files=[]
    for file in os.listdir(someDir):
        if file.endswith(".txt"):
        files.append(file)
    convert = lambda text: int(text) if text.isdigit() else text
    alphanum_key = lambda key: [ convert(c) for c in re.split('([0-9]+)',key) ]
    files.sort( key=alphanum_key )

    for i in files:
        print (i)

func main() {
        dirname := "someDir"
        d, err := os.Open(dirname)
        if err != nil {
            fmt.Println(err)
        }
        defer d.Close()
        fi, err := d.Readdir(-1)
        if err != nil {
            fmt.Println(err)
        }
        for _, fi := range fi {
            if fi.Mode().IsRegular() {
                fmt.Println(fi.Name())
            }
        }