Function switch_util_quote_shell_arg 

pub unsafe extern "C" fn switch_util_quote_shell_arg(
    string: *const c_char,
) -> *mut c_char

\brief Quote shell argument \param string the string to quote (example: a ’ b“’ c) \return the quoted string (gives: ’a ‘'’ b“‘'’ c’ for unices, “a ’ b ’ c” for MS Windows), should be freed