func getFiles(dirPath string) ([]string, error) {
    // check if dirPath ends with "/"
    if !strings.HasSuffix(dirPath, "/") {
        dirPath += "/"
    }

    files, err := ioutil.ReadDir(dirPath)
    if err != nil {
        return nil, err
    }

    var fileNames []string

    for _, f := range files {
        if f.IsDir() {
            continue
        }
        fileNames = append(fileNames, f.Name())
    }

    return fileNames, nil
}