#!/usr/bin/env python

#
# gentoo-slotcheck.py
# Author: CJ Kucera <pez@apocalyptech.com>
# URL: http://apocalyptech.com/software/gentoo
#
# This script is designed to help clean up your Gentoo package
# installation database.  Portage has a concept of SLOTs that
# enable different versions of packages to exist side-by-side.
# More information on SLOTs can be found at:
#       http://gentoo.org/doc/portage-manual.html
#
# The early "skeleton" ebuild file, upon which many ebuilds were
# written, did not have a default SLOT defined, or it was blank.
# As ebuilds were revised, SLOT values were put in, but because
# the original versions had a blank SLOT, the newer versions
# existed side-by-side with the previous versions.  For instance,
# on my machine right now, I've got app-admin/chkrootkit version
# 0.35 and version 0.36.  0.35 has a blank SLOT, whereas 0.36
# has a SLOT of zero.  There's no reason to keep around the
# older version, but there it will sit until manually removed.
# Doing an "emerge clean" has no effect on SLOT-less packages.
#
# It should be noted that these extra versions really aren't
# that big of a deal, because "side-by-side" in this case
# is fairly meaningless; the new version is installed basically
# on top of the old version.  Still, old libraries can be kept
# around, stray files CAN cause confusion, and if you're a
# system-organizing freak like me, it'll bug you.  But if you
# want to make sure that you don't break things, and the
# lingering versions don't bother you, then you can pretty
# much ignore this script.
#
# If you feel like cleaning up your Portage tree by hand, you
# can do so by glancing around inside /var/db/pkg, but this
# script is designed to make it a bit easier.  It will scan
# through that directory and notice any program that's
# installed twice.  If one of those installations has a blank
# SLOT defined, it'll ask you if you'd like to remove that
# version.  If you say yes, it will first show you everything
# that depends on the program you're about to destroy (just
# so you're extra careful here), and also the output of
# "emerge --pretend unmerge <package>", so that you know what's
# about to happen to your system.  If you're okay with what
# was displayed, say Yes again, and it'll do the work for you.
#
# Note that while this program SHOULDN'T do anything nasty to
# your system, there's a chance that it'll erase your hard
# drive, fry your CPU, poison your cat, default your mortgage,
# promote racial hatred, and cause our sun to implode in on
# itself.  If you're uncomfortable about removing some package,
# then don't.  Again, it's typically not that big of a deal.
# Use with care and caution, and I'M NOT RESPONSIBLE!
#
# I'll hereby release this thing under the GPL, in case anyone
# cares.  See http://www.gnu.org/licenses/gpl.txt for details.
#
# Lastly, if anyone deems this script worthy of improvement,
# go for it.  It could certainly use some.  :)
#
# Version History:
#    2002.09.13 - CJ Kucera <pez@apocalyptech.com>
#                 Initial release
#    2002.09.13 - CJ Kucera <pez@apocalyptech.com>
#                 Consolidated a couple of loops (minor)
#
# TODO:
#  * Seeing as "emerge" is written in Python, it would probably
#    make sense to just call its functions in here, instead of
#    spawning off a new Python process.
#  * I'm aware that system() is far less secure than exec*()
#    or spawn*() or any other function that more rigidly defines
#    argument input.
#

import os,sys,portage

installcache = portage.db["/"]["vartree"]
for package in installcache.getallnodes():
  versions = installcache.getnode(package)
  if (len(versions) > 1):
    blankslots=[]
    totalversions=[]
    for version in versions:
      slot = installcache.getslot(version[0])
      version.append(slot)
      if (slot == ""):
        blankslots.append(version[0])
    if (len(blankslots) > 0):
      print "------------------------"
      print
      print "Package " + package + " has a SLOT mismatch:"
      print
      for version in versions:
        print " * " + version[0] + " has a SLOT of '" + version[2] + "'"
      print
      print "The following versions will be unmerged:"
      print
      unmergelist = ""
      for blank in blankslots:
        print " * " + blank
        unmergelist = unmergelist + blank + " "
      print
      sys.stdout.write("Do the unmerge [N/y/q]? ")
      dounmerge = sys.stdin.readline()
      print
      if (dounmerge[0].lower() == "y"):
        print "First we'll check qpkg and --pretend to make sure things are kosher . . ."
        print
        os.system("qpkg -q " + unmergelist)
        print
        os.system("emerge --pretend unmerge " + unmergelist)
        print
        sys.stdout.write("Still do the unmerge [N/y/q]? ")
        dounmerge = sys.stdin.readline()
        print
        if (dounmerge[0].lower() == "y"):
          print "Okay, here we go."
          os.system("emerge unmerge " + unmergelist)
        elif (dounmerge[0].lower() == "q"):
          sys.exit()
        else:
          print "Maybe next time, then."
      elif (dounmerge[0].lower() == "q"):
        sys.exit()
      else:
        print "We'll skip that one for now, then."
      print

# The End