Add documentation about supported sites (Fixes #4503)

[youtube-dl] / youtube_dl / utils.py

diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 5e92bcc7114e5c6c58e7e073f7bb7cfe3f7d59fb..efbe64fb315dba92383f8b1053a80558f4a12d7b 100644 (file)
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -363,7 +363,7 @@ def encodeArgument(s):
     if not isinstance(s, compat_str):
         # Legacy code that uses byte strings
         # Uncomment the following line after fixing all post processors
-        #assert False, 'Internal error: %r should be of type %r, is %r' % (s, compat_str, type(s))
+        # assert False, 'Internal error: %r should be of type %r, is %r' % (s, compat_str, type(s))
         s = s.decode('ascii')
     return encodeFilename(s, True)
 
@@ -464,6 +464,13 @@ class ExtractorError(Exception):
         return ''.join(traceback.format_tb(self.traceback))
 
 
+class UnsupportedError(ExtractorError):
+    def __init__(self, url):
+        super(UnsupportedError, self).__init__(
+            'Unsupported URL: %s' % url, expected=True)
+        self.url = url
+
+
 class RegexNotFoundError(ExtractorError):
     """Error when a regex didn't match"""
     pass
@@ -1262,18 +1269,25 @@ def check_executable(exe, args=[]):
 
 
 def get_exe_version(exe, args=['--version'],
-                    version_re=r'version\s+([0-9._-a-zA-Z]+)',
-                    unrecognized='present'):
+                    version_re=None, unrecognized='present'):
     """ Returns the version of the specified executable,
     or False if the executable is not present """
     try:
-        out, err = subprocess.Popen(
+        out, _ = subprocess.Popen(
             [exe] + args,
             stdout=subprocess.PIPE, stderr=subprocess.STDOUT).communicate()
     except OSError:
         return False
-    firstline = out.partition(b'\n')[0].decode('ascii', 'ignore')
-    m = re.search(version_re, firstline)
+    if isinstance(out, bytes):  # Python 2.x
+        out = out.decode('ascii', 'ignore')
+    return detect_exe_version(out, version_re, unrecognized)
+
+
+def detect_exe_version(output, version_re=None, unrecognized='present'):
+    assert isinstance(output, compat_str)
+    if version_re is None:
+        version_re = r'version\s+([-0-9._a-zA-Z]+)'
+    m = re.search(version_re, output)
     if m:
         return m.group(1)
     else: