bazarr/libs/tzlocal/unix.py

165 lines
5.5 KiB
Python

import os
import pytz
import re
from tzlocal import utils
_cache_tz = None
def _tz_from_env(tzenv):
if tzenv[0] == ':':
tzenv = tzenv[1:]
# TZ specifies a file
if os.path.exists(tzenv):
with open(tzenv, 'rb') as tzfile:
return pytz.tzfile.build_tzinfo('local', tzfile)
# TZ specifies a zoneinfo zone.
try:
tz = pytz.timezone(tzenv)
# That worked, so we return this:
return tz
except pytz.UnknownTimeZoneError:
raise pytz.UnknownTimeZoneError(
"tzlocal() does not support non-zoneinfo timezones like %s. \n"
"Please use a timezone in the form of Continent/City")
def _try_tz_from_env():
tzenv = os.environ.get('TZ')
if tzenv:
try:
return _tz_from_env(tzenv)
except pytz.UnknownTimeZoneError:
pass
def _get_localzone(_root='/'):
"""Tries to find the local timezone configuration.
This method prefers finding the timezone name and passing that to pytz,
over passing in the localtime file, as in the later case the zoneinfo
name is unknown.
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."""
tzenv = _try_tz_from_env()
if tzenv:
return tzenv
# Now look for distribution specific configuration files
# that contain the timezone name.
for configfile in ('etc/timezone', 'var/db/zoneinfo'):
tzpath = os.path.join(_root, configfile)
try:
with open(tzpath, 'rb') as tzfile:
data = tzfile.read()
# Issue #3 was that /etc/timezone was a zoneinfo file.
# That's a misconfiguration, but we need to handle it gracefully:
if data[:5] == b'TZif2':
continue
etctz = data.strip().decode()
if not etctz:
# Empty file, skip
continue
for etctz in data.decode().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
return pytz.timezone(etctz.replace(' ', '_'))
except IOError:
# File doesn't exist or is a directory
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
return pytz.timezone(etctz.replace(' ', '_'))
except IOError:
# File doesn't exist or is a directory
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):
tzpath = os.path.realpath(tzpath)
start = tzpath.find("/")+1
while start is not 0:
tzpath = tzpath[start:]
try:
return pytz.timezone(tzpath)
except pytz.UnknownTimeZoneError:
pass
start = tzpath.find("/")+1
# Are we under Termux on Android? It's not officially supported, because
# there is no reasonable way to run tests for this, but let's make an effort.
if os.path.exists('/system/bin/getprop'):
import subprocess
androidtz = subprocess.check_output(['getprop', 'persist.sys.timezone'])
return pytz.timezone(androidtz.strip().decode())
# 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:
return pytz.tzfile.build_tzinfo('local', tzfile)
raise pytz.UnknownTimeZoneError('Can not find any timezone configuration')
def get_localzone():
"""Get the computers configured local timezone, if any."""
global _cache_tz
if _cache_tz is None:
_cache_tz = _get_localzone()
utils.assert_tz_offset(_cache_tz)
return _cache_tz
def reload_localzone():
"""Reload the cached localzone. You need to call this if the timezone has changed."""
global _cache_tz
_cache_tz = _get_localzone()
utils.assert_tz_offset(_cache_tz)
return _cache_tz