loadlib.c
(5.0.3)
/*
** $Id: loadlib.c,v 1.4 2003/04/07 20:11:53 roberto Exp $
** Dynamic library loader for Lua
** See Copyright Notice in lua.h
*
* This Lua library exports a single function, called loadlib, which is
* called from Lua as loadlib(lib,init), where lib is the full name of the
* library to be loaded (including the complete path) and init is the name
* of a function to be called after the library is loaded. Typically, this
* function will register other functions, thus making the complete library
* available to Lua. The init function is *not* automatically called by
* loadlib. Instead, loadlib returns the init function as a Lua function
* that the client can call when it thinks is appropriate. In the case of
* errors, loadlib returns nil and two strings describing the error.
* The first string is supplied by the operating system; it should be
* informative and useful for error messages. The second string is "open",
* "init", or "absent" to identify the error and is meant to be used for
* making decisions without having to look into the first string (whose
* format is system-dependent).
*
* This module contains an implementation of loadlib for Unix systems that
* have dlfcn, an implementation for Windows, and a stub for other systems.
* See the list at the end of this file for some links to available
* implementations of dlfcn and interfaces to other native dynamic loaders
* on top of which loadlib could be implemented.
*
*/
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
#undef LOADLIB
#ifdef USE_DLOPEN
#define LOADLIB
/*
* This is an implementation of loadlib based on the dlfcn interface.
* The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
* NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
* as an emulation layer on top of native functions.
*/
#include <dlfcn.h>
static int loadlib(lua_State *L)
{
const char *path=luaL_checkstring(L,1);
const char *init=luaL_checkstring(L,2);
void *lib=dlopen(path,RTLD_NOW);
if (lib!=NULL)
{
lua_CFunction f=(lua_CFunction) dlsym(lib,init);
if (f!=NULL)
{
lua_pushlightuserdata(L,lib);
lua_pushcclosure(L,f,1);
return 1;
}
}
/* else return appropriate error messages */
lua_pushnil(L);
lua_pushstring(L,dlerror());
lua_pushstring(L,(lib!=NULL) ? "init" : "open");
if (lib!=NULL) dlclose(lib);
return 3;
}
#endif
/*
** In Windows, default is to use dll; otherwise, default is not to use dll
*/
#ifndef USE_DLL
#ifdef _WIN32
#define USE_DLL 1
#else
#define USE_DLL 0
#endif
#endif
#if USE_DLL
#define LOADLIB
/*
* This is an implementation of loadlib for Windows using native functions.
*/
#include <windows.h>
static void pusherror(lua_State *L)
{
int error=GetLastError();
char buffer[128];
if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
0, error, 0, buffer, sizeof(buffer), 0))
lua_pushstring(L,buffer);
else
lua_pushfstring(L,"system error %d\n",error);
}
static int loadlib(lua_State *L)
{
const char *path=luaL_checkstring(L,1);
const char *init=luaL_checkstring(L,2);
HINSTANCE lib=LoadLibrary(path);
if (lib!=NULL)
{
lua_CFunction f=(lua_CFunction) GetProcAddress(lib,init);
if (f!=NULL)
{
lua_pushlightuserdata(L,lib);
lua_pushcclosure(L,f,1);
return 1;
}
}
lua_pushnil(L);
pusherror(L);
lua_pushstring(L,(lib!=NULL) ? "init" : "open");
if (lib!=NULL) FreeLibrary(lib);
return 3;
}
#endif
#ifndef LOADLIB
/* Fallback for other systems */
/*
** Those systems support dlopen, so they should have defined USE_DLOPEN.
** The default (no)implementation gives them a special error message.
*/
#ifdef linux
#define LOADLIB
#endif
#ifdef sun
#define LOADLIB
#endif
#ifdef sgi
#define LOADLIB
#endif
#ifdef BSD
#define LOADLIB
#endif
#ifdef _WIN32
#define LOADLIB
#endif
#ifdef LOADLIB
#undef LOADLIB
#define LOADLIB "`loadlib' not installed (check your Lua configuration)"
#else
#define LOADLIB "`loadlib' not supported"
#endif
static int loadlib(lua_State *L)
{
lua_pushnil(L);
lua_pushliteral(L,LOADLIB);
lua_pushliteral(L,"absent");
return 3;
}
#endif
LUALIB_API int luaopen_loadlib (lua_State *L)
{
lua_register(L,"loadlib",loadlib);
return 0;
}
/*
* Here are some links to available implementations of dlfcn and
* interfaces to other native dynamic loaders on top of which loadlib
* could be implemented. Please send contributions and corrections to us.
*
* AIX
* Starting with AIX 4.2, dlfcn is included in the base OS.
* There is also an emulation package available.
* http://www.faqs.org/faqs/aix-faq/part4/section-21.html
*
* HPUX
* HPUX 11 has dlfcn. For HPUX 10 use shl_*.
* http://www.geda.seul.org/mailinglist/geda-dev37/msg00094.html
* http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html
*
* Macintosh, Windows
* http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html
*
* Mac OS X/Darwin
* http://www.opendarwin.org/projects/dlcompat/
*
* GLIB has wrapper code for BeOS, OS2, Unix and Windows
* http://cvs.gnome.org/lxr/source/glib/gmodule/
*
*/