Add --version command line option (#4)

CHANGES.rst

@@ -5,7 +5,8 @@ Change log
 4.0.2 (unreleased)
 ==================
 
-- TBD
+- Add ``--version`` command line option (fixes
+  https://github.com/zopefoundation/zdaemon/issues/4).
 
 4.0.1 (2014-12-26)
 ==================

setup.py

@@ -46,7 +46,7 @@ def alltests():
         zip_safe=False,
         entry_points=entry_points,
         include_package_data = True,
-        install_requires=["ZConfig"],
+        install_requires=["ZConfig", "setuptools"],
         extras_require=dict(test=tests_require),
         test_suite='__main__.alltests',
         tests_require=tests_require

src/zdaemon/tests/testzdoptions.py

@@ -47,14 +47,14 @@ def restore_streams(self):
         sys.stdout = self.save_stdout
         sys.stderr = self.save_stderr
 
-    def check_exit_code(self, options, args):
+    def check_exit_code(self, options, args, exit_code=2):
         save_sys_stderr = sys.stderr
         try:
             sys.stderr = StringIO()
             try:
                 options.realize(args)
             except SystemExit as err:
-                self.assertEqual(err.code, 2)
+                self.assertEqual(err.code, exit_code)
             else:
                 self.fail("SystemExit expected")
         finally:
@@ -157,6 +157,16 @@ class HasHelp(self.OptionsClass):
             __doc__ = 'Some help'
         self.help_test_helper(HasHelp, {'doc': 'Example help'}, 'Example help')
 
+    def test_version(self):
+        options = self.OptionsClass()
+        options.version = '2.4.frog-knows'
+        self.save_streams()
+        try:
+            self.check_exit_code(options, ['--version'], exit_code=0)
+        finally:
+            self.restore_streams()
+        self.assertNotEqual(self.stdout.getvalue(), "2.4.frog-knows")
+
     def test_unrecognized(self):
         # Check that we get an error for an unrecognized option
         self.check_exit_code(self.OptionsClass(), ["-/"])

src/zdaemon/zdctl.py

@@ -32,6 +32,7 @@
 -u/--user USER -- run as this user (or numeric uid)
 -m/--umask UMASK -- use this umask for daemon subprocess (default is 022)
 -x/--exit-codes LIST -- list of fatal exit codes (default "0,2")
+--version -- print zdaemon version and exit
 -z/--directory DIRECTORY -- directory to chdir to when using -d (default off)
 action [arguments] -- see below
 

src/zdaemon/zdoptions.py

@@ -17,8 +17,10 @@
 import sys
 import getopt
 
+import pkg_resources
 import ZConfig
 
+
 class ZDOptions:
     """a zdaemon script.
 
@@ -27,6 +29,7 @@ class ZDOptions:
     Options:
     -C/--configure URL -- configuration file or URL
     -h/--help -- print usage message and exit
+    --version -- print zdaemon version and exit
 
     Actions are commands like "start", "stop" and "status".  If -i is
     specified or no action is specified on the command line, a "shell"
@@ -63,10 +66,17 @@ def __init__(self):
         self.required_map = {}
         self.environ_map = {}
         self.zconfig_options = []
+        self.version = pkg_resources.get_distribution("zdaemon").version
         self.add(None, None, "h", "help", self.help)
+        self.add(None, None, None, "version", self.print_version)
         self.add("configfile", None, "C:", "configure=")
         self.add(None, None, "X:", handler=self.zconfig_options.append)
 
+    def print_version(self, dummy):
+        """Print zdaemon version number to stdout and exit(0)."""
+        print(self.version)
+        sys.exit(0)
+
     def help(self, dummy):
         """Print a long help message (self.doc) to stdout and exit(0).