py3: decode username and password before SMTP login
smtplib.SMTP.login() requires str on Python 3.
For 'password', we only need to decode when value comes from config as
getpass() returns the correct type already.
#!/usr/bin/env python
from __future__ import absolute_import, print_function
import errno
import os
import sys
for f in sys.argv[1:]:
try:
print(f, '->', os.readlink(f))
except OSError as err:
if err.errno != errno.EINVAL:
raise
print(f, '->', f, 'not a symlink')
sys.exit(0)