add vnu --help (#84)

html5validator/cli.py

@@ -35,9 +35,20 @@ def parse_yaml(filename, starter):
 
 def main():
     """Main function of html5validator"""
+    vnu_help, _ = Validator().run_vnu(['--help'])
+
     parser = argparse.ArgumentParser(
         description='[v' + VERSION + '] ' + __doc__,
-        prog='html5validator'
+        prog='html5validator',
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog='''
+
+This html5validator uses vnu.jar to check the files.
+It has many options that are documented in the
+vnu.jar help below.
+
+================= VNU help ========================
+        ''' + vnu_help,
     )
     parser.add_argument('files', nargs='*', default=None,
                         help='specify files to check')

html5validator/validator.py

@@ -138,15 +138,11 @@ def _vnu_options(self):
 
         return vnu_options
 
-    def validate(self, files):
-        if sys.platform == 'cygwin':
-            files = [_cygwin_path_convert(f) for f in files]
-
+    def run_vnu(self, arguments):
         try:
             cmd = (['java'] + self._java_options()
                    + ['-jar', self.vnu_jar_location]
-                   + self._vnu_options()
-                   + files)
+                   + arguments)
             LOGGER.debug(cmd)
             p = subprocess.Popen(
                 cmd,
@@ -162,9 +158,17 @@ def validate(self, files):
         except subprocess.CalledProcessError as error:
             raise (error.output.decode('utf-8'))
 
+        return stdout.decode('utf-8'), stderr.decode('utf-8')
+
+    def validate(self, files):
+        if sys.platform == 'cygwin':
+            files = [_cygwin_path_convert(f) for f in files]
+
+        stdout, stderr = self.run_vnu(self._vnu_options() + files)
+
         # process fancy quotes into standard quotes
-        stdout = _normalize_string(stdout.decode('utf-8'))
-        stderr = _normalize_string(stderr.decode('utf-8'))
+        stdout = _normalize_string(stdout)
+        stderr = _normalize_string(stderr)
 
         err = stdout.splitlines() + stderr.splitlines()