82 lines
2.7 KiB
Python
82 lines
2.7 KiB
Python
|
import sys
|
||
|
|
import os
|
||
|
|
import struct
|
||
|
|
from array import array
|
||
|
|
from collections import namedtuple
|
||
|
|
from datetime import datetime, timedelta
|
||
|
|
|
||
|
|
ttinfo = namedtuple('ttinfo', ['tt_gmtoff', 'tt_isdst', 'tt_abbrind'])
|
||
|
|
|
||
|
|
class TZInfo:
|
||
|
|
def __init__(self, transitions, type_indices, ttis, abbrs):
|
||
|
|
self.transitions = transitions
|
||
|
|
self.type_indices = type_indices
|
||
|
|
self.ttis = ttis
|
||
|
|
self.abbrs = abbrs
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def fromfile(cls, fileobj):
|
||
|
|
if fileobj.read(4).decode() != "TZif":
|
||
|
|
raise ValueError("not a zoneinfo file")
|
||
|
|
fileobj.seek(20)
|
||
|
|
header = fileobj.read(24)
|
||
|
|
tzh = (tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
|
||
|
|
tzh_timecnt, tzh_typecnt, tzh_charcnt) = struct.unpack(">6l", header)
|
||
|
|
transitions = array('i')
|
||
|
|
transitions.fromfile(fileobj, tzh_timecnt)
|
||
|
|
if sys.byteorder != 'big':
|
||
|
|
transitions.byteswap()
|
||
|
|
|
||
|
|
type_indices = array('B')
|
||
|
|
type_indices.fromfile(fileobj, tzh_timecnt)
|
||
|
|
|
||
|
|
ttis = []
|
||
|
|
for i in range(tzh_typecnt):
|
||
|
|
ttis.append(ttinfo._make(struct.unpack(">lbb", fileobj.read(6))))
|
||
|
|
|
||
|
|
abbrs = fileobj.read(tzh_charcnt)
|
||
|
|
|
||
|
|
self = cls(transitions, type_indices, ttis, abbrs)
|
||
|
|
self.tzh = tzh
|
||
|
|
|
||
|
|
return self
|
||
|
|
|
||
|
|
def dump(self, stream, start=None, end=None):
|
||
|
|
for j, (trans, i) in enumerate(zip(self.transitions, self.type_indices)):
|
||
|
|
utc = datetime.utcfromtimestamp(trans)
|
||
|
|
tti = self.ttis[i]
|
||
|
|
lmt = datetime.utcfromtimestamp(trans + tti.tt_gmtoff)
|
||
|
|
abbrind = tti.tt_abbrind
|
||
|
|
abbr = self.abbrs[abbrind:self.abbrs.find(0, abbrind)].decode()
|
||
|
|
if j > 0:
|
||
|
|
prev_tti = self.ttis[self.type_indices[j - 1]]
|
||
|
|
shift = " %+g" % ((tti.tt_gmtoff - prev_tti.tt_gmtoff) / 3600)
|
||
|
|
else:
|
||
|
|
shift = ''
|
||
|
|
print("%s UTC = %s %-5s isdst=%d" % (utc, lmt, abbr, tti[1]) + shift, file=stream)
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def zonelist(cls, zonedir='/usr/share/zoneinfo'):
|
||
|
|
zones = []
|
||
|
|
for root, _, files in os.walk(zonedir):
|
||
|
|
for f in files:
|
||
|
|
p = os.path.join(root, f)
|
||
|
|
with open(p, 'rb') as o:
|
||
|
|
magic = o.read(4)
|
||
|
|
if magic == b'TZif':
|
||
|
|
zones.append(p[len(zonedir) + 1:])
|
||
|
|
return zones
|
||
|
|
|
||
|
|
if __name__ == '__main__':
|
||
|
|
if len(sys.argv) < 2:
|
||
|
|
zones = TZInfo.zonelist()
|
||
|
|
for z in zones:
|
||
|
|
print(z)
|
||
|
|
sys.exit()
|
||
|
|
filepath = sys.argv[1]
|
||
|
|
if not filepath.startswith('/'):
|
||
|
|
filepath = os.path.join('/usr/share/zoneinfo', filepath)
|
||
|
|
with open(filepath, 'rb') as fileobj:
|
||
|
|
tzi = TZInfo.fromfile(fileobj)
|
||
|
|
tzi.dump(sys.stdout)
|