#!/usr/bin/env python

import os.path, re, subprocess, sys

def mntent_unescape(x):
    def replacement(m):
        unescapes = {
            "\\\\" : "\\",
            "\\011" : "\t",
            "\\012" : "\n",
            "\\040" : " "
        }
        return unescapes.get(m.group(0))
    return re.sub(r'(\\\\|\\011|\\012|\\040)', replacement, x)

targets = sys.argv[1:]
exit_status = 0
for target in targets:
    if not os.path.isdir(target):
        print >> sys.stderr, target, 'is not a directory'
        exit_status = 1
        continue
    top = os.path.realpath(target)
    proc_mounts = open('/proc/mounts', 'r')
    for line in proc_mounts:
        _, point, _ = line.split(' ', 2)
        point = mntent_unescape(point)
        if top == point or os.path.commonprefix((top + '/', point)) == top + '/':
            if subprocess.call(['umount', point]) != 0:
                exit_status = 1

sys.exit(exit_status)