Input from user in Luaj

Question

Recently found out about luaj, it is really cool that hey implemented lua in java. And now I am wondering how to get user input for io.read()

As I saw on GitHub, in Globals.java there is this code: public InputStream STDIN = null; So I tried

        Globals globals = JsePlatform.standardGlobals();
        globals.STDIN = System.in;
        globals.load(new JseBaseLib());
        globals.load(new PackageLib());
        globals.load(new OsLib());
        LuaValue chunk = globals.load("a=io.read(); print(a)");
        chunk.call();

But it did not work

Answer 1

Your code is supposed to work as-is. In fact, you shouldn't even have to do all of that; even just this is supposed to work:

        Globals globals = JsePlatform.standardGlobals();
        LuaValue chunk = globals.load("a=io.read(); print(a)");
        chunk.call();

The reason it's not working for you is that there was a bug in LuaJ 3.0.2, fixed by commit 14745ba76a10 ("Fix call io.read, file:read without params."). Unfortunately, no release has been made since that commit. You can either get the fix by building LuaJ from source (but this is nontrivial on modern systems; see pull request #113), or work around the problem by doing io.read('*l') instead of io.read().