ba8b5c17 |
1 | /* |
2 | ** $Id: liolib.c,v 2.111 2013/03/21 13:57:27 roberto Exp $ |
3 | ** Standard I/O (and system) library |
4 | ** See Copyright Notice in lua.h |
5 | */ |
6 | |
7 | |
8 | /* |
9 | ** POSIX idiosyncrasy! |
10 | ** This definition must come before the inclusion of 'stdio.h'; it |
11 | ** should not affect non-POSIX systems |
12 | */ |
13 | #if !defined(_FILE_OFFSET_BITS) |
14 | #define _FILE_OFFSET_BITS 64 |
15 | #endif |
16 | |
17 | |
18 | #include <errno.h> |
19 | #include <stdio.h> |
20 | #include <stdlib.h> |
21 | #include <string.h> |
22 | |
23 | #define liolib_c |
24 | #define LUA_LIB |
25 | |
26 | #include "lua.h" |
27 | |
28 | #include "lauxlib.h" |
29 | #include "lualib.h" |
30 | |
31 | |
32 | #if !defined(lua_checkmode) |
33 | |
34 | /* |
35 | ** Check whether 'mode' matches '[rwa]%+?b?'. |
36 | ** Change this macro to accept other modes for 'fopen' besides |
37 | ** the standard ones. |
38 | */ |
39 | #define lua_checkmode(mode) \ |
40 | (*mode != '\0' && strchr("rwa", *(mode++)) != NULL && \ |
41 | (*mode != '+' || ++mode) && /* skip if char is '+' */ \ |
42 | (*mode != 'b' || ++mode) && /* skip if char is 'b' */ \ |
43 | (*mode == '\0')) |
44 | |
45 | #endif |
46 | |
47 | /* |
48 | ** {====================================================== |
49 | ** lua_popen spawns a new process connected to the current |
50 | ** one through the file streams. |
51 | ** ======================================================= |
52 | */ |
53 | |
54 | #if !defined(lua_popen) /* { */ |
55 | |
56 | #if defined(LUA_USE_POPEN) /* { */ |
57 | |
58 | #define lua_popen(L,c,m) ((void)L, fflush(NULL), popen(c,m)) |
59 | #define lua_pclose(L,file) ((void)L, pclose(file)) |
60 | |
61 | #elif defined(LUA_WIN) /* }{ */ |
62 | |
63 | #define lua_popen(L,c,m) ((void)L, _popen(c,m)) |
64 | #define lua_pclose(L,file) ((void)L, _pclose(file)) |
65 | |
66 | |
67 | #else /* }{ */ |
68 | |
69 | #define lua_popen(L,c,m) ((void)((void)c, m), \ |
70 | luaL_error(L, LUA_QL("popen") " not supported"), (FILE*)0) |
71 | #define lua_pclose(L,file) ((void)((void)L, file), -1) |
72 | |
73 | |
74 | #endif /* } */ |
75 | |
76 | #endif /* } */ |
77 | |
78 | /* }====================================================== */ |
79 | |
80 | |
81 | /* |
82 | ** {====================================================== |
83 | ** lua_fseek/lua_ftell: configuration for longer offsets |
84 | ** ======================================================= |
85 | */ |
86 | |
87 | #if !defined(lua_fseek) /* { */ |
88 | |
89 | #if defined(LUA_USE_POSIX) |
90 | |
91 | #define l_fseek(f,o,w) fseeko(f,o,w) |
92 | #define l_ftell(f) ftello(f) |
93 | #define l_seeknum off_t |
94 | |
95 | #elif defined(LUA_WIN) && !defined(_CRTIMP_TYPEINFO) \ |
96 | && defined(_MSC_VER) && (_MSC_VER >= 1400) |
97 | /* Windows (but not DDK) and Visual C++ 2005 or higher */ |
98 | |
99 | #define l_fseek(f,o,w) _fseeki64(f,o,w) |
100 | #define l_ftell(f) _ftelli64(f) |
101 | #define l_seeknum __int64 |
102 | |
103 | #else |
104 | |
105 | #define l_fseek(f,o,w) fseek(f,o,w) |
106 | #define l_ftell(f) ftell(f) |
107 | #define l_seeknum long |
108 | |
109 | #endif |
110 | |
111 | #endif /* } */ |
112 | |
113 | /* }====================================================== */ |
114 | |
115 | |
116 | #define IO_PREFIX "_IO_" |
117 | #define IO_INPUT (IO_PREFIX "input") |
118 | #define IO_OUTPUT (IO_PREFIX "output") |
119 | |
120 | |
121 | typedef luaL_Stream LStream; |
122 | |
123 | |
124 | #define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE)) |
125 | |
126 | #define isclosed(p) ((p)->closef == NULL) |
127 | |
128 | |
129 | static int io_type (lua_State *L) { |
130 | LStream *p; |
131 | luaL_checkany(L, 1); |
132 | p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE); |
133 | if (p == NULL) |
134 | lua_pushnil(L); /* not a file */ |
135 | else if (isclosed(p)) |
136 | lua_pushliteral(L, "closed file"); |
137 | else |
138 | lua_pushliteral(L, "file"); |
139 | return 1; |
140 | } |
141 | |
142 | |
143 | static int f_tostring (lua_State *L) { |
144 | LStream *p = tolstream(L); |
145 | if (isclosed(p)) |
146 | lua_pushliteral(L, "file (closed)"); |
147 | else |
148 | lua_pushfstring(L, "file (%p)", p->f); |
149 | return 1; |
150 | } |
151 | |
152 | |
153 | static FILE *tofile (lua_State *L) { |
154 | LStream *p = tolstream(L); |
155 | if (isclosed(p)) |
156 | luaL_error(L, "attempt to use a closed file"); |
157 | lua_assert(p->f); |
158 | return p->f; |
159 | } |
160 | |
161 | |
162 | /* |
163 | ** When creating file handles, always creates a `closed' file handle |
164 | ** before opening the actual file; so, if there is a memory error, the |
165 | ** file is not left opened. |
166 | */ |
167 | static LStream *newprefile (lua_State *L) { |
168 | LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream)); |
169 | p->closef = NULL; /* mark file handle as 'closed' */ |
170 | luaL_setmetatable(L, LUA_FILEHANDLE); |
171 | return p; |
172 | } |
173 | |
174 | |
175 | static int aux_close (lua_State *L) { |
176 | LStream *p = tolstream(L); |
177 | lua_CFunction cf = p->closef; |
178 | p->closef = NULL; /* mark stream as closed */ |
179 | return (*cf)(L); /* close it */ |
180 | } |
181 | |
182 | |
183 | static int io_close (lua_State *L) { |
184 | if (lua_isnone(L, 1)) /* no argument? */ |
185 | lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use standard output */ |
186 | tofile(L); /* make sure argument is an open stream */ |
187 | return aux_close(L); |
188 | } |
189 | |
190 | |
191 | static int f_gc (lua_State *L) { |
192 | LStream *p = tolstream(L); |
193 | if (!isclosed(p) && p->f != NULL) |
194 | aux_close(L); /* ignore closed and incompletely open files */ |
195 | return 0; |
196 | } |
197 | |
198 | |
199 | /* |
200 | ** function to close regular files |
201 | */ |
202 | static int io_fclose (lua_State *L) { |
203 | LStream *p = tolstream(L); |
204 | int res = fclose(p->f); |
205 | return luaL_fileresult(L, (res == 0), NULL); |
206 | } |
207 | |
208 | |
209 | static LStream *newfile (lua_State *L) { |
210 | LStream *p = newprefile(L); |
211 | p->f = NULL; |
212 | p->closef = &io_fclose; |
213 | return p; |
214 | } |
215 | |
216 | |
217 | static void opencheck (lua_State *L, const char *fname, const char *mode) { |
218 | LStream *p = newfile(L); |
219 | p->f = fopen(fname, mode); |
220 | if (p->f == NULL) |
221 | luaL_error(L, "cannot open file " LUA_QS " (%s)", fname, strerror(errno)); |
222 | } |
223 | |
224 | |
225 | static int io_open (lua_State *L) { |
226 | const char *filename = luaL_checkstring(L, 1); |
227 | const char *mode = luaL_optstring(L, 2, "r"); |
228 | LStream *p = newfile(L); |
229 | const char *md = mode; /* to traverse/check mode */ |
230 | luaL_argcheck(L, lua_checkmode(md), 2, "invalid mode"); |
231 | p->f = fopen(filename, mode); |
232 | return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; |
233 | } |
234 | |
235 | |
236 | /* |
237 | ** function to close 'popen' files |
238 | */ |
239 | static int io_pclose (lua_State *L) { |
240 | LStream *p = tolstream(L); |
241 | return luaL_execresult(L, lua_pclose(L, p->f)); |
242 | } |
243 | |
244 | |
245 | static int io_popen (lua_State *L) { |
246 | const char *filename = luaL_checkstring(L, 1); |
247 | const char *mode = luaL_optstring(L, 2, "r"); |
248 | LStream *p = newprefile(L); |
249 | p->f = lua_popen(L, filename, mode); |
250 | p->closef = &io_pclose; |
251 | return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; |
252 | } |
253 | |
254 | |
255 | static int io_tmpfile (lua_State *L) { |
256 | LStream *p = newfile(L); |
257 | p->f = tmpfile(); |
258 | return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; |
259 | } |
260 | |
261 | |
262 | static FILE *getiofile (lua_State *L, const char *findex) { |
263 | LStream *p; |
264 | lua_getfield(L, LUA_REGISTRYINDEX, findex); |
265 | p = (LStream *)lua_touserdata(L, -1); |
266 | if (isclosed(p)) |
267 | luaL_error(L, "standard %s file is closed", findex + strlen(IO_PREFIX)); |
268 | return p->f; |
269 | } |
270 | |
271 | |
272 | static int g_iofile (lua_State *L, const char *f, const char *mode) { |
273 | if (!lua_isnoneornil(L, 1)) { |
274 | const char *filename = lua_tostring(L, 1); |
275 | if (filename) |
276 | opencheck(L, filename, mode); |
277 | else { |
278 | tofile(L); /* check that it's a valid file handle */ |
279 | lua_pushvalue(L, 1); |
280 | } |
281 | lua_setfield(L, LUA_REGISTRYINDEX, f); |
282 | } |
283 | /* return current value */ |
284 | lua_getfield(L, LUA_REGISTRYINDEX, f); |
285 | return 1; |
286 | } |
287 | |
288 | |
289 | static int io_input (lua_State *L) { |
290 | return g_iofile(L, IO_INPUT, "r"); |
291 | } |
292 | |
293 | |
294 | static int io_output (lua_State *L) { |
295 | return g_iofile(L, IO_OUTPUT, "w"); |
296 | } |
297 | |
298 | |
299 | static int io_readline (lua_State *L); |
300 | |
301 | |
302 | static void aux_lines (lua_State *L, int toclose) { |
303 | int i; |
304 | int n = lua_gettop(L) - 1; /* number of arguments to read */ |
305 | /* ensure that arguments will fit here and into 'io_readline' stack */ |
306 | luaL_argcheck(L, n <= LUA_MINSTACK - 3, LUA_MINSTACK - 3, "too many options"); |
307 | lua_pushvalue(L, 1); /* file handle */ |
308 | lua_pushinteger(L, n); /* number of arguments to read */ |
309 | lua_pushboolean(L, toclose); /* close/not close file when finished */ |
310 | for (i = 1; i <= n; i++) lua_pushvalue(L, i + 1); /* copy arguments */ |
311 | lua_pushcclosure(L, io_readline, 3 + n); |
312 | } |
313 | |
314 | |
315 | static int f_lines (lua_State *L) { |
316 | tofile(L); /* check that it's a valid file handle */ |
317 | aux_lines(L, 0); |
318 | return 1; |
319 | } |
320 | |
321 | |
322 | static int io_lines (lua_State *L) { |
323 | int toclose; |
324 | if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */ |
325 | if (lua_isnil(L, 1)) { /* no file name? */ |
326 | lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */ |
327 | lua_replace(L, 1); /* put it at index 1 */ |
328 | tofile(L); /* check that it's a valid file handle */ |
329 | toclose = 0; /* do not close it after iteration */ |
330 | } |
331 | else { /* open a new file */ |
332 | const char *filename = luaL_checkstring(L, 1); |
333 | opencheck(L, filename, "r"); |
334 | lua_replace(L, 1); /* put file at index 1 */ |
335 | toclose = 1; /* close it after iteration */ |
336 | } |
337 | aux_lines(L, toclose); |
338 | return 1; |
339 | } |
340 | |
341 | |
342 | /* |
343 | ** {====================================================== |
344 | ** READ |
345 | ** ======================================================= |
346 | */ |
347 | |
348 | |
349 | static int read_number (lua_State *L, FILE *f) { |
350 | lua_Number d; |
351 | if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) { |
352 | lua_pushnumber(L, d); |
353 | return 1; |
354 | } |
355 | else { |
356 | lua_pushnil(L); /* "result" to be removed */ |
357 | return 0; /* read fails */ |
358 | } |
359 | } |
360 | |
361 | |
362 | static int test_eof (lua_State *L, FILE *f) { |
363 | int c = getc(f); |
364 | ungetc(c, f); |
365 | lua_pushlstring(L, NULL, 0); |
366 | return (c != EOF); |
367 | } |
368 | |
369 | |
370 | static int read_line (lua_State *L, FILE *f, int chop) { |
371 | luaL_Buffer b; |
372 | luaL_buffinit(L, &b); |
373 | for (;;) { |
374 | size_t l; |
375 | char *p = luaL_prepbuffer(&b); |
376 | if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */ |
377 | luaL_pushresult(&b); /* close buffer */ |
378 | return (lua_rawlen(L, -1) > 0); /* check whether read something */ |
379 | } |
380 | l = strlen(p); |
381 | if (l == 0 || p[l-1] != '\n') |
382 | luaL_addsize(&b, l); |
383 | else { |
384 | luaL_addsize(&b, l - chop); /* chop 'eol' if needed */ |
385 | luaL_pushresult(&b); /* close buffer */ |
386 | return 1; /* read at least an `eol' */ |
387 | } |
388 | } |
389 | } |
390 | |
391 | |
392 | #define MAX_SIZE_T (~(size_t)0) |
393 | |
394 | static void read_all (lua_State *L, FILE *f) { |
395 | size_t rlen = LUAL_BUFFERSIZE; /* how much to read in each cycle */ |
396 | luaL_Buffer b; |
397 | luaL_buffinit(L, &b); |
398 | for (;;) { |
399 | char *p = luaL_prepbuffsize(&b, rlen); |
400 | size_t nr = fread(p, sizeof(char), rlen, f); |
401 | luaL_addsize(&b, nr); |
402 | if (nr < rlen) break; /* eof? */ |
403 | else if (rlen <= (MAX_SIZE_T / 4)) /* avoid buffers too large */ |
404 | rlen *= 2; /* double buffer size at each iteration */ |
405 | } |
406 | luaL_pushresult(&b); /* close buffer */ |
407 | } |
408 | |
409 | |
410 | static int read_chars (lua_State *L, FILE *f, size_t n) { |
411 | size_t nr; /* number of chars actually read */ |
412 | char *p; |
413 | luaL_Buffer b; |
414 | luaL_buffinit(L, &b); |
415 | p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */ |
416 | nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */ |
417 | luaL_addsize(&b, nr); |
418 | luaL_pushresult(&b); /* close buffer */ |
419 | return (nr > 0); /* true iff read something */ |
420 | } |
421 | |
422 | |
423 | static int g_read (lua_State *L, FILE *f, int first) { |
424 | int nargs = lua_gettop(L) - 1; |
425 | int success; |
426 | int n; |
427 | clearerr(f); |
428 | if (nargs == 0) { /* no arguments? */ |
429 | success = read_line(L, f, 1); |
430 | n = first+1; /* to return 1 result */ |
431 | } |
432 | else { /* ensure stack space for all results and for auxlib's buffer */ |
433 | luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); |
434 | success = 1; |
435 | for (n = first; nargs-- && success; n++) { |
436 | if (lua_type(L, n) == LUA_TNUMBER) { |
437 | size_t l = (size_t)lua_tointeger(L, n); |
438 | success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); |
439 | } |
440 | else { |
441 | const char *p = lua_tostring(L, n); |
442 | luaL_argcheck(L, p && p[0] == '*', n, "invalid option"); |
443 | switch (p[1]) { |
444 | case 'n': /* number */ |
445 | success = read_number(L, f); |
446 | break; |
447 | case 'l': /* line */ |
448 | success = read_line(L, f, 1); |
449 | break; |
450 | case 'L': /* line with end-of-line */ |
451 | success = read_line(L, f, 0); |
452 | break; |
453 | case 'a': /* file */ |
454 | read_all(L, f); /* read entire file */ |
455 | success = 1; /* always success */ |
456 | break; |
457 | default: |
458 | return luaL_argerror(L, n, "invalid format"); |
459 | } |
460 | } |
461 | } |
462 | } |
463 | if (ferror(f)) |
464 | return luaL_fileresult(L, 0, NULL); |
465 | if (!success) { |
466 | lua_pop(L, 1); /* remove last result */ |
467 | lua_pushnil(L); /* push nil instead */ |
468 | } |
469 | return n - first; |
470 | } |
471 | |
472 | |
473 | static int io_read (lua_State *L) { |
474 | return g_read(L, getiofile(L, IO_INPUT), 1); |
475 | } |
476 | |
477 | |
478 | static int f_read (lua_State *L) { |
479 | return g_read(L, tofile(L), 2); |
480 | } |
481 | |
482 | |
483 | static int io_readline (lua_State *L) { |
484 | LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1)); |
485 | int i; |
486 | int n = (int)lua_tointeger(L, lua_upvalueindex(2)); |
487 | if (isclosed(p)) /* file is already closed? */ |
488 | return luaL_error(L, "file is already closed"); |
489 | lua_settop(L , 1); |
490 | for (i = 1; i <= n; i++) /* push arguments to 'g_read' */ |
491 | lua_pushvalue(L, lua_upvalueindex(3 + i)); |
492 | n = g_read(L, p->f, 2); /* 'n' is number of results */ |
493 | lua_assert(n > 0); /* should return at least a nil */ |
494 | if (!lua_isnil(L, -n)) /* read at least one value? */ |
495 | return n; /* return them */ |
496 | else { /* first result is nil: EOF or error */ |
497 | if (n > 1) { /* is there error information? */ |
498 | /* 2nd result is error message */ |
499 | return luaL_error(L, "%s", lua_tostring(L, -n + 1)); |
500 | } |
501 | if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */ |
502 | lua_settop(L, 0); |
503 | lua_pushvalue(L, lua_upvalueindex(1)); |
504 | aux_close(L); /* close it */ |
505 | } |
506 | return 0; |
507 | } |
508 | } |
509 | |
510 | /* }====================================================== */ |
511 | |
512 | |
513 | static int g_write (lua_State *L, FILE *f, int arg) { |
514 | int nargs = lua_gettop(L) - arg; |
515 | int status = 1; |
516 | for (; nargs--; arg++) { |
517 | if (lua_type(L, arg) == LUA_TNUMBER) { |
518 | /* optimization: could be done exactly as for strings */ |
519 | status = status && |
520 | fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0; |
521 | } |
522 | else { |
523 | size_t l; |
524 | const char *s = luaL_checklstring(L, arg, &l); |
525 | status = status && (fwrite(s, sizeof(char), l, f) == l); |
526 | } |
527 | } |
528 | if (status) return 1; /* file handle already on stack top */ |
529 | else return luaL_fileresult(L, status, NULL); |
530 | } |
531 | |
532 | |
533 | static int io_write (lua_State *L) { |
534 | return g_write(L, getiofile(L, IO_OUTPUT), 1); |
535 | } |
536 | |
537 | |
538 | static int f_write (lua_State *L) { |
539 | FILE *f = tofile(L); |
540 | lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */ |
541 | return g_write(L, f, 2); |
542 | } |
543 | |
544 | |
545 | static int f_seek (lua_State *L) { |
546 | static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; |
547 | static const char *const modenames[] = {"set", "cur", "end", NULL}; |
548 | FILE *f = tofile(L); |
549 | int op = luaL_checkoption(L, 2, "cur", modenames); |
550 | lua_Number p3 = luaL_optnumber(L, 3, 0); |
551 | l_seeknum offset = (l_seeknum)p3; |
552 | luaL_argcheck(L, (lua_Number)offset == p3, 3, |
553 | "not an integer in proper range"); |
554 | op = l_fseek(f, offset, mode[op]); |
555 | if (op) |
556 | return luaL_fileresult(L, 0, NULL); /* error */ |
557 | else { |
558 | lua_pushnumber(L, (lua_Number)l_ftell(f)); |
559 | return 1; |
560 | } |
561 | } |
562 | |
563 | |
564 | static int f_setvbuf (lua_State *L) { |
565 | static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; |
566 | static const char *const modenames[] = {"no", "full", "line", NULL}; |
567 | FILE *f = tofile(L); |
568 | int op = luaL_checkoption(L, 2, NULL, modenames); |
569 | lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); |
570 | int res = setvbuf(f, NULL, mode[op], sz); |
571 | return luaL_fileresult(L, res == 0, NULL); |
572 | } |
573 | |
574 | |
575 | |
576 | static int io_flush (lua_State *L) { |
577 | return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); |
578 | } |
579 | |
580 | |
581 | static int f_flush (lua_State *L) { |
582 | return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL); |
583 | } |
584 | |
585 | |
586 | /* |
587 | ** functions for 'io' library |
588 | */ |
589 | static const luaL_Reg iolib[] = { |
590 | {"close", io_close}, |
591 | {"flush", io_flush}, |
592 | {"input", io_input}, |
593 | {"lines", io_lines}, |
594 | {"open", io_open}, |
595 | {"output", io_output}, |
596 | {"popen", io_popen}, |
597 | {"read", io_read}, |
598 | {"tmpfile", io_tmpfile}, |
599 | {"type", io_type}, |
600 | {"write", io_write}, |
601 | {NULL, NULL} |
602 | }; |
603 | |
604 | |
605 | /* |
606 | ** methods for file handles |
607 | */ |
608 | static const luaL_Reg flib[] = { |
609 | {"close", io_close}, |
610 | {"flush", f_flush}, |
611 | {"lines", f_lines}, |
612 | {"read", f_read}, |
613 | {"seek", f_seek}, |
614 | {"setvbuf", f_setvbuf}, |
615 | {"write", f_write}, |
616 | {"__gc", f_gc}, |
617 | {"__tostring", f_tostring}, |
618 | {NULL, NULL} |
619 | }; |
620 | |
621 | |
622 | static void createmeta (lua_State *L) { |
623 | luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */ |
624 | lua_pushvalue(L, -1); /* push metatable */ |
625 | lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */ |
626 | luaL_setfuncs(L, flib, 0); /* add file methods to new metatable */ |
627 | lua_pop(L, 1); /* pop new metatable */ |
628 | } |
629 | |
630 | |
631 | /* |
632 | ** function to (not) close the standard files stdin, stdout, and stderr |
633 | */ |
634 | static int io_noclose (lua_State *L) { |
635 | LStream *p = tolstream(L); |
636 | p->closef = &io_noclose; /* keep file opened */ |
637 | lua_pushnil(L); |
638 | lua_pushliteral(L, "cannot close standard file"); |
639 | return 2; |
640 | } |
641 | |
642 | |
643 | static void createstdfile (lua_State *L, FILE *f, const char *k, |
644 | const char *fname) { |
645 | LStream *p = newprefile(L); |
646 | p->f = f; |
647 | p->closef = &io_noclose; |
648 | if (k != NULL) { |
649 | lua_pushvalue(L, -1); |
650 | lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */ |
651 | } |
652 | lua_setfield(L, -2, fname); /* add file to module */ |
653 | } |
654 | |
655 | |
656 | LUAMOD_API int luaopen_io (lua_State *L) { |
657 | luaL_newlib(L, iolib); /* new module */ |
658 | createmeta(L); |
659 | /* create (and set) default files */ |
660 | createstdfile(L, stdin, IO_INPUT, "stdin"); |
661 | createstdfile(L, stdout, IO_OUTPUT, "stdout"); |
662 | createstdfile(L, stderr, NULL, "stderr"); |
663 | return 1; |
664 | } |
665 | |