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
667