Mercurial > mm7
comparison lib/lua/lua-5.2.2/liolib.c @ 1866:41cc4dd3c122
Lua 5.2.2 added.
author | Nomad |
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date | Wed, 16 Oct 2013 13:34:26 +0200 |
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1848:3b39b70e8e93 | 1866:41cc4dd3c122 |
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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 |