a python implementation of pacman -Rs for groups

sweiss · 2005-06-24 14:30:36

I've created a simple python script which implements the pacman -Rs feature for package groups.

Here's the code:

#!/usr/bin/python

# Copyright (C) 2005 Shahar Weiss <sweiss4@gmx.net>
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#

# This script is a wrap for pacman which allows for removing package groups using the -Rs flag.
# It works by checking which packages of the group were explicitly installed and makes sure these packages are not
# needed by any other out-of-group packages. It then uses pacman and it's -Rs feature to remove the remaining packages
# in the list.

# Version 0.0.4

import os, sys

def returnIndex(_list, _string):
    """Returns the index in _list which contains _string, returns -1 is _string was not found"""
    for i in range(len(_list)):
        if _list[i].find(_string)!=-1:
            return i
            
    return -1

def removeRequiredForOtherPackages(packageList):
    """Returns a list of all the packages which are not required for other packages meant for removal."""
    tempList = packageList[:]
    for i in range(len(packageList)):
        Output = os.popen('pacman -Qi ' + packageList[i]).readlines()
        
        startIndex = returnIndex(Output, 'Required By')
        stopIndex = returnIndex(Output, 'Conflicts With')
        
        requiredList = Output[startIndex:stopIndex]
        
        tempReqList = requiredList[0].split(' ')
        for j in range(1,len(requiredList)):
            tempReqList.extend( requiredList[j].split(' '))
            
        requiredList = tempReqList[:]
        
        # Cleans requiredList from unneeded strings
        removeAllStrings(requiredList, '')
        removeAllStrings(requiredList, 'n')
        requiredList = requiredList[3:]
        
        if requiredList==['Nonen']:
            continue
        else:
            for j in range(len(requiredList)):
                # if there are packages who require the current package, check if they are enlisted for removal.
                # if not, then remove the current package from the list
                if requiredList[j] not in tempList:
                    tempList.remove( packageList[i] )
                    break                  
        
    return tempList

def removeNonExplicit(packageList):
    """Returns a list of all the packages which were explicitly installed."""
    # Creating a temporary list because removing an element from the original list instead
    # might cause us going out of bounds in the loop.
    tempList = packageList[:]
    for i in range(len(packageList)):
        packageInfoString = os.popen('pacman -Qi ' + packageList[i]).readlines()[11]
        
        # if the package was not explicitly installed, remove it from the list
        if packageInfoString.find('explicitly installed')==-1:
            tempList.remove(packageList[i])
    
    return tempList

def removeAllStrings(_list, _string):
    """Removes all instances of given _string from _list"""
    while _string in _list:
        _list.remove(_string)

def getGroupPackages(group_name):
    """Returns a list of the packages contained by a certain group"""
    tempList = os.popen('pacman -Qg ' + group_name + ' 2>/dev/null').readlines()
    
    # if there's no such group, quit.
    if tempList==['n']:
        print "No such group exists."
        sys.exit(1)
       
    packageList = []
    for i in range(len(tempList)):
        # Each element in tempList contains a string in the form of 'group packagen'.
        # The parsing we do adds only the 'package' part to packageList.
        packageList.append( tempList[i].split(' ')[1].split('n')[0] )
    
    return packageList
    
def main(args):
    if os.getuid()!=0:
        print "This program should be run as root."
        sys.exit(1)
    
    if len(args)==1:
        print "You did not provide a group for removal."
        sys.exit(1)
    
    packagesToRemove = getGroupPackages(args[-1])
    packagesToRemove = removeNonExplicit(packagesToRemove)
    packagesToRemove = removeRequiredForOtherPackages(packagesToRemove)
    
    if packagesToRemove==[]:
        print "No package was marked for removal."
        sys.exit(1)
    
    packageRemoveString=''
    for i in range(len(packagesToRemove)):
        packageRemoveString += packagesToRemove[i] + ' '
        
    os.system('pacman -Rs ' + packageRemoveString)
    
if __name__=="__main__":
    main(sys.argv)

Hope you like it and that it works well.
Enjoy.

Dusty · 2005-06-24 14:45:22

If you like, you could put this in the scripts section of the wiki:

http://wiki2.archlinux.org/index.php/Scripts

Dusty

sweiss · 2005-06-24 15:07:43

Will do. I've just added some error handling lines, gotta love rapid development.

EDIT: Done. Never used a wiki before, very nice system.

Dusty · 2005-06-24 15:13:15

sweiss wrote:

gotta love rapid development.

You mean 'gotta love Python' :-)

Dusty

sweiss · 2005-06-24 15:25:16

Synonyms, go figure

cactus · 2005-06-24 18:20:28

You might check out xerxes' libpypac. It does most of the pacman functions in python. Also, libpysrc does most of the makepkg functionality in python.

sweiss · 2005-06-24 21:04:19

Well I only lacked this feature in pacman so far, and I get a good python practice on the way.

I'll give libpypac a look though, thank you.

sweiss · 2005-07-18 07:26:17

Changed the code a bit so that no segfault of pacman is triggered during the process.

Arch Linux

#1 2005-06-24 14:30:36

a python implementation of pacman -Rs for groups

#2 2005-06-24 14:45:22

Re: a python implementation of pacman -Rs for groups

#3 2005-06-24 15:07:43

Re: a python implementation of pacman -Rs for groups

#4 2005-06-24 15:13:15

Re: a python implementation of pacman -Rs for groups

#5 2005-06-24 15:25:16

Re: a python implementation of pacman -Rs for groups

#6 2005-06-24 18:20:28

Re: a python implementation of pacman -Rs for groups

#7 2005-06-24 21:04:19

Re: a python implementation of pacman -Rs for groups

#8 2005-07-18 07:26:17

Re: a python implementation of pacman -Rs for groups

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