bazarr/libs/tzlocal/unix.py

216 lines
7.3 KiB
Python

import os
import re
import sys
import warnings
from datetime import timezone
import pytz_deprecation_shim as pds
from tzlocal import utils
if sys.version_info >= (3, 9):
from zoneinfo import ZoneInfo # pragma: no cover
else:
from backports.zoneinfo import ZoneInfo # pragma: no cover
_cache_tz = None
_cache_tz_name = None
def _get_localzone_name(_root="/"):
"""Tries to find the local timezone configuration.
This method finds the timezone name, if it can, or it returns None.
The parameter _root makes the function look for files like /etc/localtime
beneath the _root directory. This is primarily used by the tests.
In normal usage you call the function without parameters."""
# First try the ENV setting.
tzenv = utils._tz_name_from_env()
if tzenv:
return tzenv
# Are we under Termux on Android?
if os.path.exists(os.path.join(_root, "system/bin/getprop")):
import subprocess
androidtz = (
subprocess.check_output(["getprop", "persist.sys.timezone"])
.strip()
.decode()
)
return androidtz
# Now look for distribution specific configuration files
# that contain the timezone name.
# Stick all of them in a dict, to compare later.
found_configs = {}
for configfile in ("etc/timezone", "var/db/zoneinfo"):
tzpath = os.path.join(_root, configfile)
try:
with open(tzpath, "rt") as tzfile:
data = tzfile.read()
etctz = data.strip('/ \t\r\n')
if not etctz:
# Empty file, skip
continue
for etctz in etctz.splitlines():
# Get rid of host definitions and comments:
if " " in etctz:
etctz, dummy = etctz.split(" ", 1)
if "#" in etctz:
etctz, dummy = etctz.split("#", 1)
if not etctz:
continue
found_configs[tzpath] = etctz.replace(" ", "_")
except (IOError, UnicodeDecodeError):
# File doesn't exist or is a directory, or it's a binary file.
continue
# CentOS has a ZONE setting in /etc/sysconfig/clock,
# OpenSUSE has a TIMEZONE setting in /etc/sysconfig/clock and
# Gentoo has a TIMEZONE setting in /etc/conf.d/clock
# We look through these files for a timezone:
zone_re = re.compile(r"\s*ZONE\s*=\s*\"")
timezone_re = re.compile(r"\s*TIMEZONE\s*=\s*\"")
end_re = re.compile('"')
for filename in ("etc/sysconfig/clock", "etc/conf.d/clock"):
tzpath = os.path.join(_root, filename)
try:
with open(tzpath, "rt") as tzfile:
data = tzfile.readlines()
for line in data:
# Look for the ZONE= setting.
match = zone_re.match(line)
if match is None:
# No ZONE= setting. Look for the TIMEZONE= setting.
match = timezone_re.match(line)
if match is not None:
# Some setting existed
line = line[match.end():]
etctz = line[: end_re.search(line).start()]
# We found a timezone
found_configs[tzpath] = etctz.replace(" ", "_")
except (IOError, UnicodeDecodeError):
# UnicodeDecode handles when clock is symlink to /etc/localtime
continue
# systemd distributions use symlinks that include the zone name,
# see manpage of localtime(5) and timedatectl(1)
tzpath = os.path.join(_root, "etc/localtime")
if os.path.exists(tzpath) and os.path.islink(tzpath):
etctz = realtzpath = os.path.realpath(tzpath)
start = etctz.find("/") + 1
while start != 0:
etctz = etctz[start:]
try:
pds.timezone(etctz)
tzinfo = f"{tzpath} is a symlink to"
found_configs[tzinfo] = etctz.replace(" ", "_")
except pds.UnknownTimeZoneError:
pass
start = etctz.find("/") + 1
if len(found_configs) > 0:
# We found some explicit config of some sort!
if len(found_configs) > 1:
# Uh-oh, multiple configs. See if they match:
unique_tzs = set()
zoneinfo = os.path.join(_root, "usr", "share", "zoneinfo")
directory_depth = len(zoneinfo.split(os.path.sep))
for tzname in found_configs.values():
# Look them up in /usr/share/zoneinfo, and find what they
# really point to:
path = os.path.realpath(os.path.join(zoneinfo, *tzname.split("/")))
real_zone_name = "/".join(path.split(os.path.sep)[directory_depth:])
unique_tzs.add(real_zone_name)
if len(unique_tzs) != 1:
message = "Multiple conflicting time zone configurations found:\n"
for key, value in found_configs.items():
message += f"{key}: {value}\n"
message += "Fix the configuration, or set the time zone in a TZ environment variable.\n"
raise utils.ZoneInfoNotFoundError(message)
# We found exactly one config! Use it.
return list(found_configs.values())[0]
def _get_localzone(_root="/"):
"""Creates a timezone object from the timezone name.
If there is no timezone config, it will try to create a file from the
localtime timezone, and if there isn't one, it will default to UTC.
The parameter _root makes the function look for files like /etc/localtime
beneath the _root directory. This is primarily used by the tests.
In normal usage you call the function without parameters."""
# First try the ENV setting.
tzenv = utils._tz_from_env()
if tzenv:
return tzenv
tzname = _get_localzone_name(_root)
if tzname is None:
# No explicit setting existed. Use localtime
for filename in ("etc/localtime", "usr/local/etc/localtime"):
tzpath = os.path.join(_root, filename)
if not os.path.exists(tzpath):
continue
with open(tzpath, "rb") as tzfile:
tz = pds.wrap_zone(ZoneInfo.from_file(tzfile, key="local"))
break
else:
warnings.warn("Can not find any timezone configuration, defaulting to UTC.")
tz = timezone.utc
else:
tz = pds.timezone(tzname)
if _root == "/":
# We are using a file in etc to name the timezone.
# Verify that the timezone specified there is actually used:
utils.assert_tz_offset(tz)
return tz
def get_localzone_name():
"""Get the computers configured local timezone name, if any."""
global _cache_tz_name
if _cache_tz_name is None:
_cache_tz_name = _get_localzone_name()
return _cache_tz_name
def get_localzone():
"""Get the computers configured local timezone, if any."""
global _cache_tz
if _cache_tz is None:
_cache_tz = _get_localzone()
return _cache_tz
def reload_localzone():
"""Reload the cached localzone. You need to call this if the timezone has changed."""
global _cache_tz_name
global _cache_tz
_cache_tz_name = _get_localzone_name()
_cache_tz = _get_localzone()
return _cache_tz