Question

My situation is that I’m using the Lua (C) API to execute a script held in a string.
I would like the user to be able to terminate the execution of the script (this is essential if the script contains an infinite loop), how can I do this?

lua_State *Lua = lua_open();
char * code;
// Initialisation code
luaL_dostring(L, code);

Answer 1

You can use a hook to callback to C every time lua executes a line of the script.
In this hook function you can check if the user wanted to quit, and call lua_error if they did.

static bool ms_quit = false;

void IWantToQuit()
{
    ms_quit = true;
}

void LineHookFunc(lua_State *L, lua_Debug *ar)
{
    if(ar.event == LUA_HOOKLINE)
        if(ms_quit == true)
            luaL_error(L, "Too Many Lines Error");
}
//...

lua_State *Lua = lua_open();
char * code;
// Initialisation code
lua_sethook(Lua, &LineHookFunc, LUA_MASKLINE, 0);
luaL_dostring(L, code);