link helper files to given path

def helper(path):
    """
    link helper files to given path
    """
    if sys.platform.startswith("win"):
        # link batch files
        src_path = os.path.join(PHLB_BASE_DIR, "helper_cmd")
    elif sys.platform.startswith("linux"):
        # link shell scripts
        src_path = os.path.join(PHLB_BASE_DIR, "helper_sh")
    else:
        print("TODO: %s" % sys.platform)
        return

    if not os.path.isdir(src_path):
        raise RuntimeError("Helper script path not found here: '%s'" % src_path)

    for entry in scandir(src_path):
        print("_" * 79)
        print("Link file: '%s'" % entry.name)
        src = entry.path
        dst = os.path.join(path, entry.name)
        if os.path.exists(dst):
            print("Remove old file '%s'" % dst)
            try:
                os.remove(dst)
            except OSError as err:
                print("\nERROR:\n%s\n" % err)
                continue

        print("source.....: '%s'" % src)
        print("destination: '%s'" % dst)
        try:
            os.link(src, dst)
        except OSError as err:
            print("\nERROR:\n%s\n" % err)
            continue