#!/usr/bin/env python2.4
#
# $Id: findinactive.py,v 1.2 2006/02/20 16:39:56 jschauma Exp $
#
# mighty assumptions:
#   an account is inactive if a user has not accessed or modified any files
#   since 'cutoff'
#
#   every subdirectory under /home is that of a user
#
#
# defaults:
#  /home
#  cutoff date = today - 1 year
#  exclude files: none
#
# cutoff-date given ?
# exclude files given ?

import getopt
import os
import pwd
import time
import re
import string
import sys

EXIT_ERROR = 1
EXIT_SUCCESS = 0

HOMEROOT = "/home"
TODAY = time.time()
CUTOFFDIFF = 31556926
CUTOFFDATE = 0

def usage(val=0):
    print 'Usage: %s [-c|--cutoff] [-h|--help] [-r|--root]' % sys.argv[0]
    print '\t-c,--cutoff <date>\tspecify cutoff date in format [0-9]+[smhdMY]'
    print '\t-h,--help         \tshow this help and exit'
    print '\t-r,--root <dir>   \tspecify parent of users\' $HOME (default: /home)'
    sys.exit(val)

def init():
    """initializes all required variables"""

    global CUTOFFDATE

    CUTOFFDATE = (TODAY - CUTOFFDIFF)

def parseDate(date):
    """parse a given date and turn it into seconds since epoch"""

    last = date[-1]
    val = date[:-1]

    if not re.match('^[smhdMY]$', last):
        raise TypeError
    if not re.match('^[0-9]+$', val):
        raise TypeError

    rval = string.atoi(val)

    if last == "s":
        return rval
    elif last == "m":
        return (rval * 60)
    elif last == "h":
        return (rval * 60 * 60)
    elif last == "d":
        return (rval * 60 * 60 * 24)
    elif last == "M":
        return (rval * 60 * 60 * 24 * 30)
    elif last == "Y":
        return (rval * 60 * 60 * 24 * 30 * 12)


def parseOpts():
    global HOMEROOT
    global CUTOFFDATE
    global CUTOFFDIFF

    try:
        opts, args = getopt.getopt(sys.argv[1:],
                                    "c:hr:",
                                    ["cutoff", "help", "root"])
    except getopt.GetoptError:
        usage(EXIT_ERROR)

    for o, a in opts:
        if o in ("-c", "--cutoff"):
            try:
                CUTOFFDIFF = parseDate(a)
                CUTOFFDATE = (TODAY - CUTOFFDIFF)
            except TypeError:
                print '%s: invalid date given (\'%s\')' % (sys.argv[0], a)
                print
                usage(EXIT_ERROR)
        if o in ("-h", "--help"):
            usage()
        if o in ("-r", "--root"):
            HOMEROOT = a

def processHomeDir(uname, dirname, fnames):

    for f in fnames:
        path = os.path.join(dirname, f)
        sb = os.stat(path)
        # traversing the directory accesses it, so ignore
        if os.path.isdir(path):
            continue
        if sb.st_mtime > CUTOFFDATE or sb.st_atime > CUTOFFDATE:
            raise StopIteration

def main():
    global HOMEROOT
    users = []

    for entry in os.listdir(HOMEROOT):
        try:
            uid = pwd.getpwnam(entry)
            homeDir = os.path.join(HOMEROOT, entry)
            try:
                os.path.walk(homeDir, processHomeDir, entry)
                users.append(entry)
            except StopIteration:
                pass

        except KeyError:
            print 'no such user %s' % entry

    for u in users:
        print 'inactive: %s' % u
    return

def cleanup():
    return


if __name__ == "__main__":
    init()
    parseOpts()
    main()
    cleanup()