[Golang] Calculate Directory Size Excluding Sub-Directories

Calculate total size of files in directory, excluding sub-directories. We use ioutil.ReadDir to read information of files in directory, and calculate the sum of size of all files.

import (
      "io/ioutil"
      "os"
)

func calculateDirSize(dirpath string) (dirsize int64, err error) {
      err = os.Chdir(dirpath)
      if err != nil {
              return
      }
      files, err := ioutil.ReadDir(".")
      if err != nil {
              return
      }

      for _, file := range files {
              if file.Mode().IsRegular() {
                      dirsize += file.Size()
              }
      }
      return
}

Tested on: Ubuntu Linux 17.10, Go 1.10

References:

[1]	ioutil - The Go Programming Language