1// Copyright 2009 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// +build aix darwin,386 darwin,amd64 dragonfly freebsd hurd js,wasm linux,!android nacl netbsd openbsd solaris 6 7// Parse "zoneinfo" time zone file. 8// This is a fairly standard file format used on OS X, Linux, BSD, Sun, and others. 9// See tzfile(5), https://en.wikipedia.org/wiki/Zoneinfo, 10// and ftp://munnari.oz.au/pub/oldtz/ 11 12package time 13 14import ( 15 "runtime" 16 "syscall" 17) 18 19// Many systems use /usr/share/zoneinfo, Solaris 2 has 20// /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ. 21var zoneSources = []string{ 22 "/usr/share/zoneinfo/", 23 "/usr/share/lib/zoneinfo/", 24 "/usr/lib/locale/TZ/", 25 runtime.GOROOT() + "/lib/time/zoneinfo.zip", 26} 27 28func initLocal() { 29 // consult $TZ to find the time zone to use. 30 // no $TZ means use the system default /etc/localtime. 31 // $TZ="" means use UTC. 32 // $TZ="foo" means use /usr/share/zoneinfo/foo. 33 34 tz, ok := syscall.Getenv("TZ") 35 switch { 36 case !ok: 37 z, err := loadLocation("localtime", []string{"/etc/"}) 38 if err == nil { 39 localLoc = *z 40 localLoc.name = "Local" 41 return 42 } 43 case tz != "" && tz != "UTC": 44 if z, err := loadLocation(tz, zoneSources); err == nil { 45 localLoc = *z 46 return 47 } 48 } 49 50 // Fall back to UTC. 51 localLoc.name = "UTC" 52} 53