Golang : Find file size(disk usage) with filepath.Walk

Need to determine which file is taking up all the disk space? Maybe this small Golang program can be useful to you. The purpose of this small Golang program is to find out how much space a file occupies in a given target directory.

 package main

 import (
 "fmt"
 "os"
 )

 // function to return the disk usage information

 func diskUsage(currentPath string, info os.FileInfo) int64 {
 size := info.Size()

 if !info.IsDir() {
 return size
 }

 dir, err := os.Open(currentPath)

 if err != nil {
 fmt.Println(err)
 return size
 }
 defer dir.Close()

 files, err := dir.Readdir(-1)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 for _, file := range files {
 if file.Name() == "." || file.Name() == ".." {
 continue
 }
 size += diskUsage(currentPath+"/"+file.Name(), file)
 }

 fmt.Printf("Size in bytes : [%d] : [%s]\n", size, currentPath)

 return size
 }

 func main() {

 if len(os.Args) != 2 {
 fmt.Printf("USAGE : %s <target_directory> \n", os.Args[0])
 os.Exit(0)
 }

 dir := os.Args[1] // get the target directory

 info, err := os.Lstat(dir)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 diskUsage(dir, info)
 }

Sample output :

$ ./diskusage /Users/ | more

Size in bytes : [68] : [/Users//Shared/SC Info]

Size in bytes : [204] : [/Users//Shared]

Size in bytes : [139] : [/Users//sweetlogic/.atom/.apm]

Size in bytes : [402] : [/Users//sweetlogic/.atom/compile-cache/coffee]

Size in bytes : [895] : [/Users//sweetlogic/.atom/compile-cache/cson]