5 files changed, 173 insertions, 0 deletions
diff --git a/Examples/lua/embed/Makefile b/Examples/lua/embed/Makefile
new file mode 100644
index 0000000..51d0e61
--- /dev/null
+++ b/Examples/lua/embed/Makefile
@@ -0,0 +1,18 @@
+TOP        = ../..
+SWIG       = $(TOP)/../preinst-swig
+TARGET     = embed
+SRCS      = example.c
+INTERFACE  = example.i
+LUA_INTERP = embed.c
+
+# this is a little different to normal as we have our own special interpreter
+# which we want to static link
+all::
+	$(MAKE) -f $(TOP)/Makefile $(SWIGLIB) SRCS='$(SRCS)' SWIG='$(SWIG)' \
+	SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='example.i' LUA_INTERP='$(LUA_INTERP)' lua_static
+
+clean::
+	$(MAKE) -f $(TOP)/Makefile lua_clean
+
+check: all
+
diff --git a/Examples/lua/embed/embed.c b/Examples/lua/embed/embed.c
new file mode 100644
index 0000000..55ea099
--- /dev/null
+++ b/Examples/lua/embed/embed.c
@@ -0,0 +1,85 @@
+/* embed.c a simple test for an embeded interpreter
+ 
+The idea is that we wrapper a few simple function (example.c)
+and write our own app to call it.
+ 
+What it will do is load the wrappered lib, load runme.lua and then call some functions.
+To make life easier, all the printf's have either [C] or [Lua] at the start
+so you can see where they are coming from.
+ 
+We will be using the luaL_dostring()/lua_dostring() function to call into lua 
+ 
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+/* the SWIG wrappered library */
+extern int luaopen_example(lua_State*L);
+
+/* a really simple way of calling lua from C
+ just give it a lua state & a string to execute
+Unfortunately lua keeps changing its API's.
+In lua 5.0.X its lua_dostring()
+In lua 5.1.X its luaL_dostring()
+so we have a few extra compiles
+*/
+int dostring(lua_State *L, char* str) {
+  int ok;
+#if (defined(LUA_VERSION_NUM) && (LUA_VERSION_NUM>=501))
+
+  ok=luaL_dostring(L,str);	/* looks like this is lua 5.1.X or later, good */
+#else
+
+  ok=lua_dostring(L,str);	/* might be lua 5.0.x, using lua_dostring */
+#endif
+
+  if (ok!=0)
+    printf("[C] ERROR in dostring: %s\n",lua_tostring(L,-1));
+  return ok;
+}
+
+
+int main(int argc,char* argv[]) {
+  lua_State *L;
+  int ok;
+  printf("[C] Welcome to the simple embedded lua example\n");
+  printf("[C] We are in C\n");
+  printf("[C] opening a lua state & loading the libraries\n");
+  L=lua_open();
+  luaopen_base(L);
+  luaopen_string(L);
+  luaopen_math(L);
+  printf("[C] now loading the SWIG wrappered library\n");
+  luaopen_example(L);
+  printf("[C] all looks ok\n");
+  printf("\n");
+  printf("[C] lets load the file 'runme.lua'\n");
+  printf("[C] any lua code in this file will be executed\n");
+  if (luaL_loadfile(L, "runme.lua") || lua_pcall(L, 0, 0, 0)) {
+    printf("[C] ERROR: cannot run lua file: %s",lua_tostring(L, -1));
+    exit(3);
+  }
+  printf("[C] We are now back in C, all looks ok\n");
+  printf("\n");
+  printf("[C] lets call the function 'do_tests()'\n");
+  ok=dostring(L,"do_tests()");
+  printf("[C] We are back in C, the dostring() function returned %d\n",ok);
+  printf("\n");
+  printf("[C] Lets call lua again, but create an error\n");
+  ok=dostring(L,"no_such_function()");
+  printf("[C] We are back in C, the dostring() function returned %d\n",ok);
+  printf("[C] it should also have returned 1 and printed an error message\n");
+  printf("\n");
+  printf("[C] Lets call lua again, calling the greeting function\n");
+  ok=dostring(L,"call_greeting()");
+  printf("[C] This was C=>Lua=>C (getting a bit complex)\n");
+  printf("\n");
+  printf("[C] all finished, closing the lua state\n");
+  lua_close(L);
+  return 0;
+}
diff --git a/Examples/lua/embed/example.c b/Examples/lua/embed/example.c
new file mode 100644
index 0000000..c6c6d7b
--- /dev/null
+++ b/Examples/lua/embed/example.c
@@ -0,0 +1,22 @@
+/* File : example.c */
+
+#include <stdio.h>
+
+/* A global variable */
+double Foo = 3.0;
+
+/* Compute the greatest common divisor of positive integers */
+int gcd(int x, int y) {
+  int g;
+  g = y;
+  while (x > 0) {
+    g = x;
+    x = y % x;
+    y = g;
+  }
+  return g;
+}
+
+void greeting() {
+  printf("Hello from the C function 'greeting'\n");
+}
diff --git a/Examples/lua/embed/example.i b/Examples/lua/embed/example.i
new file mode 100644
index 0000000..7784b8e
--- /dev/null
+++ b/Examples/lua/embed/example.i
@@ -0,0 +1,8 @@
+/* File : example.i */
+%module example
+
+%inline %{
+extern int    gcd(int x, int y);
+extern double Foo;
+extern void greeting();
+%}
+\ No newline at end of file
diff --git a/Examples/lua/embed/runme.lua b/Examples/lua/embed/runme.lua
new file mode 100644
index 0000000..e02fd1d
--- /dev/null
+++ b/Examples/lua/embed/runme.lua
@@ -0,0 +1,40 @@
+print "[lua] This is runme.lua"
+-- test program for embeded lua
+-- we do not need to load the library, as it was already in the intrepreter
+-- but lets check anyway
+assert(type(example)=='table',"Don't appear to have loaded the example module")
+
+-- a test function to run the tests
+function do_tests()
+	print("[lua] We are now in Lua, inside the do_tests() function")
+	print("[lua] We will be calling example.gcd() and changing example.Foo")
+	-- Call our gcd() function
+	x = 42
+	y = 105
+	g = example.gcd(x,y)
+	print("[lua] The gcd of",x,"and",y,"is",g)
+
+	-- Manipulate the Foo global variable
+
+	-- Output its current value
+	print("[lua] Foo = ", example.Foo)
+
+	-- Change its value
+	example.Foo = 3.1415926
+
+	-- See if the change took effect
+	print("[lua] Foo = ", example.Foo)
+	print("[lua] ending the do_tests() function")
+end
+
+function call_greeting()
+	print("[lua] We are now in Lua, inside the call_greeting() function")
+	example.greeting()
+	print("[lua] ending the call_greeting() function")
+end
+
+
+
+
+
+