added two lua tutorials

git-svn-id: svn://anubis/misc/lua@130 bd8a9e45-a331-0410-811e-c64571078777

tut/Makefile

@@ -0,0 +1,9 @@
+
+TARGET := tut
+CPPFLAGS := -I/usr/include/lua5.1
+LDFLAGS  := -llua5.1
+
+all: $(TARGET)
+
+$(TARGET): $(TARGET).cc
+	$(CXX) -o $@ $(CPPFLAGS) $(CXXFLAGS) $^ $(LDFLAGS)

tut/hello_world.lua

@@ -0,0 +1,3 @@
+
+-- The first program in every language
+io.write("Hello world, from", _VERSION, "!\n")

tut/tut.cc

@@ -0,0 +1,48 @@
+
+#include <iostream>
+#include <lua.hpp>
+using namespace std;
+
+void report_errors(lua_State * L, int status)
+{
+    if ( status != 0 )
+    {
+        cerr << "-- " << lua_tostring(L, -1) << endl;
+        lua_pop(L, 1); // remove error message
+    }
+}
+
+int main(int argc, char ** argv)
+{
+    for ( int n = 1; n < argc; ++n )
+    {
+        const char * file = argv[n];
+
+        lua_State * L = lua_open();
+
+        luaL_openlibs(L);
+#if 0
+        luaopen_io(L);              // provides io.*
+        luaopen_base(L);
+        luaopen_table(L);
+        luaopen_string(L);
+        luaopen_math(L);
+#endif
+
+        cerr << "-- Loading file: " << file << endl;
+
+        int s = luaL_loadfile(L, file);
+
+        if ( s == 0 )
+        {
+            // execute Lua program
+            s = lua_pcall(L, 0, LUA_MULTRET, 0);
+        }
+
+        report_errors(L, s);
+        lua_close(L);
+        cerr << endl;
+    }
+
+    return 0;
+}