in core/shelllib.py [0:0]
def _shell_expand_str(value):
value = _re_variable.sub(r"${\1}", value)
value = _re_subshell.sub(_repl_subshell, value)
value = _re_variable2.sub(_repl_env_var, value)
value = _re_escaped_dollar.sub(r"$", value)
value = _re_escaped_slash.sub(r"\\", value)
return value