1/*
2** $Id: loadlib.c $
3** Dynamic library loader for Lua
4** See Copyright Notice in lua.h
5**
6** This module contains an implementation of loadlib for Unix systems
7** that have dlfcn, an implementation for Windows, and a stub for other
8** systems.
9*/
10
11#define loadlib_c
12#define LUA_LIB
13
14#include "lprefix.h"
15
16
17#include <stdio.h>
18#include <stdlib.h>
19#include <string.h>
20
21#include "lua.h"
22
23#include "lauxlib.h"
24#include "lualib.h"
25
26
27/*
28** LUA_IGMARK is a mark to ignore all before it when building the
29** luaopen_ function name.
30*/
31#if !defined (LUA_IGMARK)
32#define LUA_IGMARK "-"
33#endif
34
35
36/*
37** LUA_CSUBSEP is the character that replaces dots in submodule names
38** when searching for a C loader.
39** LUA_LSUBSEP is the character that replaces dots in submodule names
40** when searching for a Lua loader.
41*/
42#if !defined(LUA_CSUBSEP)
43#define LUA_CSUBSEP LUA_DIRSEP
44#endif
45
46#if !defined(LUA_LSUBSEP)
47#define LUA_LSUBSEP LUA_DIRSEP
48#endif
49
50
51/* prefix for open functions in C libraries */
52#define LUA_POF "luaopen_"
53
54/* separator for open functions in C libraries */
55#define LUA_OFSEP "_"
56
57
58/*
59** key for table in the registry that keeps handles
60** for all loaded C libraries
61*/
62static const char *const CLIBS = "_CLIBS";
63
64#define LIB_FAIL "open"
65
66
67#define setprogdir(L) ((void)0)
68
69
70/*
71** Special type equivalent to '(void*)' for functions in gcc
72** (to suppress warnings when converting function pointers)
73*/
74typedef void (*voidf)(void);
75
76
77/*
78** system-dependent functions
79*/
80
81/*
82** unload library 'lib'
83*/
84static void lsys_unloadlib (void *lib);
85
86/*
87** load C library in file 'path'. If 'seeglb', load with all names in
88** the library global.
89** Returns the library; in case of error, returns NULL plus an
90** error string in the stack.
91*/
92static void *lsys_load (lua_State *L, const char *path, int seeglb);
93
94/*
95** Try to find a function named 'sym' in library 'lib'.
96** Returns the function; in case of error, returns NULL plus an
97** error string in the stack.
98*/
99static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
100
101
102
103
104#if defined(LUA_USE_DLOPEN) /* { */
105/*
106** {========================================================================
107** This is an implementation of loadlib based on the dlfcn interface.
108** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
109** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
110** as an emulation layer on top of native functions.
111** =========================================================================
112*/
113
114#include <dlfcn.h>
115
116/*
117** Macro to convert pointer-to-void* to pointer-to-function. This cast
118** is undefined according to ISO C, but POSIX assumes that it works.
119** (The '__extension__' in gnu compilers is only to avoid warnings.)
120*/
121#if defined(__GNUC__)
122#define cast_func(p) (__extension__ (lua_CFunction)(p))
123#else
124#define cast_func(p) ((lua_CFunction)(p))
125#endif
126
127
128static void lsys_unloadlib (void *lib) {
129 dlclose(lib);
130}
131
132
133static void *lsys_load (lua_State *L, const char *path, int seeglb) {
134 void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
135 if (l_unlikely(lib == NULL))
136 lua_pushstring(L, dlerror());
137 return lib;
138}
139
140
141static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
142 lua_CFunction f = cast_func(dlsym(lib, sym));
143 if (l_unlikely(f == NULL))
144 lua_pushstring(L, dlerror());
145 return f;
146}
147
148/* }====================================================== */
149
150
151
152#elif defined(LUA_DL_DLL) /* }{ */
153/*
154** {======================================================================
155** This is an implementation of loadlib for Windows using native functions.
156** =======================================================================
157*/
158
159#include <windows.h>
160
161
162/*
163** optional flags for LoadLibraryEx
164*/
165#if !defined(LUA_LLE_FLAGS)
166#define LUA_LLE_FLAGS 0
167#endif
168
169
170#undef setprogdir
171
172
173/*
174** Replace in the path (on the top of the stack) any occurrence
175** of LUA_EXEC_DIR with the executable's path.
176*/
177static void setprogdir (lua_State *L) {
178 char buff[MAX_PATH + 1];
179 char *lb;
180 DWORD nsize = sizeof(buff)/sizeof(char);
181 DWORD n = GetModuleFileNameA(NULL, buff, nsize); /* get exec. name */
182 if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
183 luaL_error(L, "unable to get ModuleFileName");
184 else {
185 *lb = '\0'; /* cut name on the last '\\' to get the path */
186 luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
187 lua_remove(L, -2); /* remove original string */
188 }
189}
190
191
192
193
194static void pusherror (lua_State *L) {
195 int error = GetLastError();
196 char buffer[128];
197 if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
198 NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
199 lua_pushstring(L, buffer);
200 else
201 lua_pushfstring(L, "system error %d\n", error);
202}
203
204static void lsys_unloadlib (void *lib) {
205 FreeLibrary((HMODULE)lib);
206}
207
208
209static void *lsys_load (lua_State *L, const char *path, int seeglb) {
210 HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
211 (void)(seeglb); /* not used: symbols are 'global' by default */
212 if (lib == NULL) pusherror(L);
213 return lib;
214}
215
216
217static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
218 lua_CFunction f = (lua_CFunction)(voidf)GetProcAddress((HMODULE)lib, sym);
219 if (f == NULL) pusherror(L);
220 return f;
221}
222
223/* }====================================================== */
224
225
226#else /* }{ */
227/*
228** {======================================================
229** Fallback for other systems
230** =======================================================
231*/
232
233#undef LIB_FAIL
234#define LIB_FAIL "absent"
235
236
237#define DLMSG "dynamic libraries not enabled; check your Lua installation"
238
239
240static void lsys_unloadlib (void *lib) {
241 (void)(lib); /* not used */
242}
243
244
245static void *lsys_load (lua_State *L, const char *path, int seeglb) {
246 (void)(path); (void)(seeglb); /* not used */
247 lua_pushliteral(L, DLMSG);
248 return NULL;
249}
250
251
252static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
253 (void)(lib); (void)(sym); /* not used */
254 lua_pushliteral(L, DLMSG);
255 return NULL;
256}
257
258/* }====================================================== */
259#endif /* } */
260
261
262/*
263** {==================================================================
264** Set Paths
265** ===================================================================
266*/
267
268/*
269** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
270** variables that Lua check to set its paths.
271*/
272#if !defined(LUA_PATH_VAR)
273#define LUA_PATH_VAR "LUA_PATH"
274#endif
275
276#if !defined(LUA_CPATH_VAR)
277#define LUA_CPATH_VAR "LUA_CPATH"
278#endif
279
280
281
282/*
283** return registry.LUA_NOENV as a boolean
284*/
285static int noenv (lua_State *L) {
286 int b;
287 lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
288 b = lua_toboolean(L, -1);
289 lua_pop(L, 1); /* remove value */
290 return b;
291}
292
293
294/*
295** Set a path
296*/
297static void setpath (lua_State *L, const char *fieldname,
298 const char *envname,
299 const char *dft) {
300 const char *dftmark;
301 const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX);
302 const char *path = getenv(nver); /* try versioned name */
303 if (path == NULL) /* no versioned environment variable? */
304 path = getenv(envname); /* try unversioned name */
305 if (path == NULL || noenv(L)) /* no environment variable? */
306 lua_pushstring(L, dft); /* use default */
307 else if ((dftmark = strstr(path, LUA_PATH_SEP LUA_PATH_SEP)) == NULL)
308 lua_pushstring(L, path); /* nothing to change */
309 else { /* path contains a ";;": insert default path in its place */
310 size_t len = strlen(path);
311 luaL_Buffer b;
312 luaL_buffinit(L, &b);
313 if (path < dftmark) { /* is there a prefix before ';;'? */
314 luaL_addlstring(&b, path, dftmark - path); /* add it */
315 luaL_addchar(&b, *LUA_PATH_SEP);
316 }
317 luaL_addstring(&b, dft); /* add default */
318 if (dftmark < path + len - 2) { /* is there a suffix after ';;'? */
319 luaL_addchar(&b, *LUA_PATH_SEP);
320 luaL_addlstring(&b, dftmark + 2, (path + len - 2) - dftmark);
321 }
322 luaL_pushresult(&b);
323 }
324 setprogdir(L);
325 lua_setfield(L, -3, fieldname); /* package[fieldname] = path value */
326 lua_pop(L, 1); /* pop versioned variable name ('nver') */
327}
328
329/* }================================================================== */
330
331
332/*
333** return registry.CLIBS[path]
334*/
335static void *checkclib (lua_State *L, const char *path) {
336 void *plib;
337 lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
338 lua_getfield(L, -1, path);
339 plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
340 lua_pop(L, 2); /* pop CLIBS table and 'plib' */
341 return plib;
342}
343
344
345/*
346** registry.CLIBS[path] = plib -- for queries
347** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
348*/
349static void addtoclib (lua_State *L, const char *path, void *plib) {
350 lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
351 lua_pushlightuserdata(L, plib);
352 lua_pushvalue(L, -1);
353 lua_setfield(L, -3, path); /* CLIBS[path] = plib */
354 lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
355 lua_pop(L, 1); /* pop CLIBS table */
356}
357
358
359/*
360** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
361** handles in list CLIBS
362*/
363static int gctm (lua_State *L) {
364 lua_Integer n = luaL_len(L, 1);
365 for (; n >= 1; n--) { /* for each handle, in reverse order */
366 lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
367 lsys_unloadlib(lua_touserdata(L, -1));
368 lua_pop(L, 1); /* pop handle */
369 }
370 return 0;
371}
372
373
374
375/* error codes for 'lookforfunc' */
376#define ERRLIB 1
377#define ERRFUNC 2
378
379/*
380** Look for a C function named 'sym' in a dynamically loaded library
381** 'path'.
382** First, check whether the library is already loaded; if not, try
383** to load it.
384** Then, if 'sym' is '*', return true (as library has been loaded).
385** Otherwise, look for symbol 'sym' in the library and push a
386** C function with that symbol.
387** Return 0 and 'true' or a function in the stack; in case of
388** errors, return an error code and an error message in the stack.
389*/
390static int lookforfunc (lua_State *L, const char *path, const char *sym) {
391 void *reg = checkclib(L, path); /* check loaded C libraries */
392 if (reg == NULL) { /* must load library? */
393 reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */
394 if (reg == NULL) return ERRLIB; /* unable to load library */
395 addtoclib(L, path, reg);
396 }
397 if (*sym == '*') { /* loading only library (no function)? */
398 lua_pushboolean(L, 1); /* return 'true' */
399 return 0; /* no errors */
400 }
401 else {
402 lua_CFunction f = lsys_sym(L, reg, sym);
403 if (f == NULL)
404 return ERRFUNC; /* unable to find function */
405 lua_pushcfunction(L, f); /* else create new function */
406 return 0; /* no errors */
407 }
408}
409
410
411static int ll_loadlib (lua_State *L) {
412 const char *path = luaL_checkstring(L, 1);
413 const char *init = luaL_checkstring(L, 2);
414 int stat = lookforfunc(L, path, init);
415 if (l_likely(stat == 0)) /* no errors? */
416 return 1; /* return the loaded function */
417 else { /* error; error message is on stack top */
418 luaL_pushfail(L);
419 lua_insert(L, -2);
420 lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
421 return 3; /* return fail, error message, and where */
422 }
423}
424
425
426
427/*
428** {======================================================
429** 'require' function
430** =======================================================
431*/
432
433
434static int readable (const char *filename) {
435 FILE *f = fopen(filename, "r"); /* try to open file */
436 if (f == NULL) return 0; /* open failed */
437 fclose(f);
438 return 1;
439}
440
441
442/*
443** Get the next name in '*path' = 'name1;name2;name3;...', changing
444** the ending ';' to '\0' to create a zero-terminated string. Return
445** NULL when list ends.
446*/
447static const char *getnextfilename (char **path, char *end) {
448 char *sep;
449 char *name = *path;
450 if (name == end)
451 return NULL; /* no more names */
452 else if (*name == '\0') { /* from previous iteration? */
453 *name = *LUA_PATH_SEP; /* restore separator */
454 name++; /* skip it */
455 }
456 sep = strchr(name, *LUA_PATH_SEP); /* find next separator */
457 if (sep == NULL) /* separator not found? */
458 sep = end; /* name goes until the end */
459 *sep = '\0'; /* finish file name */
460 *path = sep; /* will start next search from here */
461 return name;
462}
463
464
465/*
466** Given a path such as ";blabla.so;blublu.so", pushes the string
467**
468** no file 'blabla.so'
469** no file 'blublu.so'
470*/
471static void pusherrornotfound (lua_State *L, const char *path) {
472 luaL_Buffer b;
473 luaL_buffinit(L, &b);
474 luaL_addstring(&b, "no file '");
475 luaL_addgsub(&b, path, LUA_PATH_SEP, "'\n\tno file '");
476 luaL_addstring(&b, "'");
477 luaL_pushresult(&b);
478}
479
480
481static const char *searchpath (lua_State *L, const char *name,
482 const char *path,
483 const char *sep,
484 const char *dirsep) {
485 luaL_Buffer buff;
486 char *pathname; /* path with name inserted */
487 char *endpathname; /* its end */
488 const char *filename;
489 /* separator is non-empty and appears in 'name'? */
490 if (*sep != '\0' && strchr(name, *sep) != NULL)
491 name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
492 luaL_buffinit(L, &buff);
493 /* add path to the buffer, replacing marks ('?') with the file name */
494 luaL_addgsub(&buff, path, LUA_PATH_MARK, name);
495 luaL_addchar(&buff, '\0');
496 pathname = luaL_buffaddr(&buff); /* writable list of file names */
497 endpathname = pathname + luaL_bufflen(&buff) - 1;
498 while ((filename = getnextfilename(&pathname, endpathname)) != NULL) {
499 if (readable(filename)) /* does file exist and is readable? */
500 return lua_pushstring(L, filename); /* save and return name */
501 }
502 luaL_pushresult(&buff); /* push path to create error message */
503 pusherrornotfound(L, lua_tostring(L, -1)); /* create error message */
504 return NULL; /* not found */
505}
506
507
508static int ll_searchpath (lua_State *L) {
509 const char *f = searchpath(L, luaL_checkstring(L, 1),
510 luaL_checkstring(L, 2),
511 luaL_optstring(L, 3, "."),
512 luaL_optstring(L, 4, LUA_DIRSEP));
513 if (f != NULL) return 1;
514 else { /* error message is on top of the stack */
515 luaL_pushfail(L);
516 lua_insert(L, -2);
517 return 2; /* return fail + error message */
518 }
519}
520
521
522static const char *findfile (lua_State *L, const char *name,
523 const char *pname,
524 const char *dirsep) {
525 const char *path;
526 lua_getfield(L, lua_upvalueindex(1), pname);
527 path = lua_tostring(L, -1);
528 if (l_unlikely(path == NULL))
529 luaL_error(L, "'package.%s' must be a string", pname);
530 return searchpath(L, name, path, ".", dirsep);
531}
532
533
534static int checkload (lua_State *L, int stat, const char *filename) {
535 if (l_likely(stat)) { /* module loaded successfully? */
536 lua_pushstring(L, filename); /* will be 2nd argument to module */
537 return 2; /* return open function and file name */
538 }
539 else
540 return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s",
541 lua_tostring(L, 1), filename, lua_tostring(L, -1));
542}
543
544
545static int searcher_Lua (lua_State *L) {
546 const char *filename;
547 const char *name = luaL_checkstring(L, 1);
548 filename = findfile(L, name, "path", LUA_LSUBSEP);
549 if (filename == NULL) return 1; /* module not found in this path */
550 return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
551}
552
553
554/*
555** Try to find a load function for module 'modname' at file 'filename'.
556** First, change '.' to '_' in 'modname'; then, if 'modname' has
557** the form X-Y (that is, it has an "ignore mark"), build a function
558** name "luaopen_X" and look for it. (For compatibility, if that
559** fails, it also tries "luaopen_Y".) If there is no ignore mark,
560** look for a function named "luaopen_modname".
561*/
562static int loadfunc (lua_State *L, const char *filename, const char *modname) {
563 const char *openfunc;
564 const char *mark;
565 modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
566 mark = strchr(modname, *LUA_IGMARK);
567 if (mark) {
568 int stat;
569 openfunc = lua_pushlstring(L, modname, mark - modname);
570 openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
571 stat = lookforfunc(L, filename, openfunc);
572 if (stat != ERRFUNC) return stat;
573 modname = mark + 1; /* else go ahead and try old-style name */
574 }
575 openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
576 return lookforfunc(L, filename, openfunc);
577}
578
579
580static int searcher_C (lua_State *L) {
581 const char *name = luaL_checkstring(L, 1);
582 const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
583 if (filename == NULL) return 1; /* module not found in this path */
584 return checkload(L, (loadfunc(L, filename, name) == 0), filename);
585}
586
587
588static int searcher_Croot (lua_State *L) {
589 const char *filename;
590 const char *name = luaL_checkstring(L, 1);
591 const char *p = strchr(name, '.');
592 int stat;
593 if (p == NULL) return 0; /* is root */
594 lua_pushlstring(L, name, p - name);
595 filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
596 if (filename == NULL) return 1; /* root not found */
597 if ((stat = loadfunc(L, filename, name)) != 0) {
598 if (stat != ERRFUNC)
599 return checkload(L, 0, filename); /* real error */
600 else { /* open function not found */
601 lua_pushfstring(L, "no module '%s' in file '%s'", name, filename);
602 return 1;
603 }
604 }
605 lua_pushstring(L, filename); /* will be 2nd argument to module */
606 return 2;
607}
608
609
610static int searcher_preload (lua_State *L) {
611 const char *name = luaL_checkstring(L, 1);
612 lua_getfield(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
613 if (lua_getfield(L, -1, name) == LUA_TNIL) { /* not found? */
614 lua_pushfstring(L, "no field package.preload['%s']", name);
615 return 1;
616 }
617 else {
618 lua_pushliteral(L, ":preload:");
619 return 2;
620 }
621}
622
623
624static void findloader (lua_State *L, const char *name) {
625 int i;
626 luaL_Buffer msg; /* to build error message */
627 /* push 'package.searchers' to index 3 in the stack */
628 if (l_unlikely(lua_getfield(L, lua_upvalueindex(1), "searchers")
629 != LUA_TTABLE))
630 luaL_error(L, "'package.searchers' must be a table");
631 luaL_buffinit(L, &msg);
632 /* iterate over available searchers to find a loader */
633 for (i = 1; ; i++) {
634 luaL_addstring(&msg, "\n\t"); /* error-message prefix */
635 if (l_unlikely(lua_rawgeti(L, 3, i) == LUA_TNIL)) { /* no more searchers? */
636 lua_pop(L, 1); /* remove nil */
637 luaL_buffsub(&msg, 2); /* remove prefix */
638 luaL_pushresult(&msg); /* create error message */
639 luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
640 }
641 lua_pushstring(L, name);
642 lua_call(L, 1, 2); /* call it */
643 if (lua_isfunction(L, -2)) /* did it find a loader? */
644 return; /* module loader found */
645 else if (lua_isstring(L, -2)) { /* searcher returned error message? */
646 lua_pop(L, 1); /* remove extra return */
647 luaL_addvalue(&msg); /* concatenate error message */
648 }
649 else { /* no error message */
650 lua_pop(L, 2); /* remove both returns */
651 luaL_buffsub(&msg, 2); /* remove prefix */
652 }
653 }
654}
655
656
657static int ll_require (lua_State *L) {
658 const char *name = luaL_checkstring(L, 1);
659 lua_settop(L, 1); /* LOADED table will be at index 2 */
660 lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
661 lua_getfield(L, 2, name); /* LOADED[name] */
662 if (lua_toboolean(L, -1)) /* is it there? */
663 return 1; /* package is already loaded */
664 /* else must load package */
665 lua_pop(L, 1); /* remove 'getfield' result */
666 findloader(L, name);
667 lua_rotate(L, -2, 1); /* function <-> loader data */
668 lua_pushvalue(L, 1); /* name is 1st argument to module loader */
669 lua_pushvalue(L, -3); /* loader data is 2nd argument */
670 /* stack: ...; loader data; loader function; mod. name; loader data */
671 lua_call(L, 2, 1); /* run loader to load module */
672 /* stack: ...; loader data; result from loader */
673 if (!lua_isnil(L, -1)) /* non-nil return? */
674 lua_setfield(L, 2, name); /* LOADED[name] = returned value */
675 else
676 lua_pop(L, 1); /* pop nil */
677 if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */
678 lua_pushboolean(L, 1); /* use true as result */
679 lua_copy(L, -1, -2); /* replace loader result */
680 lua_setfield(L, 2, name); /* LOADED[name] = true */
681 }
682 lua_rotate(L, -2, 1); /* loader data <-> module result */
683 return 2; /* return module result and loader data */
684}
685
686/* }====================================================== */
687
688
689
690
691static const luaL_Reg pk_funcs[] = {
692 {"loadlib", ll_loadlib},
693 {"searchpath", ll_searchpath},
694 /* placeholders */
695 {"preload", NULL},
696 {"cpath", NULL},
697 {"path", NULL},
698 {"searchers", NULL},
699 {"loaded", NULL},
700 {NULL, NULL}
701};
702
703
704static const luaL_Reg ll_funcs[] = {
705 {"require", ll_require},
706 {NULL, NULL}
707};
708
709
710static void createsearcherstable (lua_State *L) {
711 static const lua_CFunction searchers[] =
712 {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
713 int i;
714 /* create 'searchers' table */
715 lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
716 /* fill it with predefined searchers */
717 for (i=0; searchers[i] != NULL; i++) {
718 lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
719 lua_pushcclosure(L, searchers[i], 1);
720 lua_rawseti(L, -2, i+1);
721 }
722 lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
723}
724
725
726/*
727** create table CLIBS to keep track of loaded C libraries,
728** setting a finalizer to close all libraries when closing state.
729*/
730static void createclibstable (lua_State *L) {
731 luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS); /* create CLIBS table */
732 lua_createtable(L, 0, 1); /* create metatable for CLIBS */
733 lua_pushcfunction(L, gctm);
734 lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */
735 lua_setmetatable(L, -2);
736}
737
738
739LUAMOD_API int luaopen_package (lua_State *L) {
740 createclibstable(L);
741 luaL_newlib(L, pk_funcs); /* create 'package' table */
742 createsearcherstable(L);
743 /* set paths */
744 setpath(L, "path", LUA_PATH_VAR, LUA_PATH_DEFAULT);
745 setpath(L, "cpath", LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
746 /* store config information */
747 lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
748 LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
749 lua_setfield(L, -2, "config");
750 /* set field 'loaded' */
751 luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
752 lua_setfield(L, -2, "loaded");
753 /* set field 'preload' */
754 luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
755 lua_setfield(L, -2, "preload");
756 lua_pushglobaltable(L);
757 lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
758 luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
759 lua_pop(L, 1); /* pop global table */
760 return 1; /* return 'package' table */
761}
762
763