Bug Summary

File:src/mod/languages/mod_lua/lua/liolib.c
Location:line 443, column 17
Description:Array access (from variable 'p') results in a null pointer dereference

Annotated Source Code

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_BITS64)
14#define _FILE_OFFSET_BITS64 64
15#endif
16
17
18#include <errno(*__errno_location ()).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)(*mode != '\0' && (__extension__ (__builtin_constant_p
(*(mode++)) && !__builtin_constant_p ("rwa") &&
(*(mode++)) == '\0' ? (char *) __rawmemchr ("rwa", *(mode++)
) : __builtin_strchr ("rwa", *(mode++)))) != ((void*)0) &&
(*mode != '+' || ++mode) && (*mode != 'b' || ++mode)
&& (*mode == '\0')) \
40 (*mode != '\0' && strchr("rwa", *(mode++))(__extension__ (__builtin_constant_p (*(mode++)) && !
__builtin_constant_p ("rwa") && (*(mode++)) == '\0' ?
(char *) __rawmemchr ("rwa", *(mode++)) : __builtin_strchr (
"rwa", *(mode++)))) != NULL((void*)0) && \
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(((void*)0)), popen(c,m)) ((void)L, fflush(NULL((void*)0)), popen(c,m))
59#define lua_pclose(L,file)((void)L, pclose(file)) ((void)L, pclose(file))
60
61#elif defined(LUA_WIN) /* }{ */
62
63#define lua_popen(L,c,m)((void)L, fflush(((void*)0)), popen(c,m)) ((void)L, _popen(c,m))
64#define lua_pclose(L,file)((void)L, pclose(file)) ((void)L, _pclose(file))
65
66
67#else /* }{ */
68
69#define lua_popen(L,c,m)((void)L, fflush(((void*)0)), popen(c,m)) ((void)((void)c, m), \
70 luaL_error(L, LUA_QL("popen")"'" "popen" "'" " not supported"), (FILE*)0)
71#define lua_pclose(L,file)((void)L, pclose(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) fseeko(f,o,w)
92#define l_ftell(f)ftello(f) ftello(f)
93#define l_seeknumoff_t 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)fseeko(f,o,w) _fseeki64(f,o,w)
100#define l_ftell(f)ftello(f) _ftelli64(f)
101#define l_seeknumoff_t __int64
102
103#else
104
105#define l_fseek(f,o,w)fseeko(f,o,w) fseek(f,o,w)
106#define l_ftell(f)ftello(f) ftell(f)
107#define l_seeknumoff_t long
108
109#endif
110
111#endif /* } */
112
113/* }====================================================== */
114
115
116#define IO_PREFIX"_IO_" "_IO_"
117#define IO_INPUT("_IO_" "input") (IO_PREFIX"_IO_" "input")
118#define IO_OUTPUT("_IO_" "output") (IO_PREFIX"_IO_" "output")
119
120
121typedef luaL_Stream LStream;
122
123
124#define tolstream(L)((LStream *)luaL_checkudata(L, 1, "FILE*")) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE"FILE*"))
125
126#define isclosed(p)((p)->closef == ((void*)0)) ((p)->closef == NULL((void*)0))
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"FILE*");
133 if (p == NULL((void*)0))
134 lua_pushnil(L); /* not a file */
135 else if (isclosed(p)((p)->closef == ((void*)0)))
136 lua_pushliteral(L, "closed file")lua_pushlstring(L, "" "closed file", (sizeof("closed file")/sizeof
(char))-1);
137 else
138 lua_pushliteral(L, "file")lua_pushlstring(L, "" "file", (sizeof("file")/sizeof(char))-1
);
139 return 1;
140}
141
142
143static int f_tostring (lua_State *L) {
144 LStream *p = tolstream(L)((LStream *)luaL_checkudata(L, 1, "FILE*"));
145 if (isclosed(p)((p)->closef == ((void*)0)))
146 lua_pushliteral(L, "file (closed)")lua_pushlstring(L, "" "file (closed)", (sizeof("file (closed)"
)/sizeof(char))-1);
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)((LStream *)luaL_checkudata(L, 1, "FILE*"));
155 if (isclosed(p)((p)->closef == ((void*)0)))
156 luaL_error(L, "attempt to use a closed file");
157 lua_assert(p->f)((void)0);
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((void*)0); /* mark file handle as 'closed' */
170 luaL_setmetatable(L, LUA_FILEHANDLE"FILE*");
171 return p;
172}
173
174
175static int aux_close (lua_State *L) {
176 LStream *p = tolstream(L)((LStream *)luaL_checkudata(L, 1, "FILE*"));
177 lua_CFunction cf = p->closef;
178 p->closef = NULL((void*)0); /* 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)(lua_type(L, (1)) == (-1))) /* no argument? */
185 lua_getfield(L, LUA_REGISTRYINDEX(-1000000 - 1000), IO_OUTPUT("_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)((LStream *)luaL_checkudata(L, 1, "FILE*"));
193 if (!isclosed(p)((p)->closef == ((void*)0)) && p->f != NULL((void*)0))
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)((LStream *)luaL_checkudata(L, 1, "FILE*"));
204 int res = fclose(p->f);
205 return luaL_fileresult(L, (res == 0), NULL((void*)0));
206}
207
208
209static LStream *newfile (lua_State *L) {
210 LStream *p = newprefile(L);
211 p->f = NULL((void*)0);
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((void*)0))
221 luaL_error(L, "cannot open file " LUA_QS"'" "%s" "'" " (%s)", fname, strerror(errno(*__errno_location ())));
222}
223
224
225static int io_open (lua_State *L) {
226 const char *filename = luaL_checkstring(L, 1)(luaL_checklstring(L, (1), ((void*)0)));
227 const char *mode = luaL_optstring(L, 2, "r")(luaL_optlstring(L, (2), ("r"), ((void*)0)));
228 LStream *p = newfile(L);
229 const char *md = mode; /* to traverse/check mode */
230 luaL_argcheck(L, lua_checkmode(md), 2, "invalid mode")((void)(((*md != '\0' && (__extension__ (__builtin_constant_p
(*(md++)) && !__builtin_constant_p ("rwa") &&
(*(md++)) == '\0' ? (char *) __rawmemchr ("rwa", *(md++)) : __builtin_strchr
("rwa", *(md++)))) != ((void*)0) && (*md != '+' || ++
md) && (*md != 'b' || ++md) && (*md == '\0'))
) || luaL_argerror(L, (2), ("invalid mode"))));
231 p->f = fopen(filename, mode);
232 return (p->f == NULL((void*)0)) ? 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)((LStream *)luaL_checkudata(L, 1, "FILE*"));
241 return luaL_execresult(L, lua_pclose(L, p->f)((void)L, pclose(p->f)));
242}
243
244
245static int io_popen (lua_State *L) {
246 const char *filename = luaL_checkstring(L, 1)(luaL_checklstring(L, (1), ((void*)0)));
247 const char *mode = luaL_optstring(L, 2, "r")(luaL_optlstring(L, (2), ("r"), ((void*)0)));
248 LStream *p = newprefile(L);
249 p->f = lua_popen(L, filename, mode)((void)L, fflush(((void*)0)), popen(filename,mode));
250 p->closef = &io_pclose;
251 return (p->f == NULL((void*)0)) ? 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((void*)0)) ? luaL_fileresult(L, 0, NULL((void*)0)) : 1;
259}
260
261
262static FILE *getiofile (lua_State *L, const char *findex) {
263 LStream *p;
264 lua_getfield(L, LUA_REGISTRYINDEX(-1000000 - 1000), findex);
265 p = (LStream *)lua_touserdata(L, -1);
266 if (isclosed(p)((p)->closef == ((void*)0)))
267 luaL_error(L, "standard %s file is closed", findex + strlen(IO_PREFIX"_IO_"));
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)(lua_type(L, (1)) <= 0)) {
274 const char *filename = lua_tostring(L, 1)lua_tolstring(L, (1), ((void*)0));
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(-1000000 - 1000), f);
282 }
283 /* return current value */
284 lua_getfield(L, LUA_REGISTRYINDEX(-1000000 - 1000), f);
285 return 1;
286}
287
288
289static int io_input (lua_State *L) {
290 return g_iofile(L, IO_INPUT("_IO_" "input"), "r");
291}
292
293
294static int io_output (lua_State *L) {
295 return g_iofile(L, IO_OUTPUT("_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")((void)((n <= 20 - 3) || luaL_argerror(L, (20 - 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_type(L, (1)) == (-1))) lua_pushnil(L); /* at least one argument */
325 if (lua_isnil(L, 1)(lua_type(L, (1)) == 0)) { /* no file name? */
326 lua_getfield(L, LUA_REGISTRYINDEX(-1000000 - 1000), IO_INPUT("_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)(luaL_checklstring(L, (1), ((void*)0)));
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"%lf", &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)_IO_getc (f);
364 ungetc(c, f);
365 lua_pushlstring(L, NULL((void*)0), 0);
366 return (c != EOF(-1));
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)luaL_prepbuffsize(&b, 8192);
376 if (fgets(p, LUAL_BUFFERSIZE8192, f) == NULL((void*)0)) { /* 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)((&b)->n += (l));
383 else {
384 luaL_addsize(&b, l - chop)((&b)->n += (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) (~(size_t)0)
393
394static void read_all (lua_State *L, FILE *f) {
395 size_t rlen = LUAL_BUFFERSIZE8192; /* 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)((&b)->n += (nr));
402 if (nr < rlen) break; /* eof? */
403 else if (rlen <= (MAX_SIZE_T(~(size_t)0) / 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)((&b)->n += (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? */
5
←
Assuming 'nargs' is not equal to 0
→
6
←
Taking false branch
→
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_MINSTACK20, "too many arguments");
434 success = 1;
435 for (n = first; nargs-- && success; n++) {
7
←
Loop condition is true. Entering loop body
→
436 if (lua_type(L, n) == LUA_TNUMBER3) {
8
←
Taking false branch
→
437 size_t l = (size_t)lua_tointeger(L, n)lua_tointegerx(L,n,((void*)0));
438 success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
439 }
440 else {
441 const char *p = lua_tostring(L, n)lua_tolstring(L, (n), ((void*)0));
9
←
'p' initialized here
→
442 luaL_argcheck(L, p && p[0] == '*', n, "invalid option")((void)((p && p[0] == '*') || luaL_argerror(L, (n), (
"invalid option"))));
10
←
Within the expansion of the macro 'luaL_argcheck':
→
a
Assuming pointer value is null
443 switch (p[1]) {
11
←
Array access (from variable 'p') results in a null pointer dereference
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((void*)0));
465 if (!success) {
466 lua_pop(L, 1)lua_settop(L, -(1)-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("_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)((-1000000 - 1000) - (1)));
485 int i;
486 int n = (int)lua_tointeger(L, lua_upvalueindex(2))lua_tointegerx(L,((-1000000 - 1000) - (2)),((void*)0));
487 if (isclosed(p)((p)->closef == ((void*)0))) /* file is already closed? */
1
Taking false branch
→
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' */
2
←
Assuming 'i' is > 'n'
→
3
←
Loop condition is false. Execution continues on line 492
→
491 lua_pushvalue(L, lua_upvalueindex(3 + i)((-1000000 - 1000) - (3 + i)));
492 n = g_read(L, p->f, 2); /* 'n' is number of results */
4
←
Calling 'g_read'
→
493 lua_assert(n > 0)((void)0); /* should return at least a nil */
494 if (!lua_isnil(L, -n)(lua_type(L, (-n)) == 0)) /* 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)lua_tolstring(L, (-n + 1), ((void*)0)));
500 }
501 if (lua_toboolean(L, lua_upvalueindex(3)((-1000000 - 1000) - (3)))) { /* generator created file? */
502 lua_settop(L, 0);
503 lua_pushvalue(L, lua_upvalueindex(1)((-1000000 - 1000) - (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_TNUMBER3) {
518 /* optimization: could be done exactly as for strings */
519 status = status &&
520 fprintf(f, LUA_NUMBER_FMT"%.14g", lua_tonumber(L, arg)lua_tonumberx(L,arg,((void*)0))) > 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((void*)0));
530}
531
532
533static int io_write (lua_State *L) {
534 return g_write(L, getiofile(L, IO_OUTPUT("_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_SET0, SEEK_CUR1, SEEK_END2};
547 static const char *const modenames[] = {"set", "cur", "end", NULL((void*)0)};
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_seeknumoff_t offset = (l_seeknumoff_t)p3;
552 luaL_argcheck(L, (lua_Number)offset == p3, 3,((void)(((lua_Number)offset == p3) || luaL_argerror(L, (3), (
"not an integer in proper range"))))
553 "not an integer in proper range")((void)(((lua_Number)offset == p3) || luaL_argerror(L, (3), (
"not an integer in proper range"))));
554 op = l_fseek(f, offset, mode[op])fseeko(f,offset,mode[op]);
555 if (op)
556 return luaL_fileresult(L, 0, NULL((void*)0)); /* error */
557 else {
558 lua_pushnumber(L, (lua_Number)l_ftell(f)ftello(f));
559 return 1;
560 }
561}
562
563
564static int f_setvbuf (lua_State *L) {
565 static const int mode[] = {_IONBF2, _IOFBF0, _IOLBF1};
566 static const char *const modenames[] = {"no", "full", "line", NULL((void*)0)};
567 FILE *f = tofile(L);
568 int op = luaL_checkoption(L, 2, NULL((void*)0), modenames);
569 lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE8192);
570 int res = setvbuf(f, NULL((void*)0), mode[op], sz);
571 return luaL_fileresult(L, res == 0, NULL((void*)0));
572}
573
574
575
576static int io_flush (lua_State *L) {
577 return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT("_IO_" "output"))) == 0, NULL((void*)0));
578}
579
580
581static int f_flush (lua_State *L) {
582 return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL((void*)0));
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((void*)0), NULL((void*)0)}
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((void*)0), NULL((void*)0)}
619};
620
621
622static void createmeta (lua_State *L) {
623 luaL_newmetatable(L, LUA_FILEHANDLE"FILE*"); /* 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)lua_settop(L, -(1)-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)((LStream *)luaL_checkudata(L, 1, "FILE*"));
636 p->closef = &io_noclose; /* keep file opened */
637 lua_pushnil(L);
638 lua_pushliteral(L, "cannot close standard file")lua_pushlstring(L, "" "cannot close standard file", (sizeof("cannot close standard file"
)/sizeof(char))-1);
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((void*)0)) {
649 lua_pushvalue(L, -1);
650 lua_setfield(L, LUA_REGISTRYINDEX(-1000000 - 1000), k); /* add file to registry */
651 }
652 lua_setfield(L, -2, fname); /* add file to module */
653}
654
655
656LUAMOD_API__attribute__((visibility("default"))) int luaopen_io (lua_State *L) {
657 luaL_newlib(L, iolib)(lua_createtable(L, 0, sizeof(iolib)/sizeof((iolib)[0]) - 1),
luaL_setfuncs(L,iolib,0)); /* new module */
658 createmeta(L);
659 /* create (and set) default files */
660 createstdfile(L, stdinstdin, IO_INPUT("_IO_" "input"), "stdin");
661 createstdfile(L, stdoutstdout, IO_OUTPUT("_IO_" "output"), "stdout");
662 createstdfile(L, stderrstderr, NULL((void*)0), "stderr");
663 return 1;
664}
665