' -- x11x ow3x

----------

Note the use of the new "case" syntax.  There is STILL a bug in parsing
of "case" statements inside $( ... ) which causes the old-style "case"
to fail.  Vis:

zsh% echo $(
cmdsubst> case foo in
cmdsubst> foo)
zsh: parse error near `foo'
zsh: parse error in command substitution

The close-paren in the "case" pattern ends the $( ... ) parse.

Of course, this doesn't work in bash either, and is probably the
reason that POSIX created the new case syntax ....

Oh, there is one small nit about the above function:  Because of the
way "whence" works, it returns x11x, ow3x, and Xcomplete as possible
completions.  So you can end up with:

zsh% x11x x11x ow3x ...

and it'll still be happily completing away.  You can use extend it to
strip those out if you want.

-- 
Bart Schaefer                             Brass Lantern Enterprises
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