Golang : Determine if directory is empty with os.File.Readdir() function



Tags : golang empty-directory readdir filepath-walk

Problem :

You are traversing a directory tree with filepath.Walk() function and you need to find out if a directory is empty or not.

Solution :

Instead of grabbing the entire directory content only to find out that it is empty, check if the directory is empty by reading in 1 file. Yup, just 1 file with the os.Readdir() function and if the error returned is EOF(end of file), that means .... the directory is empty.

 package main

 import (
 "fmt"
 "io"
 "os"
 )

 func IsDirEmpty(name string) (bool, error) {
 f, err := os.Open(name)
 if err != nil {
 return false, err
 }
 defer f.Close()

 // read in ONLY one file
 _, err = f.Readdir(1)

 // and if the file is EOF... well, the dir is empty.
 if err == io.EOF {
 return true, nil
 }
 return false, err
 }

 func main() {
 ok, err := IsDirEmpty("./")

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

 fmt.Println("Current directory is empty? : ", ok)

 ok, err = IsDirEmpty("./emptydir")

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

 fmt.Println("EmptyDir directory is empty? : ", ok)

 }

Sample output :

Current directory is empty? : false

EmptyDir directory is empty? : true

References :

http://golang.org/pkg/os/#File.Readdir

https://www.socketloop.com/tutorials/golang-read-directory-content-with-filepath-walk

  See also : Golang : Delete certain files in a directory



Tags : golang empty-directory readdir filepath-walk

By Adam Ng

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