#!/usr/bin/python
# wreq.py - (WhatRequires package)
#           translate provides into package names
#
# Requires: rpm, python >= 2.3
#
# ------------------ example --------------------
#  $ wreq.py libglade2
#  $   libglade2-2.5.1-1 is required by:
#  $   beep-0.9.7-1
#  $   pygtk2-2.6.2-1
#
# Finding orphaned packages:
#  $ wreq $(rpm -qa) | grep ^\!\!

from os import path, putenv, popen
import sets, sys

Usage = "Usage:  %s package\n" % path.basename(sys.argv[0])

if not sys.argv[1:]:
    print Usage
    raise SystemExit

putenv('LC_ALL', 'C')

for args in sets.Set(sys.argv[1:]): # Remove duplicates from list
    requires  = []
    installed = []
    installed = popen('rpm -q %s' % args)
    for pkg in set(installed):
        pkg = pkg.strip()
        if pkg.find('not installed') != -1:
            print '%s' % pkg
            break
        for item in popen('rpm -q --provides %s' % pkg):
            if item.find('(') == -1:
                for b in popen('rpm -q --whatrequires %s' % item):
                    b = b.strip()
                    if b.startswith('no package') or b == pkg:
                        pass
                    else:
                        requires.append(b.strip())
        if requires == []:
            print "!! No package requires %s" % pkg
        else:
            requires.sort()
            requires = sets.Set(requires)
            print "%s is required by:" % pkg
            for item in requires:
                print "\033[31;1m%s\033[0m" % item