ezumount - easily unmount and power off plugged USB disks from linux CLI

ezumount.py

#!/usr/bin/env python3
import os
import sys
import subprocess as subp

if len(sys.argv) != 2:
    appname = sys.argv[0]
    print('%s - unmount USB directory and power it off' % appname, file=sys.stderr)
    print('Usage: %s <directory>' % appname, file=sys.stderr)
    sys.exit(-1)

lines = subp.getoutput('df').splitlines()[1:]
mountpt_to_dev_map = {}
for l in lines:
    device, _1, _2, _3, _4, mountdst = l.split()
    mountpt_to_dev_map[mountdst] = device

dstdir = os.path.abspath(sys.argv[1])
srcdev = mountpt_to_dev_map.get(dstdir)
if srcdev is None:
    print('Directory %s is not a mount point' % dstdir, file=sys.stderr)
    sys.exit(-1)
i = 0
while i<len(srcdev) and srcdev[-i-1].isdigit():
    i += 1

maindev = srcdev[:(len(srcdev)-i)]

all_mountpts = [m for m,d in mountpt_to_dev_map.items() if d.startswith(maindev)]

for m in all_mountpts:
    code, out = subp.getstatusoutput("sudo umount '%s'" % m)
    if out:
        print(out)
    if code != 0:
        print('Failed to unmount %s (%d)'%(m, code), file=sys.stderr)
        sys.exit(code)

code, out = subp.getstatusoutput("sudo udisksctl power-off -b '%s'" % maindev)
if out:
    print(out)
if code != 0:
    print('Failed to poweroff %s (%d)'%(maindev, code), file=sys.stderr)
sys.exit(code)