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
121typedef 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
129static 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
143static 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
153static 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*/
167static 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
175static 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
183static 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
191static 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*/
202static 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
209static 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
217static 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
225static 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*/
239static int io_pclose (lua_State *L) {
240  LStream *p = tolstream(L);
241  return luaL_execresult(L, lua_pclose(L, p->f));
242}
243
244
245static 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
255static 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
262static 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
272static 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
289static int io_input (lua_State *L) {
290  return g_iofile(L, IO_INPUT, "r");
291}
292
293
294static int io_output (lua_State *L) {
295  return g_iofile(L, IO_OUTPUT, "w");
296}
297
298
299static int io_readline (lua_State *L);
300
301
302static 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
315static 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
322static 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
349static 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
362static 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
370static 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
394static 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
410static 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
423static 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
473static int io_read (lua_State *L) {
474  return g_read(L, getiofile(L, IO_INPUT), 1);
475}
476
477
478static int f_read (lua_State *L) {
479  return g_read(L, tofile(L), 2);
480}
481
482
483static 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
513static 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
533static int io_write (lua_State *L) {
534  return g_write(L, getiofile(L, IO_OUTPUT), 1);
535}
536
537
538static 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
545static 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
564static 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
576static int io_flush (lua_State *L) {
577  return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
578}
579
580
581static 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*/
589static 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*/
608static 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
622static 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*/
634static 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
643static 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
656LUAMOD_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