cryptedit: transparently edit GPG encrypted text file

cryptedit

#!/usr/bin/env python

# cryptedit: transparently edit GPG encrypted text file
#
# usage:
# - create an encrypted text file:
#       gpg -o text.gpg --symmetric text
# - edit it with cryptedit
#       cryptedit text.gpg

# Replace by your preferred editor
edit = 'gedit --standalone \'%s\''

import getpass
import os
import shutil
import sys
import tempfile

def check(result):
        if result != 0:
                print('aborting')
                raise SystemExit

encrypt = 'gpg --batch --yes --passphrase \'%s\' --output \'%s\' --symmetric \'%s\''
decrypt = 'gpg --batch --yes --passphrase \'%s\' --output \'%s\' --decrypt \'%s\''

try:
        encrypted = sys.argv[1]
except:
        print('Usage: %s <file>' % sys.argv[0])
        raise SystemExit

old = encrypted + '.old'
tmp = tempfile.mkstemp(prefix=encrypted+'.')
decrypted = tmp[1]
password = getpass.getpass()

check(os.system(decrypt % (password, decrypted, encrypted)))
time1 = os.stat(decrypted).st_mtime
check(os.system(edit % decrypted))
time2 = os.stat(decrypted).st_mtime
if time1 == time2:
        print('unchanged')
        raise SystemExit

shutil.copy2(encrypted, old)
check(os.system(encrypt % (password, encrypted, decrypted)))
os.close(tmp[0])
os.unlink(decrypted)