/lua/liolib.c
C | 666 lines | 470 code | 137 blank | 59 comment | 91 complexity | ce131ca289d111022f816486a34671f2 MD5 | raw file
Possible License(s): GPL-3.0, GPL-2.0
1/*
2** $Id: liolib.c,v 2.112.1.1 2013/04/12 18:48:47 roberto Exp $
3** Standard I/O (and system) library
4** See Copyright Notice in lua.h
5*/
6
7
8/*
9** This definition must come before the inclusion of 'stdio.h'; it
10** should not affect non-POSIX systems
11*/
12#if !defined(_FILE_OFFSET_BITS)
13#define _LARGEFILE_SOURCE 1
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: configuration for longer offsets
84** =======================================================
85*/
86
87#if !defined(lua_fseek) && !defined(LUA_ANSI) /* { */
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#endif /* } */
104
105#endif /* } */
106
107
108#if !defined(l_fseek) /* default definitions */
109#define l_fseek(f,o,w) fseek(f,o,w)
110#define l_ftell(f) ftell(f)
111#define l_seeknum long
112#endif
113
114/* }====================================================== */
115
116
117#define IO_PREFIX "_IO_"
118#define IO_INPUT (IO_PREFIX "input")
119#define IO_OUTPUT (IO_PREFIX "output")
120
121
122typedef luaL_Stream LStream;
123
124
125#define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE))
126
127#define isclosed(p) ((p)->closef == NULL)
128
129
130static int io_type (lua_State *L) {
131 LStream *p;
132 luaL_checkany(L, 1);
133 p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);
134 if (p == NULL)
135 lua_pushnil(L); /* not a file */
136 else if (isclosed(p))
137 lua_pushliteral(L, "closed file");
138 else
139 lua_pushliteral(L, "file");
140 return 1;
141}
142
143
144static int f_tostring (lua_State *L) {
145 LStream *p = tolstream(L);
146 if (isclosed(p))
147 lua_pushliteral(L, "file (closed)");
148 else
149 lua_pushfstring(L, "file (%p)", p->f);
150 return 1;
151}
152
153
154static FILE *tofile (lua_State *L) {
155 LStream *p = tolstream(L);
156 if (isclosed(p))
157 luaL_error(L, "attempt to use a closed file");
158 lua_assert(p->f);
159 return p->f;
160}
161
162
163/*
164** When creating file handles, always creates a `closed' file handle
165** before opening the actual file; so, if there is a memory error, the
166** file is not left opened.
167*/
168static LStream *newprefile (lua_State *L) {
169 LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));
170 p->closef = NULL; /* mark file handle as 'closed' */
171 luaL_setmetatable(L, LUA_FILEHANDLE);
172 return p;
173}
174
175
176static int aux_close (lua_State *L) {
177 LStream *p = tolstream(L);
178 lua_CFunction cf = p->closef;
179 p->closef = NULL; /* mark stream as closed */
180 return (*cf)(L); /* close it */
181}
182
183
184static int io_close (lua_State *L) {
185 if (lua_isnone(L, 1)) /* no argument? */
186 lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use standard output */
187 tofile(L); /* make sure argument is an open stream */
188 return aux_close(L);
189}
190
191
192static int f_gc (lua_State *L) {
193 LStream *p = tolstream(L);
194 if (!isclosed(p) && p->f != NULL)
195 aux_close(L); /* ignore closed and incompletely open files */
196 return 0;
197}
198
199
200/*
201** function to close regular files
202*/
203static int io_fclose (lua_State *L) {
204 LStream *p = tolstream(L);
205 int res = fclose(p->f);
206 return luaL_fileresult(L, (res == 0), NULL);
207}
208
209
210static LStream *newfile (lua_State *L) {
211 LStream *p = newprefile(L);
212 p->f = NULL;
213 p->closef = &io_fclose;
214 return p;
215}
216
217
218static void opencheck (lua_State *L, const char *fname, const char *mode) {
219 LStream *p = newfile(L);
220 p->f = fopen(fname, mode);
221 if (p->f == NULL)
222 luaL_error(L, "cannot open file " LUA_QS " (%s)", fname, strerror(errno));
223}
224
225
226static int io_open (lua_State *L) {
227 const char *filename = luaL_checkstring(L, 1);
228 const char *mode = luaL_optstring(L, 2, "r");
229 LStream *p = newfile(L);
230 const char *md = mode; /* to traverse/check mode */
231 luaL_argcheck(L, lua_checkmode(md), 2, "invalid mode");
232 p->f = fopen(filename, mode);
233 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
234}
235
236
237/*
238** function to close 'popen' files
239*/
240static int io_pclose (lua_State *L) {
241 LStream *p = tolstream(L);
242 return luaL_execresult(L, lua_pclose(L, p->f));
243}
244
245
246static int io_popen (lua_State *L) {
247 const char *filename = luaL_checkstring(L, 1);
248 const char *mode = luaL_optstring(L, 2, "r");
249 LStream *p = newprefile(L);
250 p->f = lua_popen(L, filename, mode);
251 p->closef = &io_pclose;
252 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
253}
254
255
256static int io_tmpfile (lua_State *L) {
257 LStream *p = newfile(L);
258 p->f = tmpfile();
259 return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
260}
261
262
263static FILE *getiofile (lua_State *L, const char *findex) {
264 LStream *p;
265 lua_getfield(L, LUA_REGISTRYINDEX, findex);
266 p = (LStream *)lua_touserdata(L, -1);
267 if (isclosed(p))
268 luaL_error(L, "standard %s file is closed", findex + strlen(IO_PREFIX));
269 return p->f;
270}
271
272
273static int g_iofile (lua_State *L, const char *f, const char *mode) {
274 if (!lua_isnoneornil(L, 1)) {
275 const char *filename = lua_tostring(L, 1);
276 if (filename)
277 opencheck(L, filename, mode);
278 else {
279 tofile(L); /* check that it's a valid file handle */
280 lua_pushvalue(L, 1);
281 }
282 lua_setfield(L, LUA_REGISTRYINDEX, f);
283 }
284 /* return current value */
285 lua_getfield(L, LUA_REGISTRYINDEX, f);
286 return 1;
287}
288
289
290static int io_input (lua_State *L) {
291 return g_iofile(L, IO_INPUT, "r");
292}
293
294
295static int io_output (lua_State *L) {
296 return g_iofile(L, IO_OUTPUT, "w");
297}
298
299
300static int io_readline (lua_State *L);
301
302
303static void aux_lines (lua_State *L, int toclose) {
304 int i;
305 int n = lua_gettop(L) - 1; /* number of arguments to read */
306 /* ensure that arguments will fit here and into 'io_readline' stack */
307 luaL_argcheck(L, n <= LUA_MINSTACK - 3, LUA_MINSTACK - 3, "too many options");
308 lua_pushvalue(L, 1); /* file handle */
309 lua_pushinteger(L, n); /* number of arguments to read */
310 lua_pushboolean(L, toclose); /* close/not close file when finished */
311 for (i = 1; i <= n; i++) lua_pushvalue(L, i + 1); /* copy arguments */
312 lua_pushcclosure(L, io_readline, 3 + n);
313}
314
315
316static int f_lines (lua_State *L) {
317 tofile(L); /* check that it's a valid file handle */
318 aux_lines(L, 0);
319 return 1;
320}
321
322
323static int io_lines (lua_State *L) {
324 int toclose;
325 if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */
326 if (lua_isnil(L, 1)) { /* no file name? */
327 lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */
328 lua_replace(L, 1); /* put it at index 1 */
329 tofile(L); /* check that it's a valid file handle */
330 toclose = 0; /* do not close it after iteration */
331 }
332 else { /* open a new file */
333 const char *filename = luaL_checkstring(L, 1);
334 opencheck(L, filename, "r");
335 lua_replace(L, 1); /* put file at index 1 */
336 toclose = 1; /* close it after iteration */
337 }
338 aux_lines(L, toclose);
339 return 1;
340}
341
342
343/*
344** {======================================================
345** READ
346** =======================================================
347*/
348
349
350static int read_number (lua_State *L, FILE *f) {
351 lua_Number d;
352 if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
353 lua_pushnumber(L, d);
354 return 1;
355 }
356 else {
357 lua_pushnil(L); /* "result" to be removed */
358 return 0; /* read fails */
359 }
360}
361
362
363static int test_eof (lua_State *L, FILE *f) {
364 int c = getc(f);
365 ungetc(c, f);
366 lua_pushlstring(L, NULL, 0);
367 return (c != EOF);
368}
369
370
371static int read_line (lua_State *L, FILE *f, int chop) {
372 luaL_Buffer b;
373 luaL_buffinit(L, &b);
374 for (;;) {
375 size_t l;
376 char *p = luaL_prepbuffer(&b);
377 if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */
378 luaL_pushresult(&b); /* close buffer */
379 return (lua_rawlen(L, -1) > 0); /* check whether read something */
380 }
381 l = strlen(p);
382 if (l == 0 || p[l-1] != '\n')
383 luaL_addsize(&b, l);
384 else {
385 luaL_addsize(&b, l - chop); /* chop 'eol' if needed */
386 luaL_pushresult(&b); /* close buffer */
387 return 1; /* read at least an `eol' */
388 }
389 }
390}
391
392
393#define MAX_SIZE_T (~(size_t)0)
394
395static void read_all (lua_State *L, FILE *f) {
396 size_t rlen = LUAL_BUFFERSIZE; /* how much to read in each cycle */
397 luaL_Buffer b;
398 luaL_buffinit(L, &b);
399 for (;;) {
400 char *p = luaL_prepbuffsize(&b, rlen);
401 size_t nr = fread(p, sizeof(char), rlen, f);
402 luaL_addsize(&b, nr);
403 if (nr < rlen) break; /* eof? */
404 else if (rlen <= (MAX_SIZE_T / 4)) /* avoid buffers too large */
405 rlen *= 2; /* double buffer size at each iteration */
406 }
407 luaL_pushresult(&b); /* close buffer */
408}
409
410
411static int read_chars (lua_State *L, FILE *f, size_t n) {
412 size_t nr; /* number of chars actually read */
413 char *p;
414 luaL_Buffer b;
415 luaL_buffinit(L, &b);
416 p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */
417 nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */
418 luaL_addsize(&b, nr);
419 luaL_pushresult(&b); /* close buffer */
420 return (nr > 0); /* true iff read something */
421}
422
423
424static int g_read (lua_State *L, FILE *f, int first) {
425 int nargs = lua_gettop(L) - 1;
426 int success;
427 int n;
428 clearerr(f);
429 if (nargs == 0) { /* no arguments? */
430 success = read_line(L, f, 1);
431 n = first+1; /* to return 1 result */
432 }
433 else { /* ensure stack space for all results and for auxlib's buffer */
434 luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
435 success = 1;
436 for (n = first; nargs-- && success; n++) {
437 if (lua_type(L, n) == LUA_TNUMBER) {
438 size_t l = (size_t)lua_tointeger(L, n);
439 success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
440 }
441 else {
442 const char *p = lua_tostring(L, n);
443 luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
444 switch (p[1]) {
445 case 'n': /* number */
446 success = read_number(L, f);
447 break;
448 case 'l': /* line */
449 success = read_line(L, f, 1);
450 break;
451 case 'L': /* line with end-of-line */
452 success = read_line(L, f, 0);
453 break;
454 case 'a': /* file */
455 read_all(L, f); /* read entire file */
456 success = 1; /* always success */
457 break;
458 default:
459 return luaL_argerror(L, n, "invalid format");
460 }
461 }
462 }
463 }
464 if (ferror(f))
465 return luaL_fileresult(L, 0, NULL);
466 if (!success) {
467 lua_pop(L, 1); /* remove last result */
468 lua_pushnil(L); /* push nil instead */
469 }
470 return n - first;
471}
472
473
474static int io_read (lua_State *L) {
475 return g_read(L, getiofile(L, IO_INPUT), 1);
476}
477
478
479static int f_read (lua_State *L) {
480 return g_read(L, tofile(L), 2);
481}
482
483
484static int io_readline (lua_State *L) {
485 LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
486 int i;
487 int n = (int)lua_tointeger(L, lua_upvalueindex(2));
488 if (isclosed(p)) /* file is already closed? */
489 return luaL_error(L, "file is already closed");
490 lua_settop(L , 1);
491 for (i = 1; i <= n; i++) /* push arguments to 'g_read' */
492 lua_pushvalue(L, lua_upvalueindex(3 + i));
493 n = g_read(L, p->f, 2); /* 'n' is number of results */
494 lua_assert(n > 0); /* should return at least a nil */
495 if (!lua_isnil(L, -n)) /* read at least one value? */
496 return n; /* return them */
497 else { /* first result is nil: EOF or error */
498 if (n > 1) { /* is there error information? */
499 /* 2nd result is error message */
500 return luaL_error(L, "%s", lua_tostring(L, -n + 1));
501 }
502 if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */
503 lua_settop(L, 0);
504 lua_pushvalue(L, lua_upvalueindex(1));
505 aux_close(L); /* close it */
506 }
507 return 0;
508 }
509}
510
511/* }====================================================== */
512
513
514static int g_write (lua_State *L, FILE *f, int arg) {
515 int nargs = lua_gettop(L) - arg;
516 int status = 1;
517 for (; nargs--; arg++) {
518 if (lua_type(L, arg) == LUA_TNUMBER) {
519 /* optimization: could be done exactly as for strings */
520 status = status &&
521 fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
522 }
523 else {
524 size_t l;
525 const char *s = luaL_checklstring(L, arg, &l);
526 status = status && (fwrite(s, sizeof(char), l, f) == l);
527 }
528 }
529 if (status) return 1; /* file handle already on stack top */
530 else return luaL_fileresult(L, status, NULL);
531}
532
533
534static int io_write (lua_State *L) {
535 return g_write(L, getiofile(L, IO_OUTPUT), 1);
536}
537
538
539static int f_write (lua_State *L) {
540 FILE *f = tofile(L);
541 lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */
542 return g_write(L, f, 2);
543}
544
545
546static int f_seek (lua_State *L) {
547 static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
548 static const char *const modenames[] = {"set", "cur", "end", NULL};
549 FILE *f = tofile(L);
550 int op = luaL_checkoption(L, 2, "cur", modenames);
551 lua_Number p3 = luaL_optnumber(L, 3, 0);
552 l_seeknum offset = (l_seeknum)p3;
553 luaL_argcheck(L, (lua_Number)offset == p3, 3,
554 "not an integer in proper range");
555 op = l_fseek(f, offset, mode[op]);
556 if (op)
557 return luaL_fileresult(L, 0, NULL); /* error */
558 else {
559 lua_pushnumber(L, (lua_Number)l_ftell(f));
560 return 1;
561 }
562}
563
564
565static int f_setvbuf (lua_State *L) {
566 static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
567 static const char *const modenames[] = {"no", "full", "line", NULL};
568 FILE *f = tofile(L);
569 int op = luaL_checkoption(L, 2, NULL, modenames);
570 lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
571 int res = setvbuf(f, NULL, mode[op], sz);
572 return luaL_fileresult(L, res == 0, NULL);
573}
574
575
576
577static int io_flush (lua_State *L) {
578 return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
579}
580
581
582static int f_flush (lua_State *L) {
583 return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);
584}
585
586
587/*
588** functions for 'io' library
589*/
590static const luaL_Reg iolib[] = {
591 {"close", io_close},
592 {"flush", io_flush},
593 {"input", io_input},
594 {"lines", io_lines},
595 {"open", io_open},
596 {"output", io_output},
597 {"popen", io_popen},
598 {"read", io_read},
599 {"tmpfile", io_tmpfile},
600 {"type", io_type},
601 {"write", io_write},
602 {NULL, NULL}
603};
604
605
606/*
607** methods for file handles
608*/
609static const luaL_Reg flib[] = {
610 {"close", io_close},
611 {"flush", f_flush},
612 {"lines", f_lines},
613 {"read", f_read},
614 {"seek", f_seek},
615 {"setvbuf", f_setvbuf},
616 {"write", f_write},
617 {"__gc", f_gc},
618 {"__tostring", f_tostring},
619 {NULL, NULL}
620};
621
622
623static void createmeta (lua_State *L) {
624 luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */
625 lua_pushvalue(L, -1); /* push metatable */
626 lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */
627 luaL_setfuncs(L, flib, 0); /* add file methods to new metatable */
628 lua_pop(L, 1); /* pop new metatable */
629}
630
631
632/*
633** function to (not) close the standard files stdin, stdout, and stderr
634*/
635static int io_noclose (lua_State *L) {
636 LStream *p = tolstream(L);
637 p->closef = &io_noclose; /* keep file opened */
638 lua_pushnil(L);
639 lua_pushliteral(L, "cannot close standard file");
640 return 2;
641}
642
643
644static void createstdfile (lua_State *L, FILE *f, const char *k,
645 const char *fname) {
646 LStream *p = newprefile(L);
647 p->f = f;
648 p->closef = &io_noclose;
649 if (k != NULL) {
650 lua_pushvalue(L, -1);
651 lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */
652 }
653 lua_setfield(L, -2, fname); /* add file to module */
654}
655
656
657LUAMOD_API int luaopen_io (lua_State *L) {
658 luaL_newlib(L, iolib); /* new module */
659 createmeta(L);
660 /* create (and set) default files */
661 createstdfile(L, stdin, IO_INPUT, "stdin");
662 createstdfile(L, stdout, IO_OUTPUT, "stdout");
663 createstdfile(L, stderr, NULL, "stderr");
664 return 1;
665}
666