first version of `loadlib'

Tekenlight · Mar 17, 2003 · b0c40e2 · b0c40e2
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diff --git a/loadlib.c b/loadlib.c
@@ -0,0  1,173 @@
 /*
 ** $Id$
 ** Bare-bones 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 bare-bones loadlib  function is supposed to be used  as a foundation
 * for  more sophisticated  dynamic library  loaders, possibly  still called
 * loadlib and probably written in Lua, that  will be smart enough to try to
 * find the library in different directories and also perhaps guess the name
 * of the init function.
 *
 * 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"
 
 #ifndef USE_LOADLIB
 #define USE_LOADLIB 1
 #endif
 
 #ifndef USE_DLOPEN
 #define USE_DLOPEN 0
 #endif
 
 #if USE_LOADLIB
 
 #if defined(linux) || defined(sun) || defined(sgi) || defined(BSD) || 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;
   }
  }
  lua_pushnil(L);
  lua_pushstring(L,dlerror());
  lua_pushstring(L,(lib!=NULL) ? "init" : "open");
  if (lib!=NULL) dlclose(lib);
  return 3;
 }
 
 #elif defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
 #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("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;
 }
 
 #else
 /*
 * write an implementation for your system  here and send it to us, together
 * with preprocessing symbols that identify your system.
 */
 #endif
 #endif
 
 #ifndef LOADLIB
 /* Fallback for other systems */
 
 static int loadlib(lua_State *L)
 {
  lua_pushnil(L);
  lua_pushliteral(L,"`loadlib' not supported");
  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  por  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/
 *
 */
diff --git a/lualib.h b/lualib.h
@@ -1,5  1,5 @@
 /*
-** $Id: lualib.h,v 1.25 2002/07/09 18:49:13 roberto Exp roberto $
 ** $Id: lualib.h,v 1.26 2003/03/11 12:24:34 roberto Exp roberto $
 ** Lua standard libraries
 ** See Copyright Notice in lua.h
 */
@@ -36,6  36,9 @@ LUALIB_API int luaopen_math (lua_State *L);
 LUALIB_API int luaopen_debug (lua_State *L);
 
 
 LUALIB_API int luaopen_loadlib (lua_State *L);
 
 
 /* to help testing the libraries */
 #ifndef lua_assert
 #define lua_assert(c)		/* empty */