Imported from /srv/lorry/lorry-area/swig-tarball/swig-1.3.40.tar.gz.HEADswig-1.3.40master

1 files changed, 233 insertions, 0 deletions

diff --git a/Examples/lua/embed2/embed2.c b/Examples/lua/embed2/embed2.c
new file mode 100644
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--- /dev/null
+++ b/Examples/lua/embed2/embed2.c
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+/* embed2.c some more test for an embeded interpreter

+ 

+This will go a bit further as it will pass values to and from the lua code.

+It uses less of the SWIG code, and more of the raw lua API's

+ 

+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 

+ 

+*/

+

+/* Deal with Microsoft's attempt at deprecating C standard runtime functions */

+#if !defined(SWIG_NO_CRT_SECURE_NO_DEPRECATE) && defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)

+# define _CRT_SECURE_NO_DEPRECATE

+#endif

+

+/* Deal with Microsoft's attempt at deprecating methods in the standard C++ library */

+#if !defined(SWIG_NO_SCL_SECURE_NO_DEPRECATE) && defined(_MSC_VER) && !defined(_SCL_SECURE_NO_DEPRECATE)

+# define _SCL_SECURE_NO_DEPRECATE

+#endif

+

+

+#include <stdlib.h>

+#include <stdio.h>

+

+#include <lua.h>

+#include <lauxlib.h>

+#include <lualib.h>

+#include <stdarg.h>

+#include <string.h>

+

+

+/* the SWIG wrappered library */

+extern int luaopen_example(lua_State*L);

+

+/* This is an example of how to call the Lua function

+    int add(int,int) 

+  its very tedious, but gives you an idea of the issues involded.

+  (look below for a better idea)

+*/

+int call_add(lua_State *L,int a,int b,int* res) {

+  int top;

+  /* ok, here we go:

+  push a, push b, call 'add' check & return res

+  */

+  top=lua_gettop(L);  /* for later */

+  lua_pushstring(L, "add");                                  /* function name */

+  lua_gettable(L, LUA_GLOBALSINDEX);               /* function to be called */

+  if (!lua_isfunction(L,-1)) {

+    printf("[C] error: cannot find function 'add'\n");

+    lua_settop(L,top);  // reset

+    return 0;

+  }

+  lua_pushnumber(L,a);

+  lua_pushnumber(L,b);

+  if (lua_pcall(L, 2, 1, 0) != 0)  /* call function with 2 arguments and 1 result */

+  {

+    printf("[C] error running function `add': %s\n",lua_tostring(L, -1));

+    lua_settop(L,top);  // reset

+    return 0;

+  }

+  // check results

+  if (!lua_isnumber(L,-1)) {

+    printf("[C] error: returned value is not a number\n");

+    lua_settop(L,top);  // reset

+    return 0;

+  }

+  *res=(int)lua_tonumber(L,-1);

+  lua_settop(L,top);  /* reset stack */

+  return 1;   // ok

+}

+

+/* This is a variargs call function for calling from C into Lua.

+Original Code from Programming in Lua (PIL) by Roberto Ierusalimschy

+ISBN 85-903798-1-7 

+http://www.lua.org/pil/25.3.html

+This has been modified slightly to make it compile, and its still a bit rough.

+But it gives the idea of how to make it work.

+*/

+int call_va (lua_State *L,const char *func, const char *sig, ...) {

+  va_list vl;

+  int narg, nres;  /* number of arguments and results */

+  int top;

+  top=lua_gettop(L);  /* for later */

+

+  va_start(vl, sig);

+  lua_getglobal(L, func);  /* get function */

+

+  /* push arguments */

+  narg = 0;

+  while (*sig) {  /* push arguments */

+    switch (*sig++) {

+

+    case 'd':  /* double argument */

+      lua_pushnumber(L, va_arg(vl, double));

+      break;

+

+    case 'i':  /* int argument */

+      lua_pushnumber(L, va_arg(vl, int));

+      break;

+

+    case 's':  /* string argument */

+      lua_pushstring(L, va_arg(vl, char *));

+      break;

+

+    case '>':

+      goto endwhile;

+

+    default:

+      printf("invalid option (%c)\n", *(sig - 1));

+      goto fail;

+    }

+    narg++;

+    /* do we need this?*/

+    /* luaL_checkstack(L, 1, "too many arguments"); */

+  }

+endwhile:

+

+  /* do the call */

+  nres = (int)strlen(sig);  /* number of expected results */

+  if (lua_pcall(L, narg, nres, 0) != 0)  /* do the call */

+  {

+    printf("error running function `%s': %s\n",func, lua_tostring(L, -1));

+    goto fail;

+  }

+

+  /* retrieve results */

+  nres = -nres;  /* stack index of first result */

+  while (*sig) {  /* get results */

+    switch (*sig++) {

+

+    case 'd':  /* double result */

+      if (!lua_isnumber(L, nres)) {

+        printf("wrong result type\n");

+        goto fail;

+      }

+      *va_arg(vl, double *) = lua_tonumber(L, nres);

+      break;

+

+    case 'i':  /* int result */

+      if (!lua_isnumber(L, nres)) {

+        printf("wrong result type\n");

+        goto fail;

+      }

+      *va_arg(vl, int *) = (int)lua_tonumber(L, nres);

+      break;

+

+    case 's':  /* string result */

+      if (!lua_isstring(L, nres)) {

+        printf("wrong result type\n");

+        goto fail;

+      }

+      strcpy(va_arg(vl, char *),lua_tostring(L, nres));/* WARNING possible buffer overflow */

+      break;

+

+    default: {

+        printf("invalid option (%c)", *(sig - 1));

+        goto fail;

+      }

+    }

+    nres++;

+  }

+  va_end(vl);

+

+  lua_settop(L,top);  /* reset stack */

+  return 1; /* ok */

+fail:

+  lua_settop(L,top);  /* reset stack */

+  return 0;   /* error */

+}

+

+int main(int argc,char* argv[]) {

+  lua_State *L;

+  int ok;

+  int res;

+  char str[80];

+  printf("[C] Welcome to the simple embedded Lua example v2\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 Lua function 'add(1,1)'\n");

+  printf("[C] using the C function 'call_add'\n");

+  ok=call_add(L,1,1,&res);

+  printf("[C] the function returned %d with value %d\n",ok,res);

+  printf("\n");

+  printf("[C] lets do this rather easier\n");

+  printf("[C] we will call the same Lua function using a generic C function 'call_va'\n");

+  ok=call_va(L,"add","ii>i",1,1,&res);

+  printf("[C] the function returned %d with value %d\n",ok,res);

+  printf("\n");

+  printf("[C] we will now use the same generic C function to call 'append(\"cat\",\"dog\")'\n");

+  ok=call_va(L,"append","ss>s","cat","dog",str);

+  printf("[C] the function returned %d with value %s\n",ok,str);

+  printf("\n");

+  printf("[C] we can also make some bad calls to ensure the code doesn't fail\n");

+  printf("[C] calling adds(1,2)\n");

+  ok=call_va(L,"adds","ii>i",1,2,&res);

+  printf("[C] the function returned %d with value %d\n",ok,res);

+  printf("[C] calling add(1,'fred')\n");

+  ok=call_va(L,"add","is>i",1,"fred",&res);

+  printf("[C] the function returned %d with value %d\n",ok,res);

+  printf("\n");

+  printf("[C] Note: no protection if you mess up the va-args, this is C\n");

+  printf("\n");

+  printf("[C] Finally we will call the wrappered gcd function gdc(6,9):\n");

+  printf("[C] This will pass the values to Lua, then call the wrappered function\n");

+  printf("    Which will get the values from Lua, call the C code \n");

+  printf("    and return the value to Lua and eventually back to C\n");

+  printf("[C] Certainly not the best way to do it :-)\n");

+  ok=call_va(L,"gcd","ii>i",6,9,&res);

+  printf("[C] the function returned %d with value %d\n",ok,res);

+  printf("\n");

+  printf("[C] all finished, closing the lua state\n");

+  lua_close(L);

+  return 0;

+}