Golang : Change a file last modified date and time

There are times when we need to perform some operation on a file, but then manually change the last modified and access time of the file.

In this tutorial, we will learn how to change a file last modified time with http://golang.org/pkg/os/#Chtimes function. The Chtimes will require the target filename, atime and mtime.

• atime: time of last access (ls -lu),
• mtime: time of last modification (ls -l)

Below the the code example :

changetime.go

 package main

 import (
 "fmt"
 "os"
 "time"
 )


 func main() {

 filename := "binary.file"

 // get last modified time
 file, err := os.Stat(filename)

 if err != nil {
 fmt.Println(err)
 }

 modifiedtime := file.ModTime()

 fmt.Println("Last modified time : ", modifiedtime)

 // get current timestamp

 currenttime := time.Now().Local()

 fmt.Println("Current time : ", currenttime.Format("2006-01-02 15:04:05 +0800"))

 // change both atime and mtime to currenttime

 err = os.Chtimes(filename, currenttime, currenttime)

 if err != nil {
 fmt.Println(err)
 }

 fmt.Println("Changed the file time information")
 }

Result :

 localhost:~ admin$ go run changetime.go
 Last modified time :  2014-02-12 22:00:18 +0800 MYT <------ original last modified time
 Current time :  2014-06-30 14:50:00 +0800
 Changed the file time information
 localhost:~ admin$ ls -la binary.file
 -rwxr-xr-x  1 admin  staff  2206048 Jun 30 14:50 binary.file  <------- changed to Jun 30