timeparsefilter.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"time"
	"strconv"
	"strings"
)

func main() {

	scanner := bufio.NewScanner(os.Stdin)

	for scanner.Scan() {
		line  := scanner.Text()
		// fmt.Printf("Line: %q\n", line)
		sp := strings.IndexByte(line, '\t')
		if sp > -1 {
			fpsec, err := strconv.ParseFloat(string(line[0:sp]), 10)
			if err != nil {
				fmt.Printf("%s\n", err)
				continue
			}
			sec := int64(fpsec)
			nsec := int64((fpsec - float64(sec))*1000000000.)
			t := time.Unix(sec, nsec)
			fmt.Printf("%s\t%s\n", line, string(t.Format("2006-01-02T03:04:05.000-0700")))
			// fmt.Printf("%f\t%d\t%d\t%s\n", fpsec, sec, nsec, string(t.Format("2006-01-02T03:04:05.000-0700")))
		}
	}
}