Function exec_result 

pub fn exec_result(state: &mut LuaState, stat: i32) -> Result<usize, LuaError>

Push the result of a process-exit status onto the stack. Returns 3 values: success-bool-or-nil, exit-kind string, status code.

C: LUALIB_API int luaL_execresult(lua_State *L, int stat)