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 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 12 package time 13 14 import ( 15 "syscall" 16 ) 17 18 // Many systems use /usr/share/zoneinfo, Solaris 2 has 19 // /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ. 20 var zoneSources = []string{ 21 "/usr/share/zoneinfo/", 22 "/usr/share/lib/zoneinfo/", 23 "/usr/lib/locale/TZ/", 24 } 25 26 func initLocal() { 27 // consult $TZ to find the time zone to use. 28 // no $TZ means use the system default /etc/localtime. 29 // $TZ="" means use UTC. 30 // $TZ="foo" means use /usr/share/zoneinfo/foo. 31 32 tz, ok := syscall.Getenv("TZ") 33 switch { 34 case !ok: 35 z, err := loadLocation("localtime", []string{"/etc/"}) 36 if err == nil { 37 localLoc = *z 38 localLoc.name = "Local" 39 return 40 } 41 case tz != "" && tz != "UTC": 42 if z, err := loadLocation(tz, zoneSources); err == nil { 43 localLoc = *z 44 return 45 } 46 } 47 48 // Fall back to UTC. 49 localLoc.name = "UTC" 50 } 51