Re: [gentoo-dev] Re: I want to steal your tools

[Thomas de Grenier de Latour <degrenier@easyconnect.fr>]

On 2008/02/04, Ryan Hill <dirtyepic@gentoo.org> wrote:
> 
> Can someone provide a tool that given a package name simply prints
> the category or cat/pkg, or if ambiguous, prints the multiple
> cat/pkgs or returns an error code?  I don't care what it's written in
> as long as it's relatively quick.

As long as you're only interrested in stuffs from the Portage tree,
and not overlays, and you have portage-utils installed along with its
post-sync hook, you can use one of this function:

find_cat1() {
   qsearch -CsN "^${1}$"
}

find_cat2() {
   sed -n "\\|/${1}/|s:/[^/]*\$::p" "${PORTDIR}"/.ebuild.x \
      | uniq
}

Note that find_cat1() is case-insensitive, probably not what you want.

And without portage-utils' ebuilds cache, this works too:

find_cat3() {
   pushd "${PORTDIR}" >/dev/null
   ls -1d $(sed "s:\$:/${1}:" profiles/categories) 2>/dev/null
   popd >/dev/null
}

Here are some benchs (real time, with 1 run from cold I/O cache, and
then 100 runs also from cold I/O cache, with "fuse" as argument): 

 * find_cat1:
   - 0m0.972s
   - 0m25.967s
(No real advantage... that's not the primary target of this applet.)

 * find_cat2:
   - 0m0.237s
   - 0m3.746s
(Acceptable in both cases.)

 * find_cat3:
   - 0m2.319s
   - 0m2.607s
(Really slow on first run, but really fast once the tree as been
walked.  May be a good choice in some contexts.)

-- 
TGL.
-- 
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