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 darwin freebsd linux netbsd openbsd 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), http://en.wikipedia.org/wiki/Zoneinfo, 10// and ftp://munnari.oz.au/pub/oldtz/ 11 12package time 13 14import ( 15 "errors" 16 "runtime" 17 "syscall" 18) 19 20func initTestingZone() { 21 syscall.Setenv("TZ", "America/Los_Angeles") 22 initLocal() 23} 24 25// Many systems use /usr/share/zoneinfo, Solaris 2 has 26// /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ. 27var zoneDirs = []string{ 28 "/usr/share/zoneinfo/", 29 "/usr/share/lib/zoneinfo/", 30 "/usr/lib/locale/TZ/", 31 runtime.GOROOT() + "/lib/time/zoneinfo/", 32} 33 34func initLocal() { 35 // consult $TZ to find the time zone to use. 36 // no $TZ means use the system default /etc/localtime. 37 // $TZ="" means use UTC. 38 // $TZ="foo" means use /usr/share/zoneinfo/foo. 39 40 tz, ok := syscall.Getenv("TZ") 41 switch { 42 case !ok: 43 z, err := loadZoneFile("", "/etc/localtime") 44 if err == nil { 45 localLoc = *z 46 localLoc.name = "Local" 47 return 48 } 49 case tz != "" && tz != "UTC": 50 if z, err := loadLocation(tz); err == nil { 51 localLoc = *z 52 return 53 } 54 } 55 56 // Fall back to UTC. 57 localLoc.name = "UTC" 58} 59 60func loadLocation(name string) (*Location, error) { 61 for _, zoneDir := range zoneDirs { 62 if z, err := loadZoneFile(zoneDir, name); err == nil { 63 z.name = name 64 return z, nil 65 } 66 } 67 return nil, errors.New("unknown time zone " + name) 68} 69