Re: [gentoo-dev] euses(1) Reimplementation

[Fabian Groffen]

Hi Ashley,

Sounds like you've put some work into this.  You could compare against
`quse -D <flag>` (from portage-utils) as well to get another point of
measure.

I don't know what you did measure euses against though, it seems fairly
fast to me (env PORTDIR=`q -e PORTDIR` euses -v libressl), is there a
specific case you're focussing on?

Thanks,
Fabian


On 09-07-2020 02:33:28 +0100, Ashley Dixon wrote:
> Hi, Gentoo-Dev.
>
> A while ago, I had a bit of a rant on Gentoo-User regarding the  current  issues
> with `app-portage/euses`.  Specifically, the fact that it does not work on newer
> Gentoo-like systems which have moved  away  from  PORTDIR  and  conform  to  the
> repos.conf/ syntax [1, 2, 3].  There are also some bugs/issues in the code, such
> as malloc(3)'ing without checking the result, et cetera.
>
> Over the past month or so, I've completed a ground-up rewrite which  provides  a
> similar interface and functionality, that remedies all of these issues, and adds
> a few useful features on  top;  it  is  also  written  in  standard  C  with  no
> dependencies other than the standard library.  In addition to processing all the
> repositories described in the repos.conf directory, it is  also  written  to  be
> remarkably robust, optionally working from the PORTDIR make.conf key-value  pair
> or environment variable for legacy systems.  (As an initial  user  pointed  out,
> make.conf cannot be used if it is a directory, and will only touched at  all  if
> the legacy option is enabled and the $PORTDIR environment variable is  unset  or
> infeasible.)
>
> Almost all of the features from the original euses tool are present, with extras
> to facilitate multi-repo searching (in the  rare  event  that  a  non-Gentoo.git
> repository has USE-description files).  From my testing, it is equally,  if  not
> more, performant than the original tool, despite the extra  work  of  traversing
> the meta-repository description files. A copy of the help page is included here,
> for convenience (run with the `-h` or `--help` option):
>
> ash-euses command-line argument summary.
> Syntax: ./ash-euses [options] substrings
>
> --list-repos    -r Prepend a list of located repositories (repos.conf/ only).
> --repo-names    -n Print repository names for each match.
> --repo-paths    -p Print repository details for each match (implies repo-names).
> --help          -h Print this help information and exit.
> --version       -v Prepend version and license information to the output.
> --strict        -s Search only in the flag field, excluding the description.
> --portdir       -d Attempt to use the PORTDIR value.
> --quiet         -q Do not complain about PORTDIR.
> --no-case       -c Perform a case-insensitive search across the files.
> --print-needles -e Prepend each match with the relevant needle substring.
> --no-interrupt  -i Do not interrupt the search results with warnings.
> --package       -k Restrict the search to category-package description files.
> --colour        -o Print the package, flag, and description in distinct colours.
> --                 Consider all further arguments as substrings/queries.
>
> There's also a man page in the tree, providing  deeper  explanations  for  these
> command-line arguments: `ash-euses.1`.
>
> Off-line, I'm working on a strstr(3) (and strcasestr) reimplementation using the
> Two-Way string-matching algorithm [4] and shift tables, to remove the dependency
> on _GNU_SOURCE for the case-insensitive variant (it is very annoying  that  this
> is not a standard function, as it only defines CANON_ELEMENT to  tolower(3)  and
> calls glibc strstr [5]).
>
> For all my tests, the search yield is generally identical to euses(1). An ebuild
> is also included in the tree, however I am hardly experienced with writing them,
> so I'm not entirely sure if it respects the  globally  defined  compiler  flags.
> Regardless, I am posting here for anyone who is interested in using/testing this
> program, with the hope that it can provide an alternative for quick  flag-lookup
> on newer, standards-conformant Gentoo-like systems.
>
> The source code is at [6], and a gzipped tarball of the  latest  release  (v0.3)
> can be found at [7]. Thank you in advance to all interested parties.
>
>         Cheers,
>         Ashley.
>
> P.S.  I really need a better name for this.  A portmanteau of my first name, and
> the tool of which the program is a replica, doesn't seem very creative.
>
> [1] https://bugs.gentoo.org/546210
> [2] https://bugs.gentoo.org/378603
> [3] https://bugs.gentoo.org/663706#c4
> [4] https://dl.acm.org/doi/abs/10.1145/116825.116845
> [5] https://sourceware.org/git/?p=glibc.git;a=blob;f=string/strcasestr.c;h=d2964c5548b9ea7a68fc5b18b25ddfe7ddd6835c;hb=HEAD#l45
> [6] http://git.suugaku.co.uk/ash-euses/tree/
> [7] http://git.suugaku.co.uk/ash-euses/snapshot/ash-euses-0.3.tar.gz
>
> --
>
> Ashley Dixon
> suugaku.co.uk
>
> 2A9A 4117
> DA96 D18A
> 8A7B B0D2
> A30E BF25
> F290 A8AA
>



-- 
Fabian Groffen
Gentoo on a different level