Add a --default-scheme argument.

httpie/cli.py

@@ -88,6 +88,7 @@ positional.add_argument(
     metavar='URL',
     help="""
     The scheme defaults to 'http://' if the URL does not include one.
+    (You can override this with: --default-scheme https)
 
     You can also use a shorthand for localhost
 
@@ -558,6 +559,15 @@ troubleshooting.add_argument(
 
     """
 )
+troubleshooting.add_argument(
+    '--default-scheme',
+    choices=["http", "https"],
+    default="http",
+    help="""
+    Default scheme to use if not specified in the URL.
+
+    """
+)
 troubleshooting.add_argument(
     '--debug',
     action='store_true',

httpie/input.py

@@ -137,7 +137,7 @@ class Parser(ArgumentParser):
         if not self.args.ignore_stdin and not env.stdin_isatty:
             self._body_from_file(self.env.stdin)
         if not URL_SCHEME_RE.match(self.args.url):
-            scheme = HTTP
+            scheme = self.args.default_scheme + "://"
 
             # See if we're using curl style shorthand for localhost (:3000/foo)
             shorthand = re.match(r'^:(?!:)(\d*)(/?.*)$', self.args.url)