OVERVIEW

  File::AptFetch provides API for APT (Advanced Package Tool, that's the
  Debian package management system) methods.  APT methods aren't
  libraries, they are executables (placed, by default, in
  /var/lib/apt/methods).  So it's not XS (and can't be), F::AF forks. 
  However one doesn't need fork for each file or session.  The IPC is
  pipe (and can't be anything else).  As you can see there's a limit of
  number of methods available simultaneously posed by the maximum number
  of open filehandles (APT methods aren't that numerous anyway).

  The module is named File::AptFetch because it always fetches.  I think
  that's possible to develop a method that would bring away files, but,
  at present, there's none.  And I doubt there would be any.

  Further reading:

  File::AptFetch
      POD of the module.  Covers API and provides examples of intended
      usage.  (bug) It's underdeveloped yet.

  File::AptFetch::Cookbook
      Provides some useful, I believe, findings on each method behaviour
      and an overview, of my understanding, how that stuff works.  Look,
      APT methods API documentation is quite outdated.  Each method is
      undocumented completely.  (bug) My knowledge of APT methods is
      very irregular, so is F::AF::C.

RUN-TIME REQUIREMENTS

  Perl
      v.5.8.0 or later.  Look, v.5.6.2 is "woody".  Eight years ago. 
      You must be kidding.

  IO::Pipe
      Any version.  It's distributed with Perl itself.  In core since
      v.5.3.7, predates debian, BTW.

BUILD-TIME REQUIREMENTS

  Test::More
      Any version.  Should be distributed with Perl itself too.

BUILD-TIME CONFIGURATION

  *lib_method*
      That sets location of APT methods.  It's unrequired, it will be
      set any time APT configuration is sourced. 
      "_cache_configuration()" in File::AptFetch and
      "_uncache_configuration()" in File::AptFetch have more.

  *config_source*
      Required.  "ARRAY" ref that will be execed. 
      "_cache_configuration()" in File::AptFetch has more.

  *signal*
      Required.  Names a signal that will be sent to method.  "DESTROY"
      in File::AptFetch has more.

  *timeout*
  *tick*
      *(v0.0.8)* Required.  I've believed, that could stay hardcoded.  I
      was wrong.  "_read()" in File::AptFetch has more.

      *(v0.1.6)* These are closely related.  From now on, *timeout*
      keeps the same semantics as before (it's time to cut-off) but is
      handled differently.  F::AF object sleeped (literally) for time
      set.  Now it selects (with magic)in *tick*s.  (It's introduced for
      sake of F::AF::S.)

      Also.  Both must be naturals; They're in seconds; *tick* is
      supposed to be couple of seconds (default: 5sec); While *timeout*
      is supposed to be large enough (default: 2min) in respect to
      network introduced delays.

TEST-SUITE

  Two things should be tested in regard with F::AF:

  methods and structures
      I wouldn't say I'm happy with this part (t/void/*.t).  It's mostly
      a crash-type testing.  And a problem here is that I'm not
      completely sure what an input (from methods side) here could be.

  APT methods itself
      Only local methods are tested.  And *cdrom* method, among them, is
      no way touched.  Remote methods are missing from the test-suite. 
      This problem is easily fixable -- some kind Perlist could upload
      on CPAN some modules, in Test namespace, what would provide fake
      servers of http://, ftp://, rsh:// etc protocols.  Anyone?

  And one note.  F::AF is absolutely useles outside APT based world (I'm
  not about *.deb, I'm about APT).  Then t/file/*.t and t/copy/*.t skip
  completely.  Meanwhile t/void/*.t enables some cute workaround, that
  would provide all needed "apt-config(1)" functionality without that
  executable itself.  (Just in case on that platform there will be
  Debian some day.) But we still stay within POSIX world -- no future
  outside.

AVAILABILITY

  pure distribution
      <http://search.cpan.org/dist/File-AptFetch/>

  and debianization stuff too
      # TODO

  subversion (root)
      # TODO

BUGS

  please report here
      <http://rt.cpan.org/Public/Dist/Display.html?Name=File-AptFetch/>

  please don't report there
      # TODO

COPYRIGHT AND LICENSING

  *   Copyright 2009, 2010, 2014 by Eric Pozharski <whynot@cpan.org>

  *   AS-IS, NO-WARRANTY, HOPE-TO-BE-USEFUL

  *   GNU Lesser General Public License v3
      <http://www.gnu.org/licenses/lgpl.txt>