tests/readlink.py

test-gpg: start gpg-agent by gpg-connect-agent only if GnuPG v2.1+ detected

Danek Duvall found that gpg-connect-agent of GnuPG 2.0 never starts gpg-agent
daemon. The 2.1 way is documented as "gpg-coonect-agent /bye" [1], which
appears to be different from the 2.0 way [2].

 [1]: https://www.gnupg.org/documentation/manuals/gnupg/Invoking-GPG_002dAGENT.html
 [2]: https://www.gnupg.org/documentation/manuals/gnupg-2.0/Invoking-GPG_002dAGENT.html

Since "gpg-agent --daemon" of GnuPG 2.1 never prints environment variables,
"eval $(gpg-agent --daemon)" would be valid only for GnuPG < 2.1, and we'll
need a different workaround for 2.0. I have no 2.0 environment, I won't
implement it.

#!/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)