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[gotai64n.git] / cmd / tai64nlocal / main.go

diff --git a/cmd/tai64nlocal/main.go b/cmd/tai64nlocal/main.go
index 571c30ac8ffe87271312af27bbc130b685ea085e..4fa1926bc1c700c7edb6f8cd0f6e4ff5ba4f86df 100644 (file)
--- a/cmd/tai64nlocal/main.go
+++ b/cmd/tai64nlocal/main.go
@@ -1,34 +1,53 @@
-/*
-go.cypherpunks.ru/tai64n -- Pure Go TAI64N implementation
-Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, version 3 of the License.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
+// go.cypherpunks.ru/tai64n -- Pure Go TAI64/TAI64N implementation
+// Copyright (C) 2020-2024 Sergey Matveev <stargrave@stargrave.org>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 3 of the License.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 package main
 
 import (
        "bufio"
+       "flag"
+       "fmt"
        "log"
        "os"
        "strings"
        "time"
 
-       "go.cypherpunks.ru/tai64n"
+       "go.cypherpunks.ru/tai64n/v2"
 )
 
 func main() {
        log.SetFlags(0)
+       flag.Usage = func() {
+               fmt.Fprintf(
+                       flag.CommandLine.Output(),
+                       "Replace \"@HEX(TAI64)\"-prefixed line with human readable UTC.\n",
+               )
+               flag.PrintDefaults()
+       }
+       leapsecs := flag.Bool("leapsecs", false, "Take leap seconds into account: honest TAI->UTC")
+       db := flag.String("leapsecsdb", "", "Use that leapsecs.dat leap seconds database")
+       flag.Parse()
+
+       if *db != "" {
+               buf, err := os.ReadFile(*db)
+               if err != nil {
+                       log.Fatalln(err)
+               }
+               tai64n.LeapsecsDBLoad(buf)
+       }
+
        scanner := bufio.NewScanner(os.Stdin)
        var err error
        var s string
@@ -44,15 +63,20 @@ func main() {
                s = scanner.Text()
                if s[0] != '@' {
                        os.Stdout.WriteString(s + "\n")
+                       continue
                }
                sep = strings.IndexByte(s, byte(' '))
                if sep == -1 {
                        os.Stdout.WriteString(s + "\n")
+                       continue
                }
                t, err = tai64n.Decode(s[1:sep])
                if err != nil {
                        log.Fatalln(err)
                }
+               if *leapsecs {
+                       t = tai64n.LeapsecsSub(t)
+               }
                os.Stdout.WriteString(t.Format(tai64n.LocalFmt) + s[sep:] + "\n")
        }
 }