| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| //go:build aix || (darwin && !ios) || dragonfly || freebsd || hurd || (linux && !android) || netbsd || openbsd || solaris |
| |
| // Parse "zoneinfo" time zone file. |
| // This is a fairly standard file format used on OS X, Linux, BSD, Sun, and others. |
| // See tzfile(5), https://en.wikipedia.org/wiki/Zoneinfo, |
| // and ftp://munnari.oz.au/pub/oldtz/ |
| |
| package time |
| |
| import ( |
| "runtime" |
| "syscall" |
| ) |
| |
| // Many systems use /usr/share/zoneinfo, Solaris 2 has |
| // /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ. |
| var zoneSources = []string{ |
| "/usr/share/zoneinfo/", |
| "/usr/share/lib/zoneinfo/", |
| "/usr/lib/locale/TZ/", |
| runtime.GOROOT() + "/lib/time/zoneinfo.zip", |
| } |
| |
| func initLocal() { |
| // consult $TZ to find the time zone to use. |
| // no $TZ means use the system default /etc/localtime. |
| // $TZ="" means use UTC. |
| // $TZ="foo" or $TZ=":foo" if foo is an absolute path, then the file pointed |
| // by foo will be used to initialize timezone; otherwise, file |
| // /usr/share/zoneinfo/foo will be used. |
| |
| tz, ok := syscall.Getenv("TZ") |
| switch { |
| case !ok: |
| z, err := loadLocation("localtime", []string{"/etc"}) |
| if err == nil { |
| localLoc = *z |
| localLoc.name = "Local" |
| return |
| } |
| case tz != "": |
| if tz[0] == ':' { |
| tz = tz[1:] |
| } |
| if tz != "" && tz[0] == '/' { |
| if z, err := loadLocation(tz, []string{""}); err == nil { |
| localLoc = *z |
| if tz == "/etc/localtime" { |
| localLoc.name = "Local" |
| } else { |
| localLoc.name = tz |
| } |
| return |
| } |
| } else if tz != "" && tz != "UTC" { |
| if z, err := loadLocation(tz, zoneSources); err == nil { |
| localLoc = *z |
| return |
| } |
| } |
| } |
| |
| // Fall back to UTC. |
| localLoc.name = "UTC" |
| } |