Move subs.xml and last.txt into configs dir

New runtime option allows specifying an optional config directory in
which the two required configuration files will be stored. It is useful
to make this directory a mounted volume when running in a docker
container.

dl.py

@@ -29,24 +29,37 @@ if __name__ == '__main__':
                         dest='since',
                         default=None,
                         help='Only download videos newer than the given number of days.')
+    parser.add_argument('--config-directory', '-f',
+                        dest='config',
+                        default=None,
+                        help='The directory to which config is saved.')
 
     args = parser.parse_args()
 
     # The current run time.
     script_time = time()
 
-    outlines = opml.parse('subs.xml')
+    subsPath = 'subs.xml'
+    if args.config is not None:
+        subsPath = f'{args.config}/{subsPath}'
+    outlines = opml.parse(subsPath)
 
     if args.output is not None:
         args.output = Path(args.output).absolute()
         os.chdir(args.output)
+    else:
+        print('Must specify an ouput directory with -o')
 
-    if not Path('last.txt').exists():
+    lastPath = 'last.txt'
-        with open('last.txt', 'w') as f:
+    if args.config is not None:
+        lastPath = f'{args.config}/{lastPath}'
+
+    if not Path(lastPath).exists():
+        with open(lastPath, 'w') as f:
             f.write(str(time()))
             print('Initialized a last.txt file with current timestamp.')
     else:
-        with open('last.txt', 'r') as f:
+        with open(lastPath, 'r') as f:
             # The last run time.
             threshold_time = datetime.utcfromtimestamp(float(f.read()))
 
@@ -66,9 +79,9 @@ if __name__ == '__main__':
                 if modified_time < keep_time:
                     print(f'Removing {str(video)}.')
                     video.unlink()
-    
+
         urls = [outline.xmlUrl for outline in outlines[0]]
-    
+
         videos = []
         for i, url in enumerate(urls):
             print(f'Parsing through channel {i + 1} of {len(urls)}', end='\r')
@@ -81,13 +94,14 @@ if __name__ == '__main__':
         print(' ' * 100, end='\r')
         if len(videos) == 0:
             print('Sorry, no new video found')
+            quit()
         else:
             print(f'{len(videos)} new videos found')
-    
+
         ydl_opts = {'ignoreerrors': True, 'quiet': True, 'outtmpl': (args.output / Path('%(uploader)s', '%(title)s.%(ext)s')).as_posix()}
-    
+
         with youtube_dl.YoutubeDL(ydl_opts) as ydl:
             ydl.download(videos)
-    
+
-        with open('last.txt', 'w') as f:
+        with open(lastPath, 'w') as f:
             f.write(str(script_time))