def shlex_quote(s):
    """Return a shell-escaped version of the string *s*.

    Backported from Python 3.3 standard library module shlex.
    """
    if not s:
        return "''"
    if _find_unsafe(s) is None:
        return s

    # use single quotes, and put single quotes into double quotes
    # the string $'b is then quoted as '$'"'"'b'
    return "'" + s.replace("'", "'\"'\"'") + "'"
Return a shell-escaped version of the string *s*.

    Backported from Python 3.3 standard library module shlex.
    
src/livestreamer_cli/compat.py