FM / python3.8

/snap/core20/2866/usr/lib/python3.8

Name	Size	Mode	Actions
asyncio/	-	0755	rm
collections/	-	0755	rm
concurrent/	-	0755	rm
ctypes/	-	0755	rm
curses/	-	0755	rm
dbm/	-	0755	rm
distutils/	-	0755	rm
email/	-	0755	rm
encodings/	-	0755	rm
html/	-	0755	rm
http/	-	0755	rm
importlib/	-	0755	rm
json/	-	0755	rm
lib-dynload/	-	0755	rm
lib2to3/	-	0755	rm
logging/	-	0755	rm
multiprocessing/	-	0755	rm
pydoc_data/	-	0755	rm
sqlite3/	-	0755	rm
test/	-	0755	rm
unittest/	-	0755	rm
urllib/	-	0755	rm
venv/	-	0755	rm
wsgiref/	-	0755	rm
xml/	-	0755	rm
xmlrpc/	-	0755	rm
__pycache__/	-	0755	rm
abc.py	4489	0644	edit dl rm
aifc.py	32814	0644	edit dl rm
antigravity.py	477	0644	edit dl rm
argparse.py	96311	0644	edit dl rm
ast.py	19234	0644	edit dl rm
asynchat.py	11328	0644	edit dl rm
asyncore.py	20094	0644	edit dl rm
base64.py	20382	0755	edit dl rm
bdb.py	32056	0644	edit dl rm
binhex.py	13954	0644	edit dl rm
bisect.py	2214	0644	edit dl rm
bz2.py	12558	0644	edit dl rm
calendar.py	24832	0644	edit dl rm
cgi.py	33932	0755	edit dl rm
cgitb.py	12096	0644	edit dl rm
chunk.py	5435	0644	edit dl rm
cmd.py	14860	0644	edit dl rm
code.py	10622	0644	edit dl rm
codecs.py	36667	0644	edit dl rm
codeop.py	6330	0644	edit dl rm
colorsys.py	4064	0644	edit dl rm
compileall.py	13678	0644	edit dl rm
configparser.py	54374	0644	edit dl rm
contextlib.py	24995	0644	edit dl rm
contextvars.py	129	0644	edit dl rm
copy.py	8661	0644	edit dl rm
copyreg.py	7135	0644	edit dl rm
cProfile.py	6998	0755	edit dl rm
crypt.py	3610	0644	edit dl rm
csv.py	16144	0644	edit dl rm
dataclasses.py	49973	0644	edit dl rm
datetime.py	88287	0644	edit dl rm
decimal.py	320	0644	edit dl rm
difflib.py	84058	0644	edit dl rm
dis.py	20570	0644	edit dl rm
doctest.py	104543	0644	edit dl rm
dummy_threading.py	2815	0644	edit dl rm
enum.py	38136	0644	edit dl rm
filecmp.py	9830	0644	edit dl rm
fileinput.py	14709	0644	edit dl rm
fnmatch.py	4079	0644	edit dl rm
formatter.py	15143	0644	edit dl rm
fractions.py	24329	0644	edit dl rm
ftplib.py	35129	0644	edit dl rm
functools.py	37406	0644	edit dl rm
genericpath.py	4975	0644	edit dl rm
getopt.py	7489	0644	edit dl rm
getpass.py	5994	0644	edit dl rm
gettext.py	27565	0644	edit dl rm
glob.py	5697	0644	edit dl rm
gzip.py	21413	0644	edit dl rm
hashlib.py	9730	0644	edit dl rm
heapq.py	22877	0644	edit dl rm
hmac.py	6629	0644	edit dl rm
imaplib.py	53606	0644	edit dl rm
imghdr.py	3808	0644	edit dl rm
imp.py	10536	0644	edit dl rm
inspect.py	118550	0644	edit dl rm
io.py	3541	0644	edit dl rm
ipaddress.py	76336	0644	edit dl rm
keyword.py	945	0644	edit dl rm
LICENSE.txt	13925	0644	edit dl rm
linecache.py	5330	0644	edit dl rm
locale.py	78195	0644	edit dl rm
lzma.py	12983	0644	edit dl rm
mailbox.py	78661	0644	edit dl rm
mailcap.py	9067	0644	edit dl rm
mimetypes.py	21664	0644	edit dl rm
modulefinder.py	24430	0644	edit dl rm
netrc.py	5566	0644	edit dl rm
nntplib.py	43261	0644	edit dl rm
ntpath.py	25814	0644	edit dl rm
nturl2path.py	2887	0644	edit dl rm
numbers.py	10244	0644	edit dl rm
opcode.py	5808	0644	edit dl rm
operator.py	10711	0644	edit dl rm
optparse.py	60369	0644	edit dl rm
os.py	38995	0644	edit dl rm
pathlib.py	52610	0644	edit dl rm
pdb.py	62738	0755	edit dl rm
pickle.py	64467	0644	edit dl rm
pickletools.py	93486	0644	edit dl rm
pipes.py	8916	0644	edit dl rm
pkgutil.py	21461	0644	edit dl rm
platform.py	40425	0755	edit dl rm
plistlib.py	32460	0644	edit dl rm
poplib.py	15077	0644	edit dl rm
posixpath.py	15500	0644	edit dl rm
pprint.py	21484	0644	edit dl rm
profile.py	23534	0755	edit dl rm
pstats.py	27345	0644	edit dl rm
pty.py	4807	0644	edit dl rm
pyclbr.py	15255	0644	edit dl rm
pydoc.py	106863	0755	edit dl rm
py_compile.py	8148	0644	edit dl rm
queue.py	11356	0644	edit dl rm
quopri.py	7252	0755	edit dl rm
random.py	28802	0644	edit dl rm
re.py	15861	0644	edit dl rm
reprlib.py	5267	0644	edit dl rm
rlcompleter.py	7097	0644	edit dl rm
runpy.py	12052	0644	edit dl rm
sched.py	6442	0644	edit dl rm
secrets.py	2038	0644	edit dl rm
selectors.py	18561	0644	edit dl rm
shelve.py	8527	0644	edit dl rm
shlex.py	13325	0644	edit dl rm
shutil.py	51474	0644	edit dl rm
signal.py	2273	0644	edit dl rm
site.py	22336	0644	edit dl rm
sitecustomize.py	-	0	edit dl rm
smtpd.py	34709	0755	edit dl rm
smtplib.py	44804	0755	edit dl rm
sndhdr.py	7099	0644	edit dl rm
socket.py	35243	0644	edit dl rm
socketserver.py	27296	0644	edit dl rm
sre_compile.py	26695	0644	edit dl rm
sre_constants.py	7154	0644	edit dl rm
sre_parse.py	40230	0644	edit dl rm
ssl.py	52363	0644	edit dl rm
stat.py	5485	0644	edit dl rm
statistics.py	39690	0644	edit dl rm
string.py	10535	0644	edit dl rm
stringprep.py	12917	0644	edit dl rm
struct.py	257	0644	edit dl rm
subprocess.py	77330	0644	edit dl rm
sunau.py	18375	0644	edit dl rm
symbol.py	2109	0644	edit dl rm
symtable.py	8021	0644	edit dl rm
sysconfig.py	25035	0644	edit dl rm
tabnanny.py	11406	0755	edit dl rm
tarfile.py	95580	0755	edit dl rm
telnetlib.py	23254	0644	edit dl rm
tempfile.py	32920	0644	edit dl rm
textwrap.py	19407	0644	edit dl rm
this.py	1003	0644	edit dl rm
threading.py	50820	0644	edit dl rm
timeit.py	13480	0755	edit dl rm
token.py	2368	0644	edit dl rm
tokenize.py	25841	0644	edit dl rm
trace.py	29858	0755	edit dl rm
traceback.py	23611	0644	edit dl rm
tracemalloc.py	17076	0644	edit dl rm
tty.py	879	0644	edit dl rm
turtle.py	143716	0644	edit dl rm
types.py	9713	0644	edit dl rm
typing.py	68962	0644	edit dl rm
uu.py	6957	0755	edit dl rm
uuid.py	30466	0644	edit dl rm
warnings.py	19688	0644	edit dl rm
wave.py	18230	0644	edit dl rm
weakref.py	21387	0644	edit dl rm
webbrowser.py	24083	0755	edit dl rm
xdrlib.py	5913	0644	edit dl rm
zipapp.py	7535	0644	edit dl rm
zipfile.py	89135	0644	edit dl rm
zipimport.py	30765	0644	edit dl rm
_bootlocale.py	1801	0644	edit dl rm
_collections_abc.py	26100	0644	edit dl rm
_compat_pickle.py	8749	0644	edit dl rm
_compression.py	5340	0644	edit dl rm
_dummy_thread.py	6027	0644	edit dl rm
_markupbase.py	14598	0644	edit dl rm
_osx_support.py	21774	0644	edit dl rm
_pydecimal.py	228666	0644	edit dl rm
_pyio.py	93177	0644	edit dl rm
_py_abc.py	6189	0644	edit dl rm
_sitebuiltins.py	3115	0644	edit dl rm
_strptime.py	25268	0644	edit dl rm
_sysconfigdata__linux_x86_64-linux-gnu.py	25834	0644	edit dl rm
_sysconfigdata__x86_64-linux-gnu.py	25834	0644	edit dl rm
_threading_local.py	7220	0644	edit dl rm
_weakrefset.py	5735	0644	edit dl rm
__future__.py	5147	0644	edit dl rm
__phello__.foo.py	64	0644	edit dl rm

Edit: /snap/core20/2866/usr/lib/python3.8/webbrowser.py (24083B)

#! /usr/bin/python3.8
"""Interfaces for launching and remotely controlling Web browsers."""
# Maintained by Georg Brandl.

import os
import shlex
import shutil
import sys
import subprocess
import threading

__all__ = ["Error", "open", "open_new", "open_new_tab", "get", "register"]

class Error(Exception):
    pass

_lock = threading.RLock()
_browsers = {}                  # Dictionary of available browser controllers
_tryorder = None                # Preference order of available browsers
_os_preferred_browser = None    # The preferred browser

def register(name, klass, instance=None, *, preferred=False):
    """Register a browser connector."""
    with _lock:
        if _tryorder is None:
            register_standard_browsers()
        _browsers[name.lower()] = [klass, instance]

# Preferred browsers go to the front of the list.
        # Need to match to the default browser returned by xdg-settings, which
        # may be of the form e.g. "firefox.desktop".
        if preferred or (_os_preferred_browser and name in _os_preferred_browser):
            _tryorder.insert(0, name)
        else:
            _tryorder.append(name)

def get(using=None):
    """Return a browser launcher instance appropriate for the environment."""
    if _tryorder is None:
        with _lock:
            if _tryorder is None:
                register_standard_browsers()
    if using is not None:
        alternatives = [using]
    else:
        alternatives = _tryorder
    for browser in alternatives:
        if '%s' in browser:
            # User gave us a command line, split it into name and args
            browser = shlex.split(browser)
            if browser[-1] == '&':
                return BackgroundBrowser(browser[:-1])
            else:
                return GenericBrowser(browser)
        else:
            # User gave us a browser name or path.
            try:
                command = _browsers[browser.lower()]
            except KeyError:
                command = _synthesize(browser)
            if command[1] is not None:
                return command[1]
            elif command[0] is not None:
                return command[0]()
    raise Error("could not locate runnable browser")

# Please note: the following definition hides a builtin function.
# It is recommended one does "import webbrowser" and uses webbrowser.open(url)
# instead of "from webbrowser import *".

def open(url, new=0, autoraise=True):
    """Display url using the default browser.

If possible, open url in a location determined by new.
    - 0: the same browser window (the default).
    - 1: a new browser window.
    - 2: a new browser page ("tab").
    If possible, autoraise raises the window (the default) or not.
    """
    if _tryorder is None:
        with _lock:
            if _tryorder is None:
                register_standard_browsers()
    for name in _tryorder:
        browser = get(name)
        if browser.open(url, new, autoraise):
            return True
    return False

def open_new(url):
    """Open url in a new window of the default browser.

If not possible, then open url in the only browser window.
    """
    return open(url, 1)

def open_new_tab(url):
    """Open url in a new page ("tab") of the default browser.

If not possible, then the behavior becomes equivalent to open_new().
    """
    return open(url, 2)

def _synthesize(browser, *, preferred=False):
    """Attempt to synthesize a controller based on existing controllers.

This is useful to create a controller when a user specifies a path to
    an entry in the BROWSER environment variable -- we can copy a general
    controller to operate using a specific installation of the desired
    browser in this way.

If we can't create a controller in this way, or if there is no
    executable for the requested browser, return [None, None].

"""
    cmd = browser.split()[0]
    if not shutil.which(cmd):
        return [None, None]
    name = os.path.basename(cmd)
    try:
        command = _browsers[name.lower()]
    except KeyError:
        return [None, None]
    # now attempt to clone to fit the new name:
    controller = command[1]
    if controller and name.lower() == controller.basename:
        import copy
        controller = copy.copy(controller)
        controller.name = browser
        controller.basename = os.path.basename(browser)
        register(browser, None, instance=controller, preferred=preferred)
        return [None, controller]
    return [None, None]

# General parent classes

class BaseBrowser(object):
    """Parent class for all browsers. Do not use directly."""

args = ['%s']

def __init__(self, name=""):
        self.name = name
        self.basename = name

def open(self, url, new=0, autoraise=True):
        raise NotImplementedError

def open_new(self, url):
        return self.open(url, 1)

def open_new_tab(self, url):
        return self.open(url, 2)

class GenericBrowser(BaseBrowser):
    """Class for all browsers started with a command
       and without remote functionality."""

def __init__(self, name):
        if isinstance(name, str):
            self.name = name
            self.args = ["%s"]
        else:
            # name should be a list with arguments
            self.name = name[0]
            self.args = name[1:]
        self.basename = os.path.basename(self.name)

def open(self, url, new=0, autoraise=True):
        sys.audit("webbrowser.open", url)
        cmdline = [self.name] + [arg.replace("%s", url)
                                 for arg in self.args]
        try:
            if sys.platform[:3] == 'win':
                p = subprocess.Popen(cmdline)
            else:
                p = subprocess.Popen(cmdline, close_fds=True)
            return not p.wait()
        except OSError:
            return False

class BackgroundBrowser(GenericBrowser):
    """Class for all browsers which are to be started in the
       background."""

def open(self, url, new=0, autoraise=True):
        cmdline = [self.name] + [arg.replace("%s", url)
                                 for arg in self.args]
        sys.audit("webbrowser.open", url)
        try:
            if sys.platform[:3] == 'win':
                p = subprocess.Popen(cmdline)
            else:
                p = subprocess.Popen(cmdline, close_fds=True,
                                     start_new_session=True)
            return (p.poll() is None)
        except OSError:
            return False

class UnixBrowser(BaseBrowser):
    """Parent class for all Unix browsers with remote functionality."""

raise_opts = None
    background = False
    redirect_stdout = True
    # In remote_args, %s will be replaced with the requested URL.  %action will
    # be replaced depending on the value of 'new' passed to open.
    # remote_action is used for new=0 (open).  If newwin is not None, it is
    # used for new=1 (open_new).  If newtab is not None, it is used for
    # new=3 (open_new_tab).  After both substitutions are made, any empty
    # strings in the transformed remote_args list will be removed.
    remote_args = ['%action', '%s']
    remote_action = None
    remote_action_newwin = None
    remote_action_newtab = None

def _invoke(self, args, remote, autoraise, url=None):
        raise_opt = []
        if remote and self.raise_opts:
            # use autoraise argument only for remote invocation
            autoraise = int(autoraise)
            opt = self.raise_opts[autoraise]
            if opt: raise_opt = [opt]

cmdline = [self.name] + raise_opt + args

if remote or self.background:
            inout = subprocess.DEVNULL
        else:
            # for TTY browsers, we need stdin/out
            inout = None
        p = subprocess.Popen(cmdline, close_fds=True, stdin=inout,
                             stdout=(self.redirect_stdout and inout or None),
                             stderr=inout, start_new_session=True)
        if remote:
            # wait at most five seconds. If the subprocess is not finished, the
            # remote invocation has (hopefully) started a new instance.
            try:
                rc = p.wait(5)
                # if remote call failed, open() will try direct invocation
                return not rc
            except subprocess.TimeoutExpired:
                return True
        elif self.background:
            if p.poll() is None:
                return True
            else:
                return False
        else:
            return not p.wait()

def open(self, url, new=0, autoraise=True):
        sys.audit("webbrowser.open", url)
        if new == 0:
            action = self.remote_action
        elif new == 1:
            action = self.remote_action_newwin
        elif new == 2:
            if self.remote_action_newtab is None:
                action = self.remote_action_newwin
            else:
                action = self.remote_action_newtab
        else:
            raise Error("Bad 'new' parameter to open(); " +
                        "expected 0, 1, or 2, got %s" % new)

args = [arg.replace("%s", url).replace("%action", action)
                for arg in self.remote_args]
        args = [arg for arg in args if arg]
        success = self._invoke(args, True, autoraise, url)
        if not success:
            # remote invocation failed, try straight way
            args = [arg.replace("%s", url) for arg in self.args]
            return self._invoke(args, False, False)
        else:
            return True

class Mozilla(UnixBrowser):
    """Launcher class for Mozilla browsers."""

remote_args = ['%action', '%s']
    remote_action = ""
    remote_action_newwin = "-new-window"
    remote_action_newtab = "-new-tab"
    background = True

class Netscape(UnixBrowser):
    """Launcher class for Netscape browser."""

raise_opts = ["-noraise", "-raise"]
    remote_args = ['-remote', 'openURL(%s%action)']
    remote_action = ""
    remote_action_newwin = ",new-window"
    remote_action_newtab = ",new-tab"
    background = True

class Galeon(UnixBrowser):
    """Launcher class for Galeon/Epiphany browsers."""

raise_opts = ["-noraise", ""]
    remote_args = ['%action', '%s']
    remote_action = "-n"
    remote_action_newwin = "-w"
    background = True

class Chrome(UnixBrowser):
    "Launcher class for Google Chrome browser."

remote_args = ['%action', '%s']
    remote_action = ""
    remote_action_newwin = "--new-window"
    remote_action_newtab = ""
    background = True

Chromium = Chrome

class Opera(UnixBrowser):
    "Launcher class for Opera browser."

remote_args = ['%action', '%s']
    remote_action = ""
    remote_action_newwin = "--new-window"
    remote_action_newtab = ""
    background = True

class Elinks(UnixBrowser):
    "Launcher class for Elinks browsers."

remote_args = ['-remote', 'openURL(%s%action)']
    remote_action = ""
    remote_action_newwin = ",new-window"
    remote_action_newtab = ",new-tab"
    background = False

# elinks doesn't like its stdout to be redirected -
    # it uses redirected stdout as a signal to do -dump
    redirect_stdout = False

class Konqueror(BaseBrowser):
    """Controller for the KDE File Manager (kfm, or Konqueror).

See the output of ``kfmclient --commands``
    for more information on the Konqueror remote-control interface.
    """

def open(self, url, new=0, autoraise=True):
        sys.audit("webbrowser.open", url)
        # XXX Currently I know no way to prevent KFM from opening a new win.
        if new == 2:
            action = "newTab"
        else:
            action = "openURL"

devnull = subprocess.DEVNULL

try:
            p = subprocess.Popen(["kfmclient", action, url],
                                 close_fds=True, stdin=devnull,
                                 stdout=devnull, stderr=devnull)
        except OSError:
            # fall through to next variant
            pass
        else:
            p.wait()
            # kfmclient's return code unfortunately has no meaning as it seems
            return True

try:
            p = subprocess.Popen(["konqueror", "--silent", url],
                                 close_fds=True, stdin=devnull,
                                 stdout=devnull, stderr=devnull,
                                 start_new_session=True)
        except OSError:
            # fall through to next variant
            pass
        else:
            if p.poll() is None:
                # Should be running now.
                return True

try:
            p = subprocess.Popen(["kfm", "-d", url],
                                 close_fds=True, stdin=devnull,
                                 stdout=devnull, stderr=devnull,
                                 start_new_session=True)
        except OSError:
            return False
        else:
            return (p.poll() is None)

class Grail(BaseBrowser):
    # There should be a way to maintain a connection to Grail, but the
    # Grail remote control protocol doesn't really allow that at this
    # point.  It probably never will!
    def _find_grail_rc(self):
        import glob
        import pwd
        import socket
        import tempfile
        tempdir = os.path.join(tempfile.gettempdir(),
                               ".grail-unix")
        user = pwd.getpwuid(os.getuid())[0]
        filename = os.path.join(glob.escape(tempdir), glob.escape(user) + "-*")
        maybes = glob.glob(filename)
        if not maybes:
            return None
        s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
        for fn in maybes:
            # need to PING each one until we find one that's live
            try:
                s.connect(fn)
            except OSError:
                # no good; attempt to clean it out, but don't fail:
                try:
                    os.unlink(fn)
                except OSError:
                    pass
            else:
                return s

def _remote(self, action):
        s = self._find_grail_rc()
        if not s:
            return 0
        s.send(action)
        s.close()
        return 1

def open(self, url, new=0, autoraise=True):
        sys.audit("webbrowser.open", url)
        if new:
            ok = self._remote("LOADNEW " + url)
        else:
            ok = self._remote("LOAD " + url)
        return ok

#
# Platform support for Unix
#

# These are the right tests because all these Unix browsers require either
# a console terminal or an X display to run.

def register_X_browsers():

# use xdg-open if around
    if shutil.which("xdg-open"):
        register("xdg-open", None, BackgroundBrowser("xdg-open"))

# The default GNOME3 browser
    if "GNOME_DESKTOP_SESSION_ID" in os.environ and shutil.which("gvfs-open"):
        register("gvfs-open", None, BackgroundBrowser("gvfs-open"))

# The default GNOME browser
    if "GNOME_DESKTOP_SESSION_ID" in os.environ and shutil.which("gnome-open"):
        register("gnome-open", None, BackgroundBrowser("gnome-open"))

# The default KDE browser
    if "KDE_FULL_SESSION" in os.environ and shutil.which("kfmclient"):
        register("kfmclient", Konqueror, Konqueror("kfmclient"))

if shutil.which("x-www-browser"):
        register("x-www-browser", None, BackgroundBrowser("x-www-browser"))

# The Mozilla browsers
    for browser in ("firefox", "iceweasel", "iceape", "seamonkey"):
        if shutil.which(browser):
            register(browser, None, Mozilla(browser))

# The Netscape and old Mozilla browsers
    for browser in ("mozilla-firefox",
                    "mozilla-firebird", "firebird",
                    "mozilla", "netscape"):
        if shutil.which(browser):
            register(browser, None, Netscape(browser))

# Konqueror/kfm, the KDE browser.
    if shutil.which("kfm"):
        register("kfm", Konqueror, Konqueror("kfm"))
    elif shutil.which("konqueror"):
        register("konqueror", Konqueror, Konqueror("konqueror"))

# Gnome's Galeon and Epiphany
    for browser in ("galeon", "epiphany"):
        if shutil.which(browser):
            register(browser, None, Galeon(browser))

# Skipstone, another Gtk/Mozilla based browser
    if shutil.which("skipstone"):
        register("skipstone", None, BackgroundBrowser("skipstone"))

# Google Chrome/Chromium browsers
    for browser in ("google-chrome", "chrome", "chromium", "chromium-browser"):
        if shutil.which(browser):
            register(browser, None, Chrome(browser))

# Opera, quite popular
    if shutil.which("opera"):
        register("opera", None, Opera("opera"))

# Next, Mosaic -- old but still in use.
    if shutil.which("mosaic"):
        register("mosaic", None, BackgroundBrowser("mosaic"))

# Grail, the Python browser. Does anybody still use it?
    if shutil.which("grail"):
        register("grail", Grail, None)

def register_standard_browsers():
    global _tryorder
    _tryorder = []

if sys.platform == 'darwin':
        register("MacOSX", None, MacOSXOSAScript('default'))
        register("chrome", None, MacOSXOSAScript('chrome'))
        register("firefox", None, MacOSXOSAScript('firefox'))
        register("safari", None, MacOSXOSAScript('safari'))
        # OS X can use below Unix support (but we prefer using the OS X
        # specific stuff)

if sys.platform[:3] == "win":
        # First try to use the default Windows browser
        register("windows-default", WindowsDefault)

# Detect some common Windows browsers, fallback to IE
        iexplore = os.path.join(os.environ.get("PROGRAMFILES", "C:\\Program Files"),
                                "Internet Explorer\\IEXPLORE.EXE")
        for browser in ("firefox", "firebird", "seamonkey", "mozilla",
                        "netscape", "opera", iexplore):
            if shutil.which(browser):
                register(browser, None, BackgroundBrowser(browser))
    else:
        # Prefer X browsers if present
        if os.environ.get("DISPLAY") or os.environ.get("WAYLAND_DISPLAY"):
            try:
                cmd = "xdg-settings get default-web-browser".split()
                raw_result = subprocess.check_output(cmd, stderr=subprocess.DEVNULL)
                result = raw_result.decode().strip()
            except (FileNotFoundError, subprocess.CalledProcessError, PermissionError, NotADirectoryError) :
                pass
            else:
                global _os_preferred_browser
                _os_preferred_browser = result

register_X_browsers()

# Also try console browsers
        if os.environ.get("TERM"):
            if shutil.which("www-browser"):
                register("www-browser", None, GenericBrowser("www-browser"))
            # The Links/elinks browsers <http://artax.karlin.mff.cuni.cz/~mikulas/links/>
            if shutil.which("links"):
                register("links", None, GenericBrowser("links"))
            if shutil.which("elinks"):
                register("elinks", None, Elinks("elinks"))
            # The Lynx browser <http://lynx.isc.org/>, <http://lynx.browser.org/>
            if shutil.which("lynx"):
                register("lynx", None, GenericBrowser("lynx"))
            # The w3m browser <http://w3m.sourceforge.net/>
            if shutil.which("w3m"):
                register("w3m", None, GenericBrowser("w3m"))

# OK, now that we know what the default preference orders for each
    # platform are, allow user to override them with the BROWSER variable.
    if "BROWSER" in os.environ:
        userchoices = os.environ["BROWSER"].split(os.pathsep)
        userchoices.reverse()

# Treat choices in same way as if passed into get() but do register
        # and prepend to _tryorder
        for cmdline in userchoices:
            if cmdline != '':
                cmd = _synthesize(cmdline, preferred=True)
                if cmd[1] is None:
                    register(cmdline, None, GenericBrowser(cmdline), preferred=True)

# what to do if _tryorder is now empty?

#
# Platform support for Windows
#

if sys.platform[:3] == "win":
    class WindowsDefault(BaseBrowser):
        def open(self, url, new=0, autoraise=True):
            sys.audit("webbrowser.open", url)
            try:
                os.startfile(url)
            except OSError:
                # [Error 22] No application is associated with the specified
                # file for this operation: '<URL>'
                return False
            else:
                return True

#
# Platform support for MacOS
#

if sys.platform == 'darwin':
    # Adapted from patch submitted to SourceForge by Steven J. Burr
    class MacOSX(BaseBrowser):
        """Launcher class for Aqua browsers on Mac OS X

Optionally specify a browser name on instantiation.  Note that this
        will not work for Aqua browsers if the user has moved the application
        package after installation.

If no browser is specified, the default browser, as specified in the
        Internet System Preferences panel, will be used.
        """
        def __init__(self, name):
            self.name = name

def open(self, url, new=0, autoraise=True):
            sys.audit("webbrowser.open", url)
            assert "'" not in url
            # hack for local urls
            if not ':' in url:
                url = 'file:'+url

# new must be 0 or 1
            new = int(bool(new))
            if self.name == "default":
                # User called open, open_new or get without a browser parameter
                script = 'open location "%s"' % url.replace('"', '%22') # opens in default browser
            else:
                # User called get and chose a browser
                if self.name == "OmniWeb":
                    toWindow = ""
                else:
                    # Include toWindow parameter of OpenURL command for browsers
                    # that support it.  0 == new window; -1 == existing
                    toWindow = "toWindow %d" % (new - 1)
                cmd = 'OpenURL "%s"' % url.replace('"', '%22')
                script = '''tell application "%s"
                                activate
                                %s %s
                            end tell''' % (self.name, cmd, toWindow)
            # Open pipe to AppleScript through osascript command
            osapipe = os.popen("osascript", "w")
            if osapipe is None:
                return False
            # Write script to osascript's stdin
            osapipe.write(script)
            rc = osapipe.close()
            return not rc

class MacOSXOSAScript(BaseBrowser):
        def __init__(self, name):
            self._name = name

def open(self, url, new=0, autoraise=True):
            if self._name == 'default':
                script = 'open location "%s"' % url.replace('"', '%22') # opens in default browser
            else:
                script = '''
                   tell application "%s"
                       activate
                       open location "%s"
                   end
                   '''%(self._name, url.replace('"', '%22'))

osapipe = os.popen("osascript", "w")
            if osapipe is None:
                return False

osapipe.write(script)
            rc = osapipe.close()
            return not rc

def main():
    import getopt
    usage = """Usage: %s [-n | -t] url
    -n: open new window
    -t: open new tab""" % sys.argv[0]
    try:
        opts, args = getopt.getopt(sys.argv[1:], 'ntd')
    except getopt.error as msg:
        print(msg, file=sys.stderr)
        print(usage, file=sys.stderr)
        sys.exit(1)
    new_win = 0
    for o, a in opts:
        if o == '-n': new_win = 1
        elif o == '-t': new_win = 2
    if len(args) != 1:
        print(usage, file=sys.stderr)
        sys.exit(1)

url = args[0]
    open(url, new_win)

print("\a")

if __name__ == "__main__":
    main()

cmd: