[youtube] Warn if URL is most likely wrong (#969)

[youtube-dl] / youtube_dl / extractor / youtube.py

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 96d8257d9093fe0892faefe18fd789b6ef207e5a..109c8a93fa9ca7cb4caeca87462e1385a802bb69 100644 (file)
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -168,7 +168,7 @@ class YoutubeIE(InfoExtractor):
         self.to_screen(u'RTMP download detected')
 
     def _decrypt_signature(self, s):
-        """Decrypt the key"""
+        """Turn the encrypted s field into a working signature"""
 
         if len(s) == 88:
             return s[48] + s[81:67:-1] + s[82] + s[66:62:-1] + s[85] + s[61:48:-1] + s[67] + s[47:12:-1] + s[3] + s[11:3:-1] + s[2] + s[12]
@@ -402,6 +402,9 @@ class YoutubeIE(InfoExtractor):
         return video_id
 
     def _real_extract(self, url):
+        if re.match(r'(?:https?://)?[^/]+/watch\?feature=[a-z_]+$', url):
+            self._downloader.report_warning(u'Did you forget to quote the URL? Remember that & is a meta-character in most shells, so you want to put the URL in quotes, like  youtube-dl \'http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc\' (or simply  youtube-dl BaW_jenozKc  ).')
+
         # Extract original video URL from URL with redirection, like age verification, using next_url parameter
         mobj = re.search(self._NEXT_URL_RE, url)
         if mobj: