add dash-dash-version-cli-flag

"--version"

pysollib/init.py

@@ -79,6 +79,10 @@ def init():
             pysollib.settings.DEBUG = 1
         print(('PySol debugging: set DEBUG to', pysollib.settings.DEBUG))
 
+    if '--version' in sys.argv:
+        print("PySol FC version {}".format(pysollib.settings.VERSION))
+        sys.exit(0)
+
     # init toolkit
     if '--gtk' in sys.argv:
         pysollib.settings.TOOLKIT = 'gtk'

tests/lib/pysol_tests/test_version_flag.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+#
+# Copyright © 2022 Shlomi Fish <shlomif@cpan.org>
+#
+# Written by Shlomi Fish, under the MIT Expat License.
+
+import os
+import re
+import subprocess
+import unittest
+
+
+class CliFlagsTests(unittest.TestCase):
+    def test_main(self):
+        if os.name == 'nt':
+            self.assertTrue(True)
+            return
+        o = subprocess.check_output(["./pysol.py", "--version", ])
+        assert o
+        string = o.decode('utf-8')
+        self.assertTrue(re.match("\\APySol FC version [0-9]+\\.", string))