]> Raphaƫl G. Git Repositories - youtubedl/blobdiff - youtube_dl/utils.py
Initiate a new release.
[youtubedl] / youtube_dl / utils.py
index 616948e1080d18352189a48c4967644f4e761b20..8f5463f1c9a1e1a2660867abdc0f1f62e9147032 100644 (file)
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+from __future__ import unicode_literals
+
+import calendar
+import codecs
+import contextlib
+import ctypes
+import datetime
+import email.utils
 import errno
+import functools
 import gzip
+import itertools
 import io
 import json
 import locale
+import math
 import os
+import pipes
+import platform
 import re
+import ssl
+import socket
+import struct
+import subprocess
 import sys
+import tempfile
 import traceback
+import xml.etree.ElementTree
 import zlib
-import email.utils
-import json
-import datetime
-
-try:
-    import urllib.request as compat_urllib_request
-except ImportError: # Python 2
-    import urllib2 as compat_urllib_request
-
-try:
-    import urllib.error as compat_urllib_error
-except ImportError: # Python 2
-    import urllib2 as compat_urllib_error
 
-try:
-    import urllib.parse as compat_urllib_parse
-except ImportError: # Python 2
-    import urllib as compat_urllib_parse
-
-try:
-    from urllib.parse import urlparse as compat_urllib_parse_urlparse
-except ImportError: # Python 2
-    from urlparse import urlparse as compat_urllib_parse_urlparse
-
-try:
-    import http.cookiejar as compat_cookiejar
-except ImportError: # Python 2
-    import cookielib as compat_cookiejar
-
-try:
-    import html.entities as compat_html_entities
-except ImportError: # Python 2
-    import htmlentitydefs as compat_html_entities
-
-try:
-    import html.parser as compat_html_parser
-except ImportError: # Python 2
-    import HTMLParser as compat_html_parser
-
-try:
-    import http.client as compat_http_client
-except ImportError: # Python 2
-    import httplib as compat_http_client
-
-try:
-    from subprocess import DEVNULL
-    compat_subprocess_get_DEVNULL = lambda: DEVNULL
-except ImportError:
-    compat_subprocess_get_DEVNULL = lambda: open(os.path.devnull, 'w')
-
-try:
-    from urllib.parse import parse_qs as compat_parse_qs
-except ImportError: # Python 2
-    # HACK: The following is the correct parse_qs implementation from cpython 3's stdlib.
-    # Python 2's version is apparently totally broken
-    def _unquote(string, encoding='utf-8', errors='replace'):
-        if string == '':
-            return string
-        res = string.split('%')
-        if len(res) == 1:
-            return string
-        if encoding is None:
-            encoding = 'utf-8'
-        if errors is None:
-            errors = 'replace'
-        # pct_sequence: contiguous sequence of percent-encoded bytes, decoded
-        pct_sequence = b''
-        string = res[0]
-        for item in res[1:]:
-            try:
-                if not item:
-                    raise ValueError
-                pct_sequence += item[:2].decode('hex')
-                rest = item[2:]
-                if not rest:
-                    # This segment was just a single percent-encoded character.
-                    # May be part of a sequence of code units, so delay decoding.
-                    # (Stored in pct_sequence).
-                    continue
-            except ValueError:
-                rest = '%' + item
-            # Encountered non-percent-encoded characters. Flush the current
-            # pct_sequence.
-            string += pct_sequence.decode(encoding, errors) + rest
-            pct_sequence = b''
-        if pct_sequence:
-            # Flush the final pct_sequence
-            string += pct_sequence.decode(encoding, errors)
-        return string
-
-    def _parse_qsl(qs, keep_blank_values=False, strict_parsing=False,
-                encoding='utf-8', errors='replace'):
-        qs, _coerce_result = qs, unicode
-        pairs = [s2 for s1 in qs.split('&') for s2 in s1.split(';')]
-        r = []
-        for name_value in pairs:
-            if not name_value and not strict_parsing:
-                continue
-            nv = name_value.split('=', 1)
-            if len(nv) != 2:
-                if strict_parsing:
-                    raise ValueError("bad query field: %r" % (name_value,))
-                # Handle case of a control-name with no equal sign
-                if keep_blank_values:
-                    nv.append('')
-                else:
-                    continue
-            if len(nv[1]) or keep_blank_values:
-                name = nv[0].replace('+', ' ')
-                name = _unquote(name, encoding=encoding, errors=errors)
-                name = _coerce_result(name)
-                value = nv[1].replace('+', ' ')
-                value = _unquote(value, encoding=encoding, errors=errors)
-                value = _coerce_result(value)
-                r.append((name, value))
-        return r
-
-    def compat_parse_qs(qs, keep_blank_values=False, strict_parsing=False,
-                encoding='utf-8', errors='replace'):
-        parsed_result = {}
-        pairs = _parse_qsl(qs, keep_blank_values, strict_parsing,
-                        encoding=encoding, errors=errors)
-        for name, value in pairs:
-            if name in parsed_result:
-                parsed_result[name].append(value)
-            else:
-                parsed_result[name] = [value]
-        return parsed_result
-
-try:
-    compat_str = unicode # Python 2
-except NameError:
-    compat_str = str
-
-try:
-    compat_chr = unichr # Python 2
-except NameError:
-    compat_chr = chr
+from .compat import (
+    compat_basestring,
+    compat_chr,
+    compat_getenv,
+    compat_html_entities,
+    compat_http_client,
+    compat_parse_qs,
+    compat_socket_create_connection,
+    compat_str,
+    compat_urllib_error,
+    compat_urllib_parse,
+    compat_urllib_parse_urlparse,
+    compat_urllib_request,
+    compat_urlparse,
+    shlex_quote,
+)
+
+
+# This is not clearly defined otherwise
+compiled_regex_type = type(re.compile(''))
 
 std_headers = {
-    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20100101 Firefox/10.0',
+    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20100101 Firefox/10.0 (Chrome)',
     'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
     'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
     'Accept-Encoding': 'gzip, deflate',
     'Accept-Language': 'en-us,en;q=0.5',
 }
 
+
 def preferredencoding():
     """Get preferred encoding.
 
@@ -166,145 +69,150 @@ def preferredencoding():
     """
     try:
         pref = locale.getpreferredencoding()
-        u'TEST'.encode(pref)
+        'TEST'.encode(pref)
     except:
         pref = 'UTF-8'
 
     return pref
 
-if sys.version_info < (3,0):
-    def compat_print(s):
-        print(s.encode(preferredencoding(), 'xmlcharrefreplace'))
-else:
-    def compat_print(s):
-        assert type(s) == type(u'')
-        print(s)
-
-# In Python 2.x, json.dump expects a bytestream.
-# In Python 3.x, it writes to a character stream
-if sys.version_info < (3,0):
-    def write_json_file(obj, fn):
-        with open(fn, 'wb') as f:
-            json.dump(obj, f)
-else:
-    def write_json_file(obj, fn):
-        with open(fn, 'w', encoding='utf-8') as f:
-            json.dump(obj, f)
 
-def htmlentity_transform(matchobj):
-    """Transforms an HTML entity to a character.
+def write_json_file(obj, fn):
+    """ Encode obj as JSON and write it to fn, atomically if possible """
 
-    This function receives a match object and is intended to be used with
-    the re.sub() function.
-    """
-    entity = matchobj.group(1)
+    fn = encodeFilename(fn)
+    if sys.version_info < (3, 0) and sys.platform != 'win32':
+        encoding = get_filesystem_encoding()
+        # os.path.basename returns a bytes object, but NamedTemporaryFile
+        # will fail if the filename contains non ascii characters unless we
+        # use a unicode object
+        path_basename = lambda f: os.path.basename(fn).decode(encoding)
+        # the same for os.path.dirname
+        path_dirname = lambda f: os.path.dirname(fn).decode(encoding)
+    else:
+        path_basename = os.path.basename
+        path_dirname = os.path.dirname
+
+    args = {
+        'suffix': '.tmp',
+        'prefix': path_basename(fn) + '.',
+        'dir': path_dirname(fn),
+        'delete': False,
+    }
+
+    # In Python 2.x, json.dump expects a bytestream.
+    # In Python 3.x, it writes to a character stream
+    if sys.version_info < (3, 0):
+        args['mode'] = 'wb'
+    else:
+        args.update({
+            'mode': 'w',
+            'encoding': 'utf-8',
+        })
 
-    # Known non-numeric HTML entity
-    if entity in compat_html_entities.name2codepoint:
-        return compat_chr(compat_html_entities.name2codepoint[entity])
+    tf = tempfile.NamedTemporaryFile(**args)
 
-    mobj = re.match(u'(?u)#(x?\\d+)', entity)
-    if mobj is not None:
-        numstr = mobj.group(1)
-        if numstr.startswith(u'x'):
-            base = 16
-            numstr = u'0%s' % numstr
+    try:
+        with tf:
+            json.dump(obj, tf)
+        if sys.platform == 'win32':
+            # Need to remove existing file on Windows, else os.rename raises
+            # WindowsError or FileExistsError.
+            try:
+                os.unlink(fn)
+            except OSError:
+                pass
+        os.rename(tf.name, fn)
+    except:
+        try:
+            os.remove(tf.name)
+        except OSError:
+            pass
+        raise
+
+
+if sys.version_info >= (2, 7):
+    def find_xpath_attr(node, xpath, key, val):
+        """ Find the xpath xpath[@key=val] """
+        assert re.match(r'^[a-zA-Z-]+$', key)
+        assert re.match(r'^[a-zA-Z0-9@\s:._-]*$', val)
+        expr = xpath + "[@%s='%s']" % (key, val)
+        return node.find(expr)
+else:
+    def find_xpath_attr(node, xpath, key, val):
+        # Here comes the crazy part: In 2.6, if the xpath is a unicode,
+        # .//node does not match if a node is a direct child of . !
+        if isinstance(xpath, compat_str):
+            xpath = xpath.encode('ascii')
+
+        for f in node.findall(xpath):
+            if f.attrib.get(key) == val:
+                return f
+        return None
+
+# On python2.6 the xml.etree.ElementTree.Element methods don't support
+# the namespace parameter
+
+
+def xpath_with_ns(path, ns_map):
+    components = [c.split(':') for c in path.split('/')]
+    replaced = []
+    for c in components:
+        if len(c) == 1:
+            replaced.append(c[0])
         else:
-            base = 10
-        return compat_chr(int(numstr, base))
+            ns, tag = c
+            replaced.append('{%s}%s' % (ns_map[ns], tag))
+    return '/'.join(replaced)
 
-    # Unknown entity in name, return its literal representation
-    return (u'&%s;' % entity)
-
-compat_html_parser.locatestarttagend = re.compile(r"""<[a-zA-Z][-.a-zA-Z0-9:_]*(?:\s+(?:(?<=['"\s])[^\s/>][^\s/=>]*(?:\s*=+\s*(?:'[^']*'|"[^"]*"|(?!['"])[^>\s]*))?\s*)*)?\s*""", re.VERBOSE) # backport bugfix
-class AttrParser(compat_html_parser.HTMLParser):
-    """Modified HTMLParser that isolates a tag with the specified attribute"""
-    def __init__(self, attribute, value):
-        self.attribute = attribute
-        self.value = value
-        self.result = None
-        self.started = False
-        self.depth = {}
-        self.html = None
-        self.watch_startpos = False
-        self.error_count = 0
-        compat_html_parser.HTMLParser.__init__(self)
-
-    def error(self, message):
-        if self.error_count > 10 or self.started:
-            raise compat_html_parser.HTMLParseError(message, self.getpos())
-        self.rawdata = '\n'.join(self.html.split('\n')[self.getpos()[0]:]) # skip one line
-        self.error_count += 1
-        self.goahead(1)
-
-    def loads(self, html):
-        self.html = html
-        self.feed(html)
-        self.close()
-
-    def handle_starttag(self, tag, attrs):
-        attrs = dict(attrs)
-        if self.started:
-            self.find_startpos(None)
-        if self.attribute in attrs and attrs[self.attribute] == self.value:
-            self.result = [tag]
-            self.started = True
-            self.watch_startpos = True
-        if self.started:
-            if not tag in self.depth: self.depth[tag] = 0
-            self.depth[tag] += 1
-
-    def handle_endtag(self, tag):
-        if self.started:
-            if tag in self.depth: self.depth[tag] -= 1
-            if self.depth[self.result[0]] == 0:
-                self.started = False
-                self.result.append(self.getpos())
-
-    def find_startpos(self, x):
-        """Needed to put the start position of the result (self.result[1])
-        after the opening tag with the requested id"""
-        if self.watch_startpos:
-            self.watch_startpos = False
-            self.result.append(self.getpos())
-    handle_entityref = handle_charref = handle_data = handle_comment = \
-    handle_decl = handle_pi = unknown_decl = find_startpos
-
-    def get_result(self):
-        if self.result is None:
-            return None
-        if len(self.result) != 3:
+
+def xpath_text(node, xpath, name=None, fatal=False):
+    if sys.version_info < (2, 7):  # Crazy 2.6
+        xpath = xpath.encode('ascii')
+
+    n = node.find(xpath)
+    if n is None or n.text is None:
+        if fatal:
+            name = xpath if name is None else name
+            raise ExtractorError('Could not find XML element %s' % name)
+        else:
             return None
-        lines = self.html.split('\n')
-        lines = lines[self.result[1][0]-1:self.result[2][0]]
-        lines[0] = lines[0][self.result[1][1]:]
-        if len(lines) == 1:
-            lines[-1] = lines[-1][:self.result[2][1]-self.result[1][1]]
-        lines[-1] = lines[-1][:self.result[2][1]]
-        return '\n'.join(lines).strip()
-# Hack for https://github.com/rg3/youtube-dl/issues/662
-if sys.version_info < (2, 7, 3):
-    AttrParser.parse_endtag = (lambda self, i:
-        i + len("</scr'+'ipt>")
-        if self.rawdata[i:].startswith("</scr'+'ipt>")
-        else compat_html_parser.HTMLParser.parse_endtag(self, i))
+    return n.text
+
 
 def get_element_by_id(id, html):
     """Return the content of the tag with the specified ID in the passed HTML document"""
     return get_element_by_attribute("id", id, html)
 
+
 def get_element_by_attribute(attribute, value, html):
     """Return the content of the tag with the specified attribute in the passed HTML document"""
-    parser = AttrParser(attribute, value)
-    try:
-        parser.loads(html)
-    except compat_html_parser.HTMLParseError:
-        pass
-    return parser.get_result()
+
+    m = re.search(r'''(?xs)
+        <([a-zA-Z0-9:._-]+)
+         (?:\s+[a-zA-Z0-9:._-]+(?:=[a-zA-Z0-9:._-]+|="[^"]+"|='[^']+'))*?
+         \s+%s=['"]?%s['"]?
+         (?:\s+[a-zA-Z0-9:._-]+(?:=[a-zA-Z0-9:._-]+|="[^"]+"|='[^']+'))*?
+        \s*>
+        (?P<content>.*?)
+        </\1>
+    ''' % (re.escape(attribute), re.escape(value)), html)
+
+    if not m:
+        return None
+    res = m.group('content')
+
+    if res.startswith('"') or res.startswith("'"):
+        res = res[1:-1]
+
+    return unescapeHTML(res)
 
 
 def clean_html(html):
     """Clean an HTML snippet into a readable string"""
+
+    if html is None:  # Convenience for sanitizing descriptions etc.
+        return html
+
     # Newline vs <br />
     html = html.replace('\n', ' ')
     html = re.sub(r'\s*<\s*br\s*/?\s*>\s*', '\n', html)
@@ -327,7 +235,7 @@ def sanitize_open(filename, open_mode):
     It returns the tuple (stream, definitive_file_name).
     """
     try:
-        if filename == u'-':
+        if filename == '-':
             if sys.platform == 'win32':
                 import msvcrt
                 msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
@@ -340,9 +248,9 @@ def sanitize_open(filename, open_mode):
 
         # In case of error, try to remove win32 forbidden chars
         alt_filename = os.path.join(
-                        re.sub(u'[/<>:"\\|\\\\?\\*]', u'#', path_part)
-                        for path_part in os.path.split(filename)
-                       )
+            re.sub('[/<>:"\\|\\\\?\\*]', '#', path_part)
+            for path_part in os.path.split(filename)
+        )
         if alt_filename == filename:
             raise
         else:
@@ -359,6 +267,7 @@ def timeconvert(timestr):
         timestamp = email.utils.mktime_tz(timetuple)
     return timestamp
 
+
 def sanitize_filename(s, restricted=False, is_id=False):
     """Sanitizes a string so it could be used as part of a filename.
     If restricted is set, use a stricter subset of allowed characters.
@@ -379,7 +288,9 @@ def sanitize_filename(s, restricted=False, is_id=False):
             return '_'
         return char
 
-    result = u''.join(map(replace_insane, s))
+    # Handle timestamps
+    s = re.sub(r'[0-9]+(?::[0-9]+)+', lambda m: m.group(0).replace(':', '_'), s)
+    result = ''.join(map(replace_insane, s))
     if not is_id:
         while '__' in result:
             result = result.replace('__', '_')
@@ -391,6 +302,7 @@ def sanitize_filename(s, restricted=False, is_id=False):
             result = '_'
     return result
 
+
 def orderedSet(iterable):
     """ Remove all duplicates from the input iterable """
     res = []
@@ -399,36 +311,72 @@ def orderedSet(iterable):
             res.append(el)
     return res
 
+
+def _htmlentity_transform(entity):
+    """Transforms an HTML entity to a character."""
+    # Known non-numeric HTML entity
+    if entity in compat_html_entities.name2codepoint:
+        return compat_chr(compat_html_entities.name2codepoint[entity])
+
+    mobj = re.match(r'#(x?[0-9]+)', entity)
+    if mobj is not None:
+        numstr = mobj.group(1)
+        if numstr.startswith('x'):
+            base = 16
+            numstr = '0%s' % numstr
+        else:
+            base = 10
+        return compat_chr(int(numstr, base))
+
+    # Unknown entity in name, return its literal representation
+    return ('&%s;' % entity)
+
+
 def unescapeHTML(s):
-    """
-    @param s a string
-    """
-    assert type(s) == type(u'')
+    if s is None:
+        return None
+    assert type(s) == compat_str
+
+    return re.sub(
+        r'&([^;]+);', lambda m: _htmlentity_transform(m.group(1)), s)
 
-    result = re.sub(u'(?u)&(.+?);', htmlentity_transform, s)
-    return result
 
-def encodeFilename(s):
+def encodeFilename(s, for_subprocess=False):
     """
     @param s The name of the file
     """
 
-    assert type(s) == type(u'')
+    assert type(s) == compat_str
 
     # Python 3 has a Unicode API
     if sys.version_info >= (3, 0):
         return s
 
     if sys.platform == 'win32' and sys.getwindowsversion()[0] >= 5:
-        # Pass u'' directly to use Unicode APIs on Windows 2000 and up
+        # Pass '' directly to use Unicode APIs on Windows 2000 and up
         # (Detecting Windows NT 4 is tricky because 'major >= 4' would
         # match Windows 9x series as well. Besides, NT 4 is obsolete.)
-        return s
+        if not for_subprocess:
+            return s
+        else:
+            # For subprocess calls, encode with locale encoding
+            # Refer to http://stackoverflow.com/a/9951851/35070
+            encoding = preferredencoding()
     else:
         encoding = sys.getfilesystemencoding()
-        if encoding is None:
-            encoding = 'utf-8'
-        return s.encode(encoding, 'ignore')
+    if encoding is None:
+        encoding = 'utf-8'
+    return s.encode(encoding, 'ignore')
+
+
+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))
+        s = s.decode('ascii')
+    return encodeFilename(s, True)
+
 
 def decodeOption(optval):
     if optval is None:
@@ -439,6 +387,7 @@ def decodeOption(optval):
     assert isinstance(optval, compat_str)
     return optval
 
+
 def formatSeconds(secs):
     if secs > 3600:
         return '%d:%02d:%02d' % (secs // 3600, (secs % 3600) // 60, secs % 60)
@@ -447,32 +396,77 @@ def formatSeconds(secs):
     else:
         return '%d' % secs
 
-def make_HTTPS_handler(opts):
-    if sys.version_info < (3,2):
-        # Python's 2.x handler is very simplistic
-        return compat_urllib_request.HTTPSHandler()
-    else:
-        import ssl
-        context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
-        context.set_default_verify_paths()
-        
+
+def make_HTTPS_handler(params, **kwargs):
+    opts_no_check_certificate = params.get('nocheckcertificate', False)
+    if hasattr(ssl, 'create_default_context'):  # Python >= 3.4 or 2.7.9
+        context = ssl.create_default_context(ssl.Purpose.SERVER_AUTH)
+        if opts_no_check_certificate:
+            context.check_hostname = False
+            context.verify_mode = ssl.CERT_NONE
+        try:
+            return YoutubeDLHTTPSHandler(params, context=context, **kwargs)
+        except TypeError:
+            # Python 2.7.8
+            # (create_default_context present but HTTPSHandler has no context=)
+            pass
+
+    if sys.version_info < (3, 2):
+        return YoutubeDLHTTPSHandler(params, **kwargs)
+    else:  # Python < 3.4
+        context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
         context.verify_mode = (ssl.CERT_NONE
-                               if opts.no_check_certificate
+                               if opts_no_check_certificate
                                else ssl.CERT_REQUIRED)
-        return compat_urllib_request.HTTPSHandler(context=context)
+        context.set_default_verify_paths()
+        return YoutubeDLHTTPSHandler(params, context=context, **kwargs)
+
 
 class ExtractorError(Exception):
     """Error during info extraction."""
-    def __init__(self, msg, tb=None):
-        """ tb, if given, is the original traceback (so that it can be printed out). """
+
+    def __init__(self, msg, tb=None, expected=False, cause=None, video_id=None):
+        """ tb, if given, is the original traceback (so that it can be printed out).
+        If expected is set, this is a normal error message and most likely not a bug in youtube-dl.
+        """
+
+        if sys.exc_info()[0] in (compat_urllib_error.URLError, socket.timeout, UnavailableVideoError):
+            expected = True
+        if video_id is not None:
+            msg = video_id + ': ' + msg
+        if cause:
+            msg += ' (caused by %r)' % cause
+        if not expected:
+            if ytdl_is_updateable():
+                update_cmd = 'type  youtube-dl -U  to update'
+            else:
+                update_cmd = 'see  https://yt-dl.org/update  on how to update'
+            msg += '; please report this issue on https://yt-dl.org/bug .'
+            msg += ' Make sure you are using the latest version; %s.' % update_cmd
+            msg += ' Be sure to call youtube-dl with the --verbose flag and include its complete output.'
         super(ExtractorError, self).__init__(msg)
+
         self.traceback = tb
         self.exc_info = sys.exc_info()  # preserve original exception
+        self.cause = cause
+        self.video_id = video_id
 
     def format_traceback(self):
         if self.traceback is None:
             return None
-        return u''.join(traceback.format_tb(self.traceback))
+        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
 
 
 class DownloadError(Exception):
@@ -482,6 +476,7 @@ class DownloadError(Exception):
     configured to continue on errors. They will contain the appropriate
     error message.
     """
+
     def __init__(self, msg, exc_info=None):
         """ exc_info, if given, is the original exception that caused the trouble (as returned by sys.exc_info()). """
         super(DownloadError, self).__init__(msg)
@@ -503,9 +498,11 @@ class PostProcessingError(Exception):
     This exception may be raised by PostProcessor's .run() method to
     indicate an error in the postprocessing task.
     """
+
     def __init__(self, msg):
         self.msg = msg
 
+
 class MaxDownloadsReached(Exception):
     """ --max-downloads limit has been reached. """
     pass
@@ -535,6 +532,29 @@ class ContentTooShortError(Exception):
         self.downloaded = downloaded
         self.expected = expected
 
+
+def _create_http_connection(ydl_handler, http_class, is_https, *args, **kwargs):
+    hc = http_class(*args, **kwargs)
+    source_address = ydl_handler._params.get('source_address')
+    if source_address is not None:
+        sa = (source_address, 0)
+        if hasattr(hc, 'source_address'):  # Python 2.7+
+            hc.source_address = sa
+        else:  # Python 2.6
+            def _hc_connect(self, *args, **kwargs):
+                sock = compat_socket_create_connection(
+                    (self.host, self.port), self.timeout, sa)
+                if is_https:
+                    self.sock = ssl.wrap_socket(
+                        sock, self.key_file, self.cert_file,
+                        ssl_version=ssl.PROTOCOL_TLSv1)
+                else:
+                    self.sock = sock
+            hc.connect = functools.partial(_hc_connect, hc)
+
+    return hc
+
+
 class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
     """Handler for HTTP requests and responses.
 
@@ -553,6 +573,15 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
     public domain.
     """
 
+    def __init__(self, params, *args, **kwargs):
+        compat_urllib_request.HTTPHandler.__init__(self, *args, **kwargs)
+        self._params = params
+
+    def http_open(self, req):
+        return self.do_open(functools.partial(
+            _create_http_connection, self, compat_http_client.HTTPConnection, False),
+            req)
+
     @staticmethod
     def deflate(data):
         try:
@@ -569,27 +598,44 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
         return ret
 
     def http_request(self, req):
-        for h,v in std_headers.items():
-            if h in req.headers:
-                del req.headers[h]
-            req.add_header(h, v)
+        for h, v in std_headers.items():
+            # Capitalize is needed because of Python bug 2275: http://bugs.python.org/issue2275
+            # The dict keys are capitalized because of this bug by urllib
+            if h.capitalize() not in req.headers:
+                req.add_header(h, v)
         if 'Youtubedl-no-compression' in req.headers:
             if 'Accept-encoding' in req.headers:
                 del req.headers['Accept-encoding']
             del req.headers['Youtubedl-no-compression']
-        if 'Youtubedl-user-agent' in req.headers:
-            if 'User-agent' in req.headers:
-                del req.headers['User-agent']
-            req.headers['User-agent'] = req.headers['Youtubedl-user-agent']
-            del req.headers['Youtubedl-user-agent']
+
+        if sys.version_info < (2, 7) and '#' in req.get_full_url():
+            # Python 2.6 is brain-dead when it comes to fragments
+            req._Request__original = req._Request__original.partition('#')[0]
+            req._Request__r_type = req._Request__r_type.partition('#')[0]
+
         return req
 
     def http_response(self, req, resp):
         old_resp = resp
         # gzip
         if resp.headers.get('Content-encoding', '') == 'gzip':
-            gz = gzip.GzipFile(fileobj=io.BytesIO(resp.read()), mode='r')
-            resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
+            content = resp.read()
+            gz = gzip.GzipFile(fileobj=io.BytesIO(content), mode='rb')
+            try:
+                uncompressed = io.BytesIO(gz.read())
+            except IOError as original_ioerror:
+                # There may be junk add the end of the file
+                # See http://stackoverflow.com/q/4928560/35070 for details
+                for i in range(1, 1024):
+                    try:
+                        gz = gzip.GzipFile(fileobj=io.BytesIO(content[:-i]), mode='rb')
+                        uncompressed = io.BytesIO(gz.read())
+                    except IOError:
+                        continue
+                    break
+                else:
+                    raise original_ioerror
+            resp = self.addinfourl_wrapper(uncompressed, old_resp.headers, old_resp.url, old_resp.code)
             resp.msg = old_resp.msg
         # deflate
         if resp.headers.get('Content-encoding', '') == 'deflate':
@@ -601,28 +647,134 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
     https_request = http_request
     https_response = http_response
 
-def unified_strdate(date_str):
+
+class YoutubeDLHTTPSHandler(compat_urllib_request.HTTPSHandler):
+    def __init__(self, params, https_conn_class=None, *args, **kwargs):
+        compat_urllib_request.HTTPSHandler.__init__(self, *args, **kwargs)
+        self._https_conn_class = https_conn_class or compat_http_client.HTTPSConnection
+        self._params = params
+
+    def https_open(self, req):
+        kwargs = {}
+        if hasattr(self, '_context'):  # python > 2.6
+            kwargs['context'] = self._context
+        if hasattr(self, '_check_hostname'):  # python 3.x
+            kwargs['check_hostname'] = self._check_hostname
+        return self.do_open(functools.partial(
+            _create_http_connection, self, self._https_conn_class, True),
+            req, **kwargs)
+
+
+def parse_iso8601(date_str, delimiter='T'):
+    """ Return a UNIX timestamp from the given date """
+
+    if date_str is None:
+        return None
+
+    m = re.search(
+        r'(\.[0-9]+)?(?:Z$| ?(?P<sign>\+|-)(?P<hours>[0-9]{2}):?(?P<minutes>[0-9]{2})$)',
+        date_str)
+    if not m:
+        timezone = datetime.timedelta()
+    else:
+        date_str = date_str[:-len(m.group(0))]
+        if not m.group('sign'):
+            timezone = datetime.timedelta()
+        else:
+            sign = 1 if m.group('sign') == '+' else -1
+            timezone = datetime.timedelta(
+                hours=sign * int(m.group('hours')),
+                minutes=sign * int(m.group('minutes')))
+    date_format = '%Y-%m-%d{0}%H:%M:%S'.format(delimiter)
+    dt = datetime.datetime.strptime(date_str, date_format) - timezone
+    return calendar.timegm(dt.timetuple())
+
+
+def unified_strdate(date_str, day_first=True):
     """Return a string with the date in the format YYYYMMDD"""
+
+    if date_str is None:
+        return None
     upload_date = None
-    #Replace commas
-    date_str = date_str.replace(',',' ')
+    # Replace commas
+    date_str = date_str.replace(',', ' ')
     # %z (UTC offset) is only supported in python>=3.2
-    date_str = re.sub(r' (\+|-)[\d]*$', '', date_str)
-    format_expressions = ['%d %B %Y', '%B %d %Y', '%b %d %Y', '%Y-%m-%d', '%d/%m/%Y', '%Y/%m/%d %H:%M:%S']
+    date_str = re.sub(r' ?(\+|-)[0-9]{2}:?[0-9]{2}$', '', date_str)
+    # Remove AM/PM + timezone
+    date_str = re.sub(r'(?i)\s*(?:AM|PM)(?:\s+[A-Z]+)?', '', date_str)
+
+    format_expressions = [
+        '%d %B %Y',
+        '%d %b %Y',
+        '%B %d %Y',
+        '%b %d %Y',
+        '%b %dst %Y %I:%M%p',
+        '%b %dnd %Y %I:%M%p',
+        '%b %dth %Y %I:%M%p',
+        '%Y %m %d',
+        '%Y-%m-%d',
+        '%Y/%m/%d',
+        '%Y/%m/%d %H:%M:%S',
+        '%Y-%m-%d %H:%M:%S',
+        '%Y-%m-%d %H:%M:%S.%f',
+        '%d.%m.%Y %H:%M',
+        '%d.%m.%Y %H.%M',
+        '%Y-%m-%dT%H:%M:%SZ',
+        '%Y-%m-%dT%H:%M:%S.%fZ',
+        '%Y-%m-%dT%H:%M:%S.%f0Z',
+        '%Y-%m-%dT%H:%M:%S',
+        '%Y-%m-%dT%H:%M:%S.%f',
+        '%Y-%m-%dT%H:%M',
+    ]
+    if day_first:
+        format_expressions.extend([
+            '%d.%m.%Y',
+            '%d/%m/%Y',
+            '%d/%m/%y',
+            '%d/%m/%Y %H:%M:%S',
+        ])
+    else:
+        format_expressions.extend([
+            '%m.%d.%Y',
+            '%m/%d/%Y',
+            '%m/%d/%y',
+            '%m/%d/%Y %H:%M:%S',
+        ])
     for expression in format_expressions:
         try:
             upload_date = datetime.datetime.strptime(date_str, expression).strftime('%Y%m%d')
-        except:
+        except ValueError:
             pass
+    if upload_date is None:
+        timetuple = email.utils.parsedate_tz(date_str)
+        if timetuple:
+            upload_date = datetime.datetime(*timetuple[:6]).strftime('%Y%m%d')
     return upload_date
 
+
+def determine_ext(url, default_ext='unknown_video'):
+    if url is None:
+        return default_ext
+    guess = url.partition('?')[0].rpartition('.')[2]
+    if re.match(r'^[A-Za-z0-9]+$', guess):
+        return guess
+    else:
+        return default_ext
+
+
+def subtitles_filename(filename, sub_lang, sub_format):
+    return filename.rsplit('.', 1)[0] + '.' + sub_lang + '.' + sub_format
+
+
 def date_from_str(date_str):
     """
     Return a datetime object from a string in the format YYYYMMDD or
     (now|today)[+-][0-9](day|week|month|year)(s)?"""
     today = datetime.date.today()
-    if date_str == 'now'or date_str == 'today':
+    if date_str in ('now', 'today'):
         return today
+    if date_str == 'yesterday':
+        return today - datetime.timedelta(days=1)
     match = re.match('(now|today)(?P<sign>[+-])(?P<time>\d+)(?P<unit>day|week|month|year)(s)?', date_str)
     if match is not None:
         sign = match.group('sign')
@@ -630,7 +782,7 @@ def date_from_str(date_str):
         if sign == '-':
             time = -time
         unit = match.group('unit')
-        #A bad aproximation?
+        # A bad aproximation?
         if unit == 'month':
             unit = 'day'
             time *= 30
@@ -641,9 +793,21 @@ def date_from_str(date_str):
         delta = datetime.timedelta(**{unit: time})
         return today + delta
     return datetime.datetime.strptime(date_str, "%Y%m%d").date()
-    
+
+
+def hyphenate_date(date_str):
+    """
+    Convert a date in 'YYYYMMDD' format to 'YYYY-MM-DD' format"""
+    match = re.match(r'^(\d\d\d\d)(\d\d)(\d\d)$', date_str)
+    if match is not None:
+        return '-'.join(match.groups())
+    else:
+        return date_str
+
+
 class DateRange(object):
     """Represents a time interval between two dates"""
+
     def __init__(self, start=None, end=None):
         """start and end must be strings in the format accepted by date"""
         if start is not None:
@@ -656,14 +820,861 @@ class DateRange(object):
             self.end = datetime.datetime.max.date()
         if self.start > self.end:
             raise ValueError('Date range: "%s" , the start date must be before the end date' % self)
+
     @classmethod
     def day(cls, day):
         """Returns a range that only contains the given day"""
-        return cls(day,day)
+        return cls(day, day)
+
     def __contains__(self, date):
         """Check if the date is in the range"""
         if not isinstance(date, datetime.date):
             date = date_from_str(date)
         return self.start <= date <= self.end
+
     def __str__(self):
-        return '%s - %s' % ( self.start.isoformat(), self.end.isoformat())
+        return '%s - %s' % (self.start.isoformat(), self.end.isoformat())
+
+
+def platform_name():
+    """ Returns the platform name as a compat_str """
+    res = platform.platform()
+    if isinstance(res, bytes):
+        res = res.decode(preferredencoding())
+
+    assert isinstance(res, compat_str)
+    return res
+
+
+def _windows_write_string(s, out):
+    """ Returns True if the string was written using special methods,
+    False if it has yet to be written out."""
+    # Adapted from http://stackoverflow.com/a/3259271/35070
+
+    import ctypes
+    import ctypes.wintypes
+
+    WIN_OUTPUT_IDS = {
+        1: -11,
+        2: -12,
+    }
+
+    try:
+        fileno = out.fileno()
+    except AttributeError:
+        # If the output stream doesn't have a fileno, it's virtual
+        return False
+    except io.UnsupportedOperation:
+        # Some strange Windows pseudo files?
+        return False
+    if fileno not in WIN_OUTPUT_IDS:
+        return False
+
+    GetStdHandle = ctypes.WINFUNCTYPE(
+        ctypes.wintypes.HANDLE, ctypes.wintypes.DWORD)(
+        (b"GetStdHandle", ctypes.windll.kernel32))
+    h = GetStdHandle(WIN_OUTPUT_IDS[fileno])
+
+    WriteConsoleW = ctypes.WINFUNCTYPE(
+        ctypes.wintypes.BOOL, ctypes.wintypes.HANDLE, ctypes.wintypes.LPWSTR,
+        ctypes.wintypes.DWORD, ctypes.POINTER(ctypes.wintypes.DWORD),
+        ctypes.wintypes.LPVOID)((b"WriteConsoleW", ctypes.windll.kernel32))
+    written = ctypes.wintypes.DWORD(0)
+
+    GetFileType = ctypes.WINFUNCTYPE(ctypes.wintypes.DWORD, ctypes.wintypes.DWORD)((b"GetFileType", ctypes.windll.kernel32))
+    FILE_TYPE_CHAR = 0x0002
+    FILE_TYPE_REMOTE = 0x8000
+    GetConsoleMode = ctypes.WINFUNCTYPE(
+        ctypes.wintypes.BOOL, ctypes.wintypes.HANDLE,
+        ctypes.POINTER(ctypes.wintypes.DWORD))(
+        (b"GetConsoleMode", ctypes.windll.kernel32))
+    INVALID_HANDLE_VALUE = ctypes.wintypes.DWORD(-1).value
+
+    def not_a_console(handle):
+        if handle == INVALID_HANDLE_VALUE or handle is None:
+            return True
+        return ((GetFileType(handle) & ~FILE_TYPE_REMOTE) != FILE_TYPE_CHAR
+                or GetConsoleMode(handle, ctypes.byref(ctypes.wintypes.DWORD())) == 0)
+
+    if not_a_console(h):
+        return False
+
+    def next_nonbmp_pos(s):
+        try:
+            return next(i for i, c in enumerate(s) if ord(c) > 0xffff)
+        except StopIteration:
+            return len(s)
+
+    while s:
+        count = min(next_nonbmp_pos(s), 1024)
+
+        ret = WriteConsoleW(
+            h, s, count if count else 2, ctypes.byref(written), None)
+        if ret == 0:
+            raise OSError('Failed to write string')
+        if not count:  # We just wrote a non-BMP character
+            assert written.value == 2
+            s = s[1:]
+        else:
+            assert written.value > 0
+            s = s[written.value:]
+    return True
+
+
+def write_string(s, out=None, encoding=None):
+    if out is None:
+        out = sys.stderr
+    assert type(s) == compat_str
+
+    if sys.platform == 'win32' and encoding is None and hasattr(out, 'fileno'):
+        if _windows_write_string(s, out):
+            return
+
+    if ('b' in getattr(out, 'mode', '') or
+            sys.version_info[0] < 3):  # Python 2 lies about mode of sys.stderr
+        byt = s.encode(encoding or preferredencoding(), 'ignore')
+        out.write(byt)
+    elif hasattr(out, 'buffer'):
+        enc = encoding or getattr(out, 'encoding', None) or preferredencoding()
+        byt = s.encode(enc, 'ignore')
+        out.buffer.write(byt)
+    else:
+        out.write(s)
+    out.flush()
+
+
+def bytes_to_intlist(bs):
+    if not bs:
+        return []
+    if isinstance(bs[0], int):  # Python 3
+        return list(bs)
+    else:
+        return [ord(c) for c in bs]
+
+
+def intlist_to_bytes(xs):
+    if not xs:
+        return b''
+    return struct_pack('%dB' % len(xs), *xs)
+
+
+# Cross-platform file locking
+if sys.platform == 'win32':
+    import ctypes.wintypes
+    import msvcrt
+
+    class OVERLAPPED(ctypes.Structure):
+        _fields_ = [
+            ('Internal', ctypes.wintypes.LPVOID),
+            ('InternalHigh', ctypes.wintypes.LPVOID),
+            ('Offset', ctypes.wintypes.DWORD),
+            ('OffsetHigh', ctypes.wintypes.DWORD),
+            ('hEvent', ctypes.wintypes.HANDLE),
+        ]
+
+    kernel32 = ctypes.windll.kernel32
+    LockFileEx = kernel32.LockFileEx
+    LockFileEx.argtypes = [
+        ctypes.wintypes.HANDLE,     # hFile
+        ctypes.wintypes.DWORD,      # dwFlags
+        ctypes.wintypes.DWORD,      # dwReserved
+        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
+        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
+        ctypes.POINTER(OVERLAPPED)  # Overlapped
+    ]
+    LockFileEx.restype = ctypes.wintypes.BOOL
+    UnlockFileEx = kernel32.UnlockFileEx
+    UnlockFileEx.argtypes = [
+        ctypes.wintypes.HANDLE,     # hFile
+        ctypes.wintypes.DWORD,      # dwReserved
+        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
+        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
+        ctypes.POINTER(OVERLAPPED)  # Overlapped
+    ]
+    UnlockFileEx.restype = ctypes.wintypes.BOOL
+    whole_low = 0xffffffff
+    whole_high = 0x7fffffff
+
+    def _lock_file(f, exclusive):
+        overlapped = OVERLAPPED()
+        overlapped.Offset = 0
+        overlapped.OffsetHigh = 0
+        overlapped.hEvent = 0
+        f._lock_file_overlapped_p = ctypes.pointer(overlapped)
+        handle = msvcrt.get_osfhandle(f.fileno())
+        if not LockFileEx(handle, 0x2 if exclusive else 0x0, 0,
+                          whole_low, whole_high, f._lock_file_overlapped_p):
+            raise OSError('Locking file failed: %r' % ctypes.FormatError())
+
+    def _unlock_file(f):
+        assert f._lock_file_overlapped_p
+        handle = msvcrt.get_osfhandle(f.fileno())
+        if not UnlockFileEx(handle, 0,
+                            whole_low, whole_high, f._lock_file_overlapped_p):
+            raise OSError('Unlocking file failed: %r' % ctypes.FormatError())
+
+else:
+    import fcntl
+
+    def _lock_file(f, exclusive):
+        fcntl.flock(f, fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH)
+
+    def _unlock_file(f):
+        fcntl.flock(f, fcntl.LOCK_UN)
+
+
+class locked_file(object):
+    def __init__(self, filename, mode, encoding=None):
+        assert mode in ['r', 'a', 'w']
+        self.f = io.open(filename, mode, encoding=encoding)
+        self.mode = mode
+
+    def __enter__(self):
+        exclusive = self.mode != 'r'
+        try:
+            _lock_file(self.f, exclusive)
+        except IOError:
+            self.f.close()
+            raise
+        return self
+
+    def __exit__(self, etype, value, traceback):
+        try:
+            _unlock_file(self.f)
+        finally:
+            self.f.close()
+
+    def __iter__(self):
+        return iter(self.f)
+
+    def write(self, *args):
+        return self.f.write(*args)
+
+    def read(self, *args):
+        return self.f.read(*args)
+
+
+def get_filesystem_encoding():
+    encoding = sys.getfilesystemencoding()
+    return encoding if encoding is not None else 'utf-8'
+
+
+def shell_quote(args):
+    quoted_args = []
+    encoding = get_filesystem_encoding()
+    for a in args:
+        if isinstance(a, bytes):
+            # We may get a filename encoded with 'encodeFilename'
+            a = a.decode(encoding)
+        quoted_args.append(pipes.quote(a))
+    return ' '.join(quoted_args)
+
+
+def takewhile_inclusive(pred, seq):
+    """ Like itertools.takewhile, but include the latest evaluated element
+        (the first element so that Not pred(e)) """
+    for e in seq:
+        yield e
+        if not pred(e):
+            return
+
+
+def smuggle_url(url, data):
+    """ Pass additional data in a URL for internal use. """
+
+    sdata = compat_urllib_parse.urlencode(
+        {'__youtubedl_smuggle': json.dumps(data)})
+    return url + '#' + sdata
+
+
+def unsmuggle_url(smug_url, default=None):
+    if '#__youtubedl_smuggle' not in smug_url:
+        return smug_url, default
+    url, _, sdata = smug_url.rpartition('#')
+    jsond = compat_parse_qs(sdata)['__youtubedl_smuggle'][0]
+    data = json.loads(jsond)
+    return url, data
+
+
+def format_bytes(bytes):
+    if bytes is None:
+        return 'N/A'
+    if type(bytes) is str:
+        bytes = float(bytes)
+    if bytes == 0.0:
+        exponent = 0
+    else:
+        exponent = int(math.log(bytes, 1024.0))
+    suffix = ['B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB'][exponent]
+    converted = float(bytes) / float(1024 ** exponent)
+    return '%.2f%s' % (converted, suffix)
+
+
+def parse_filesize(s):
+    if s is None:
+        return None
+
+    # The lower-case forms are of course incorrect and inofficial,
+    # but we support those too
+    _UNIT_TABLE = {
+        'B': 1,
+        'b': 1,
+        'KiB': 1024,
+        'KB': 1000,
+        'kB': 1024,
+        'Kb': 1000,
+        'MiB': 1024 ** 2,
+        'MB': 1000 ** 2,
+        'mB': 1024 ** 2,
+        'Mb': 1000 ** 2,
+        'GiB': 1024 ** 3,
+        'GB': 1000 ** 3,
+        'gB': 1024 ** 3,
+        'Gb': 1000 ** 3,
+        'TiB': 1024 ** 4,
+        'TB': 1000 ** 4,
+        'tB': 1024 ** 4,
+        'Tb': 1000 ** 4,
+        'PiB': 1024 ** 5,
+        'PB': 1000 ** 5,
+        'pB': 1024 ** 5,
+        'Pb': 1000 ** 5,
+        'EiB': 1024 ** 6,
+        'EB': 1000 ** 6,
+        'eB': 1024 ** 6,
+        'Eb': 1000 ** 6,
+        'ZiB': 1024 ** 7,
+        'ZB': 1000 ** 7,
+        'zB': 1024 ** 7,
+        'Zb': 1000 ** 7,
+        'YiB': 1024 ** 8,
+        'YB': 1000 ** 8,
+        'yB': 1024 ** 8,
+        'Yb': 1000 ** 8,
+    }
+
+    units_re = '|'.join(re.escape(u) for u in _UNIT_TABLE)
+    m = re.match(
+        r'(?P<num>[0-9]+(?:[,.][0-9]*)?)\s*(?P<unit>%s)' % units_re, s)
+    if not m:
+        return None
+
+    num_str = m.group('num').replace(',', '.')
+    mult = _UNIT_TABLE[m.group('unit')]
+    return int(float(num_str) * mult)
+
+
+def get_term_width():
+    columns = compat_getenv('COLUMNS', None)
+    if columns:
+        return int(columns)
+
+    try:
+        sp = subprocess.Popen(
+            ['stty', 'size'],
+            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        out, err = sp.communicate()
+        return int(out.split()[1])
+    except:
+        pass
+    return None
+
+
+def month_by_name(name):
+    """ Return the number of a month by (locale-independently) English name """
+
+    ENGLISH_NAMES = [
+        'January', 'February', 'March', 'April', 'May', 'June',
+        'July', 'August', 'September', 'October', 'November', 'December']
+    try:
+        return ENGLISH_NAMES.index(name) + 1
+    except ValueError:
+        return None
+
+
+def fix_xml_ampersands(xml_str):
+    """Replace all the '&' by '&amp;' in XML"""
+    return re.sub(
+        r'&(?!amp;|lt;|gt;|apos;|quot;|#x[0-9a-fA-F]{,4};|#[0-9]{,4};)',
+        '&amp;',
+        xml_str)
+
+
+def setproctitle(title):
+    assert isinstance(title, compat_str)
+    try:
+        libc = ctypes.cdll.LoadLibrary("libc.so.6")
+    except OSError:
+        return
+    title_bytes = title.encode('utf-8')
+    buf = ctypes.create_string_buffer(len(title_bytes))
+    buf.value = title_bytes
+    try:
+        libc.prctl(15, buf, 0, 0, 0)
+    except AttributeError:
+        return  # Strange libc, just skip this
+
+
+def remove_start(s, start):
+    if s.startswith(start):
+        return s[len(start):]
+    return s
+
+
+def remove_end(s, end):
+    if s.endswith(end):
+        return s[:-len(end)]
+    return s
+
+
+def url_basename(url):
+    path = compat_urlparse.urlparse(url).path
+    return path.strip('/').split('/')[-1]
+
+
+class HEADRequest(compat_urllib_request.Request):
+    def get_method(self):
+        return "HEAD"
+
+
+def int_or_none(v, scale=1, default=None, get_attr=None, invscale=1):
+    if get_attr:
+        if v is not None:
+            v = getattr(v, get_attr, None)
+    if v == '':
+        v = None
+    return default if v is None else (int(v) * invscale // scale)
+
+
+def str_or_none(v, default=None):
+    return default if v is None else compat_str(v)
+
+
+def str_to_int(int_str):
+    """ A more relaxed version of int_or_none """
+    if int_str is None:
+        return None
+    int_str = re.sub(r'[,\.\+]', '', int_str)
+    return int(int_str)
+
+
+def float_or_none(v, scale=1, invscale=1, default=None):
+    return default if v is None else (float(v) * invscale / scale)
+
+
+def parse_duration(s):
+    if not isinstance(s, compat_basestring):
+        return None
+
+    s = s.strip()
+
+    m = re.match(
+        r'''(?ix)(?:P?T)?
+        (?:
+            (?P<only_mins>[0-9.]+)\s*(?:mins?|minutes?)\s*|
+            (?P<only_hours>[0-9.]+)\s*(?:hours?)|
+
+            (?:
+                (?:
+                    (?:(?P<days>[0-9]+)\s*(?:[:d]|days?)\s*)?
+                    (?P<hours>[0-9]+)\s*(?:[:h]|hours?)\s*
+                )?
+                (?P<mins>[0-9]+)\s*(?:[:m]|mins?|minutes?)\s*
+            )?
+            (?P<secs>[0-9]+)(?P<ms>\.[0-9]+)?\s*(?:s|secs?|seconds?)?
+        )$''', s)
+    if not m:
+        return None
+    res = 0
+    if m.group('only_mins'):
+        return float_or_none(m.group('only_mins'), invscale=60)
+    if m.group('only_hours'):
+        return float_or_none(m.group('only_hours'), invscale=60 * 60)
+    if m.group('secs'):
+        res += int(m.group('secs'))
+    if m.group('mins'):
+        res += int(m.group('mins')) * 60
+    if m.group('hours'):
+        res += int(m.group('hours')) * 60 * 60
+    if m.group('days'):
+        res += int(m.group('days')) * 24 * 60 * 60
+    if m.group('ms'):
+        res += float(m.group('ms'))
+    return res
+
+
+def prepend_extension(filename, ext):
+    name, real_ext = os.path.splitext(filename)
+    return '{0}.{1}{2}'.format(name, ext, real_ext)
+
+
+def check_executable(exe, args=[]):
+    """ Checks if the given binary is installed somewhere in PATH, and returns its name.
+    args can be a list of arguments for a short output (like -version) """
+    try:
+        subprocess.Popen([exe] + args, stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
+    except OSError:
+        return False
+    return exe
+
+
+def get_exe_version(exe, args=['--version'],
+                    version_re=None, unrecognized='present'):
+    """ Returns the version of the specified executable,
+    or False if the executable is not present """
+    try:
+        out, _ = subprocess.Popen(
+            [exe] + args,
+            stdout=subprocess.PIPE, stderr=subprocess.STDOUT).communicate()
+    except OSError:
+        return False
+    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:
+        return unrecognized
+
+
+class PagedList(object):
+    def __len__(self):
+        # This is only useful for tests
+        return len(self.getslice())
+
+
+class OnDemandPagedList(PagedList):
+    def __init__(self, pagefunc, pagesize):
+        self._pagefunc = pagefunc
+        self._pagesize = pagesize
+
+    def getslice(self, start=0, end=None):
+        res = []
+        for pagenum in itertools.count(start // self._pagesize):
+            firstid = pagenum * self._pagesize
+            nextfirstid = pagenum * self._pagesize + self._pagesize
+            if start >= nextfirstid:
+                continue
+
+            page_results = list(self._pagefunc(pagenum))
+
+            startv = (
+                start % self._pagesize
+                if firstid <= start < nextfirstid
+                else 0)
+
+            endv = (
+                ((end - 1) % self._pagesize) + 1
+                if (end is not None and firstid <= end <= nextfirstid)
+                else None)
+
+            if startv != 0 or endv is not None:
+                page_results = page_results[startv:endv]
+            res.extend(page_results)
+
+            # A little optimization - if current page is not "full", ie. does
+            # not contain page_size videos then we can assume that this page
+            # is the last one - there are no more ids on further pages -
+            # i.e. no need to query again.
+            if len(page_results) + startv < self._pagesize:
+                break
+
+            # If we got the whole page, but the next page is not interesting,
+            # break out early as well
+            if end == nextfirstid:
+                break
+        return res
+
+
+class InAdvancePagedList(PagedList):
+    def __init__(self, pagefunc, pagecount, pagesize):
+        self._pagefunc = pagefunc
+        self._pagecount = pagecount
+        self._pagesize = pagesize
+
+    def getslice(self, start=0, end=None):
+        res = []
+        start_page = start // self._pagesize
+        end_page = (
+            self._pagecount if end is None else (end // self._pagesize + 1))
+        skip_elems = start - start_page * self._pagesize
+        only_more = None if end is None else end - start
+        for pagenum in range(start_page, end_page):
+            page = list(self._pagefunc(pagenum))
+            if skip_elems:
+                page = page[skip_elems:]
+                skip_elems = None
+            if only_more is not None:
+                if len(page) < only_more:
+                    only_more -= len(page)
+                else:
+                    page = page[:only_more]
+                    res.extend(page)
+                    break
+            res.extend(page)
+        return res
+
+
+def uppercase_escape(s):
+    unicode_escape = codecs.getdecoder('unicode_escape')
+    return re.sub(
+        r'\\U[0-9a-fA-F]{8}',
+        lambda m: unicode_escape(m.group(0))[0],
+        s)
+
+
+def escape_rfc3986(s):
+    """Escape non-ASCII characters as suggested by RFC 3986"""
+    if sys.version_info < (3, 0) and isinstance(s, compat_str):
+        s = s.encode('utf-8')
+    return compat_urllib_parse.quote(s, b"%/;:@&=+$,!~*'()?#[]")
+
+
+def escape_url(url):
+    """Escape URL as suggested by RFC 3986"""
+    url_parsed = compat_urllib_parse_urlparse(url)
+    return url_parsed._replace(
+        path=escape_rfc3986(url_parsed.path),
+        params=escape_rfc3986(url_parsed.params),
+        query=escape_rfc3986(url_parsed.query),
+        fragment=escape_rfc3986(url_parsed.fragment)
+    ).geturl()
+
+try:
+    struct.pack('!I', 0)
+except TypeError:
+    # In Python 2.6 (and some 2.7 versions), struct requires a bytes argument
+    def struct_pack(spec, *args):
+        if isinstance(spec, compat_str):
+            spec = spec.encode('ascii')
+        return struct.pack(spec, *args)
+
+    def struct_unpack(spec, *args):
+        if isinstance(spec, compat_str):
+            spec = spec.encode('ascii')
+        return struct.unpack(spec, *args)
+else:
+    struct_pack = struct.pack
+    struct_unpack = struct.unpack
+
+
+def read_batch_urls(batch_fd):
+    def fixup(url):
+        if not isinstance(url, compat_str):
+            url = url.decode('utf-8', 'replace')
+        BOM_UTF8 = '\xef\xbb\xbf'
+        if url.startswith(BOM_UTF8):
+            url = url[len(BOM_UTF8):]
+        url = url.strip()
+        if url.startswith(('#', ';', ']')):
+            return False
+        return url
+
+    with contextlib.closing(batch_fd) as fd:
+        return [url for url in map(fixup, fd) if url]
+
+
+def urlencode_postdata(*args, **kargs):
+    return compat_urllib_parse.urlencode(*args, **kargs).encode('ascii')
+
+
+try:
+    etree_iter = xml.etree.ElementTree.Element.iter
+except AttributeError:  # Python <=2.6
+    etree_iter = lambda n: n.findall('.//*')
+
+
+def parse_xml(s):
+    class TreeBuilder(xml.etree.ElementTree.TreeBuilder):
+        def doctype(self, name, pubid, system):
+            pass  # Ignore doctypes
+
+    parser = xml.etree.ElementTree.XMLParser(target=TreeBuilder())
+    kwargs = {'parser': parser} if sys.version_info >= (2, 7) else {}
+    tree = xml.etree.ElementTree.XML(s.encode('utf-8'), **kwargs)
+    # Fix up XML parser in Python 2.x
+    if sys.version_info < (3, 0):
+        for n in etree_iter(tree):
+            if n.text is not None:
+                if not isinstance(n.text, compat_str):
+                    n.text = n.text.decode('utf-8')
+    return tree
+
+
+US_RATINGS = {
+    'G': 0,
+    'PG': 10,
+    'PG-13': 13,
+    'R': 16,
+    'NC': 18,
+}
+
+
+def parse_age_limit(s):
+    if s is None:
+        return None
+    m = re.match(r'^(?P<age>\d{1,2})\+?$', s)
+    return int(m.group('age')) if m else US_RATINGS.get(s, None)
+
+
+def strip_jsonp(code):
+    return re.sub(
+        r'(?s)^[a-zA-Z0-9_]+\s*\(\s*(.*)\);?\s*?(?://[^\n]*)*$', r'\1', code)
+
+
+def js_to_json(code):
+    def fix_kv(m):
+        v = m.group(0)
+        if v in ('true', 'false', 'null'):
+            return v
+        if v.startswith('"'):
+            return v
+        if v.startswith("'"):
+            v = v[1:-1]
+            v = re.sub(r"\\\\|\\'|\"", lambda m: {
+                '\\\\': '\\\\',
+                "\\'": "'",
+                '"': '\\"',
+            }[m.group(0)], v)
+        return '"%s"' % v
+
+    res = re.sub(r'''(?x)
+        "(?:[^"\\]*(?:\\\\|\\")?)*"|
+        '(?:[^'\\]*(?:\\\\|\\')?)*'|
+        [a-zA-Z_][.a-zA-Z_0-9]*
+        ''', fix_kv, code)
+    res = re.sub(r',(\s*\])', lambda m: m.group(1), res)
+    return res
+
+
+def qualities(quality_ids):
+    """ Get a numeric quality value out of a list of possible values """
+    def q(qid):
+        try:
+            return quality_ids.index(qid)
+        except ValueError:
+            return -1
+    return q
+
+
+DEFAULT_OUTTMPL = '%(title)s-%(id)s.%(ext)s'
+
+
+def limit_length(s, length):
+    """ Add ellipses to overly long strings """
+    if s is None:
+        return None
+    ELLIPSES = '...'
+    if len(s) > length:
+        return s[:length - len(ELLIPSES)] + ELLIPSES
+    return s
+
+
+def version_tuple(v):
+    return tuple(int(e) for e in re.split(r'[-.]', v))
+
+
+def is_outdated_version(version, limit, assume_new=True):
+    if not version:
+        return not assume_new
+    try:
+        return version_tuple(version) < version_tuple(limit)
+    except ValueError:
+        return not assume_new
+
+
+def ytdl_is_updateable():
+    """ Returns if youtube-dl can be updated with -U """
+    from zipimport import zipimporter
+
+    return isinstance(globals().get('__loader__'), zipimporter) or hasattr(sys, 'frozen')
+
+
+def args_to_str(args):
+    # Get a short string representation for a subprocess command
+    return ' '.join(shlex_quote(a) for a in args)
+
+
+def urlhandle_detect_ext(url_handle):
+    try:
+        url_handle.headers
+        getheader = lambda h: url_handle.headers[h]
+    except AttributeError:  # Python < 3
+        getheader = url_handle.info().getheader
+
+    cd = getheader('Content-Disposition')
+    if cd:
+        m = re.match(r'attachment;\s*filename="(?P<filename>[^"]+)"', cd)
+        if m:
+            e = determine_ext(m.group('filename'), default_ext=None)
+            if e:
+                return e
+
+    return getheader('Content-Type').split("/")[1]
+
+
+def age_restricted(content_limit, age_limit):
+    """ Returns True iff the content should be blocked """
+
+    if age_limit is None:  # No limit set
+        return False
+    if content_limit is None:
+        return False  # Content available for everyone
+    return age_limit < content_limit
+
+
+def is_html(first_bytes):
+    """ Detect whether a file contains HTML by examining its first bytes. """
+
+    BOMS = [
+        (b'\xef\xbb\xbf', 'utf-8'),
+        (b'\x00\x00\xfe\xff', 'utf-32-be'),
+        (b'\xff\xfe\x00\x00', 'utf-32-le'),
+        (b'\xff\xfe', 'utf-16-le'),
+        (b'\xfe\xff', 'utf-16-be'),
+    ]
+    for bom, enc in BOMS:
+        if first_bytes.startswith(bom):
+            s = first_bytes[len(bom):].decode(enc, 'replace')
+            break
+    else:
+        s = first_bytes.decode('utf-8', 'replace')
+
+    return re.match(r'^\s*<', s)
+
+
+def determine_protocol(info_dict):
+    protocol = info_dict.get('protocol')
+    if protocol is not None:
+        return protocol
+
+    url = info_dict['url']
+    if url.startswith('rtmp'):
+        return 'rtmp'
+    elif url.startswith('mms'):
+        return 'mms'
+    elif url.startswith('rtsp'):
+        return 'rtsp'
+
+    ext = determine_ext(url)
+    if ext == 'm3u8':
+        return 'm3u8'
+    elif ext == 'f4m':
+        return 'f4m'
+
+    return compat_urllib_parse_urlparse(url).scheme
+
+
+def render_table(header_row, data):
+    """ Render a list of rows, each as a list of values """
+    table = [header_row] + data
+    max_lens = [max(len(compat_str(v)) for v in col) for col in zip(*table)]
+    format_str = ' '.join('%-' + compat_str(ml + 1) + 's' for ml in max_lens[:-1]) + '%s'
+    return '\n'.join(format_str % tuple(row) for row in table)