patch: fmt, os, runtime, syscall, time

internal/lib/time/zoneinfo_unix.go

@@ -0,0 +1,69 @@
+// 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 unix && !ios && !android
+
+// 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 (
+	"syscall"
+)
+
+// Many systems use /usr/share/zoneinfo, Solaris 2 has
+// /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ,
+// NixOS has /etc/zoneinfo.
+var platformZoneSources = []string{
+	"/usr/share/zoneinfo/",
+	"/usr/share/lib/zoneinfo/",
+	"/usr/lib/locale/TZ/",
+	"/etc/zoneinfo",
+}
+
+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, platformZoneSources); err == nil {
+				localLoc = *z
+				return
+			}
+		}
+	}
+
+	// Fall back to UTC.
+	localLoc.name = "UTC"
+}