Source file src/pkg/time/zoneinfo_unix.go
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 12 package time 13 14 import ( 15 "errors" 16 "runtime" 17 "syscall" 18 ) 19 20 func initTestingZone() { 21 z, err := loadZoneFile(runtime.GOROOT()+"/lib/time/zoneinfo.zip", "America/Los_Angeles") 22 if err != nil { 23 panic("cannot load America/Los_Angeles for testing: " + err.Error()) 24 } 25 z.name = "Local" 26 localLoc = *z 27 } 28 29 // Many systems use /usr/share/zoneinfo, Solaris 2 has 30 // /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ. 31 var zoneDirs = []string{ 32 "/usr/share/zoneinfo/", 33 "/usr/share/lib/zoneinfo/", 34 "/usr/lib/locale/TZ/", 35 runtime.GOROOT() + "/lib/time/zoneinfo/", 36 } 37 38 func initLocal() { 39 // consult $TZ to find the time zone to use. 40 // no $TZ means use the system default /etc/localtime. 41 // $TZ="" means use UTC. 42 // $TZ="foo" means use /usr/share/zoneinfo/foo. 43 44 tz, ok := syscall.Getenv("TZ") 45 switch { 46 case !ok: 47 z, err := loadZoneFile("", "/etc/localtime") 48 if err == nil { 49 localLoc = *z 50 localLoc.name = "Local" 51 return 52 } 53 case tz != "" && tz != "UTC": 54 if z, err := loadLocation(tz); err == nil { 55 localLoc = *z 56 return 57 } 58 } 59 60 // Fall back to UTC. 61 localLoc.name = "UTC" 62 } 63 64 func loadLocation(name string) (*Location, error) { 65 for _, zoneDir := range zoneDirs { 66 if z, err := loadZoneFile(zoneDir, name); err == nil { 67 z.name = name 68 return z, nil 69 } 70 } 71 return nil, errors.New("unknown time zone " + name) 72 }