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
io_type(lua_State * L)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
f_tostring(lua_State * L)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
tofile(lua_State * L)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 */
newprefile(lua_State * L)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
aux_close(lua_State * L)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
io_close(lua_State * L)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
f_gc(lua_State * L)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 */
io_fclose(lua_State * L)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
newfile(lua_State * L)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
opencheck(lua_State * L,const char * fname,const char * mode)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
io_open(lua_State * L)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 */
io_pclose(lua_State * L)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
io_popen(lua_State * L)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
io_tmpfile(lua_State * L)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
getiofile(lua_State * L,const char * findex)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
g_iofile(lua_State * L,const char * f,const char * mode)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
io_input(lua_State * L)289 static int io_input (lua_State *L) {
290 return g_iofile(L, IO_INPUT, "r");
291 }
292
293
io_output(lua_State * L)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
aux_lines(lua_State * L,int toclose)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
f_lines(lua_State * L)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
io_lines(lua_State * L)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
read_number(lua_State * L,FILE * f)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
test_eof(lua_State * L,FILE * f)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
read_line(lua_State * L,FILE * f,int chop)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
read_all(lua_State * L,FILE * f)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
read_chars(lua_State * L,FILE * f,size_t n)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
g_read(lua_State * L,FILE * f,int first)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
io_read(lua_State * L)473 static int io_read (lua_State *L) {
474 return g_read(L, getiofile(L, IO_INPUT), 1);
475 }
476
477
f_read(lua_State * L)478 static int f_read (lua_State *L) {
479 return g_read(L, tofile(L), 2);
480 }
481
482
io_readline(lua_State * L)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
g_write(lua_State * L,FILE * f,int arg)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
io_write(lua_State * L)533 static int io_write (lua_State *L) {
534 return g_write(L, getiofile(L, IO_OUTPUT), 1);
535 }
536
537
f_write(lua_State * L)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
f_seek(lua_State * L)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
f_setvbuf(lua_State * L)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
io_flush(lua_State * L)576 static int io_flush (lua_State *L) {
577 return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
578 }
579
580
f_flush(lua_State * L)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
createmeta(lua_State * L)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 */
io_noclose(lua_State * L)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
createstdfile(lua_State * L,FILE * f,const char * k,const char * fname)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
luaopen_io(lua_State * L)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
666