1 /* 2 ** $Id: liolib.c $ 3 ** Standard I/O (and system) library 4 ** See Copyright Notice in lua.h 5 */ 6 7 #define liolib_c 8 #define LUA_LIB 9 10 #include "lprefix.h" 11 12 13 #include <ctype.h> 14 #include <errno.h> 15 #include <locale.h> 16 #include <stdio.h> 17 #include <stdlib.h> 18 #include <string.h> 19 20 #include "lua.h" 21 22 #include "lauxlib.h" 23 #include "lualib.h" 24 25 26 27 28 /* 29 ** Change this macro to accept other modes for 'fopen' besides 30 ** the standard ones. 31 */ 32 #if !defined(l_checkmode) 33 34 /* accepted extensions to 'mode' in 'fopen' */ 35 #if !defined(L_MODEEXT) 36 #define L_MODEEXT "b" 37 #endif 38 39 /* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */ 40 static int l_checkmode (const char *mode) { 41 return (*mode != '\0' && strchr("rwa", *(mode++)) != NULL && 42 (*mode != '+' || ((void)(++mode), 1)) && /* skip if char is '+' */ 43 (strspn(mode, L_MODEEXT) == strlen(mode))); /* check extensions */ 44 } 45 46 #endif 47 48 /* 49 ** {====================================================== 50 ** l_popen spawns a new process connected to the current 51 ** one through the file streams. 52 ** ======================================================= 53 */ 54 55 #if !defined(l_popen) /* { */ 56 57 #if defined(LUA_USE_POSIX) /* { */ 58 59 #define l_popen(L,c,m) (fflush(NULL), popen(c,m)) 60 #define l_pclose(L,file) (pclose(file)) 61 62 #elif defined(LUA_USE_WINDOWS) /* }{ */ 63 64 #define l_popen(L,c,m) (_popen(c,m)) 65 #define l_pclose(L,file) (_pclose(file)) 66 67 #if !defined(l_checkmodep) 68 /* Windows accepts "[rw][bt]?" as valid modes */ 69 #define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && \ 70 (m[1] == '\0' || ((m[1] == 'b' || m[1] == 't') && m[2] == '\0'))) 71 #endif 72 73 #else /* }{ */ 74 75 /* ISO C definitions */ 76 #define l_popen(L,c,m) \ 77 ((void)c, (void)m, \ 78 luaL_error(L, "'popen' not supported"), \ 79 (FILE*)0) 80 #define l_pclose(L,file) ((void)L, (void)file, -1) 81 82 #endif /* } */ 83 84 #endif /* } */ 85 86 87 #if !defined(l_checkmodep) 88 /* By default, Lua accepts only "r" or "w" as valid modes */ 89 #define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0') 90 #endif 91 92 /* }====================================================== */ 93 94 95 #if !defined(l_getc) /* { */ 96 97 #if defined(LUA_USE_POSIX) 98 #define l_getc(f) getc_unlocked(f) 99 #define l_lockfile(f) flockfile(f) 100 #define l_unlockfile(f) funlockfile(f) 101 #else 102 #define l_getc(f) getc(f) 103 #define l_lockfile(f) ((void)0) 104 #define l_unlockfile(f) ((void)0) 105 #endif 106 107 #endif /* } */ 108 109 110 /* 111 ** {====================================================== 112 ** l_fseek: configuration for longer offsets 113 ** ======================================================= 114 */ 115 116 #if !defined(l_fseek) /* { */ 117 118 #if defined(LUA_USE_POSIX) /* { */ 119 120 #include <sys/types.h> 121 122 #define l_fseek(f,o,w) fseeko(f,o,w) 123 #define l_ftell(f) ftello(f) 124 #define l_seeknum off_t 125 126 #elif defined(LUA_USE_WINDOWS) && !defined(_CRTIMP_TYPEINFO) \ 127 && defined(_MSC_VER) && (_MSC_VER >= 1400) /* }{ */ 128 129 /* Windows (but not DDK) and Visual C++ 2005 or higher */ 130 #define l_fseek(f,o,w) _fseeki64(f,o,w) 131 #define l_ftell(f) _ftelli64(f) 132 #define l_seeknum __int64 133 134 #else /* }{ */ 135 136 /* ISO C definitions */ 137 #define l_fseek(f,o,w) fseek(f,o,w) 138 #define l_ftell(f) ftell(f) 139 #define l_seeknum long 140 141 #endif /* } */ 142 143 #endif /* } */ 144 145 /* }====================================================== */ 146 147 148 149 #define IO_PREFIX "_IO_" 150 #define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1) 151 #define IO_INPUT (IO_PREFIX "input") 152 #define IO_OUTPUT (IO_PREFIX "output") 153 154 155 typedef luaL_Stream LStream; 156 157 158 #define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE)) 159 160 #define isclosed(p) ((p)->closef == NULL) 161 162 163 static int io_type (lua_State *L) { 164 LStream *p; 165 luaL_checkany(L, 1); 166 p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE); 167 if (p == NULL) 168 luaL_pushfail(L); /* not a file */ 169 else if (isclosed(p)) 170 lua_pushliteral(L, "closed file"); 171 else 172 lua_pushliteral(L, "file"); 173 return 1; 174 } 175 176 177 static int f_tostring (lua_State *L) { 178 LStream *p = tolstream(L); 179 if (isclosed(p)) 180 lua_pushliteral(L, "file (closed)"); 181 else 182 lua_pushfstring(L, "file (%p)", p->f); 183 return 1; 184 } 185 186 187 static FILE *tofile (lua_State *L) { 188 LStream *p = tolstream(L); 189 if (l_unlikely(isclosed(p))) 190 luaL_error(L, "attempt to use a closed file"); 191 lua_assert(p->f); 192 return p->f; 193 } 194 195 196 /* 197 ** When creating file handles, always creates a 'closed' file handle 198 ** before opening the actual file; so, if there is a memory error, the 199 ** handle is in a consistent state. 200 */ 201 static LStream *newprefile (lua_State *L) { 202 LStream *p = (LStream *)lua_newuserdatauv(L, sizeof(LStream), 0); 203 p->closef = NULL; /* mark file handle as 'closed' */ 204 luaL_setmetatable(L, LUA_FILEHANDLE); 205 return p; 206 } 207 208 209 /* 210 ** Calls the 'close' function from a file handle. The 'volatile' avoids 211 ** a bug in some versions of the Clang compiler (e.g., clang 3.0 for 212 ** 32 bits). 213 */ 214 static int aux_close (lua_State *L) { 215 LStream *p = tolstream(L); 216 volatile lua_CFunction cf = p->closef; 217 p->closef = NULL; /* mark stream as closed */ 218 return (*cf)(L); /* close it */ 219 } 220 221 222 static int f_close (lua_State *L) { 223 tofile(L); /* make sure argument is an open stream */ 224 return aux_close(L); 225 } 226 227 228 static int io_close (lua_State *L) { 229 if (lua_isnone(L, 1)) /* no argument? */ 230 lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use default output */ 231 return f_close(L); 232 } 233 234 235 static int f_gc (lua_State *L) { 236 LStream *p = tolstream(L); 237 if (!isclosed(p) && p->f != NULL) 238 aux_close(L); /* ignore closed and incompletely open files */ 239 return 0; 240 } 241 242 243 /* 244 ** function to close regular files 245 */ 246 static int io_fclose (lua_State *L) { 247 LStream *p = tolstream(L); 248 errno = 0; 249 return luaL_fileresult(L, (fclose(p->f) == 0), NULL); 250 } 251 252 253 static LStream *newfile (lua_State *L) { 254 LStream *p = newprefile(L); 255 p->f = NULL; 256 p->closef = &io_fclose; 257 return p; 258 } 259 260 261 static void opencheck (lua_State *L, const char *fname, const char *mode) { 262 LStream *p = newfile(L); 263 p->f = fopen(fname, mode); 264 if (l_unlikely(p->f == NULL)) 265 luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno)); 266 } 267 268 269 static int io_open (lua_State *L) { 270 const char *filename = luaL_checkstring(L, 1); 271 const char *mode = luaL_optstring(L, 2, "r"); 272 LStream *p = newfile(L); 273 const char *md = mode; /* to traverse/check mode */ 274 luaL_argcheck(L, l_checkmode(md), 2, "invalid mode"); 275 errno = 0; 276 p->f = fopen(filename, mode); 277 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; 278 } 279 280 281 /* 282 ** function to close 'popen' files 283 */ 284 static int io_pclose (lua_State *L) { 285 LStream *p = tolstream(L); 286 errno = 0; 287 return luaL_execresult(L, l_pclose(L, p->f)); 288 } 289 290 291 static int io_popen (lua_State *L) { 292 const char *filename = luaL_checkstring(L, 1); 293 const char *mode = luaL_optstring(L, 2, "r"); 294 LStream *p = newprefile(L); 295 luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode"); 296 errno = 0; 297 p->f = l_popen(L, filename, mode); 298 p->closef = &io_pclose; 299 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; 300 } 301 302 303 static int io_tmpfile (lua_State *L) { 304 LStream *p = newfile(L); 305 errno = 0; 306 p->f = tmpfile(); 307 return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; 308 } 309 310 311 static FILE *getiofile (lua_State *L, const char *findex) { 312 LStream *p; 313 lua_getfield(L, LUA_REGISTRYINDEX, findex); 314 p = (LStream *)lua_touserdata(L, -1); 315 if (l_unlikely(isclosed(p))) 316 luaL_error(L, "default %s file is closed", findex + IOPREF_LEN); 317 return p->f; 318 } 319 320 321 static int g_iofile (lua_State *L, const char *f, const char *mode) { 322 if (!lua_isnoneornil(L, 1)) { 323 const char *filename = lua_tostring(L, 1); 324 if (filename) 325 opencheck(L, filename, mode); 326 else { 327 tofile(L); /* check that it's a valid file handle */ 328 lua_pushvalue(L, 1); 329 } 330 lua_setfield(L, LUA_REGISTRYINDEX, f); 331 } 332 /* return current value */ 333 lua_getfield(L, LUA_REGISTRYINDEX, f); 334 return 1; 335 } 336 337 338 static int io_input (lua_State *L) { 339 return g_iofile(L, IO_INPUT, "r"); 340 } 341 342 343 static int io_output (lua_State *L) { 344 return g_iofile(L, IO_OUTPUT, "w"); 345 } 346 347 348 static int io_readline (lua_State *L); 349 350 351 /* 352 ** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit 353 ** in the limit for upvalues of a closure) 354 */ 355 #define MAXARGLINE 250 356 357 /* 358 ** Auxiliary function to create the iteration function for 'lines'. 359 ** The iteration function is a closure over 'io_readline', with 360 ** the following upvalues: 361 ** 1) The file being read (first value in the stack) 362 ** 2) the number of arguments to read 363 ** 3) a boolean, true iff file has to be closed when finished ('toclose') 364 ** *) a variable number of format arguments (rest of the stack) 365 */ 366 static void aux_lines (lua_State *L, int toclose) { 367 int n = lua_gettop(L) - 1; /* number of arguments to read */ 368 luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments"); 369 lua_pushvalue(L, 1); /* file */ 370 lua_pushinteger(L, n); /* number of arguments to read */ 371 lua_pushboolean(L, toclose); /* close/not close file when finished */ 372 lua_rotate(L, 2, 3); /* move the three values to their positions */ 373 lua_pushcclosure(L, io_readline, 3 + n); 374 } 375 376 377 static int f_lines (lua_State *L) { 378 tofile(L); /* check that it's a valid file handle */ 379 aux_lines(L, 0); 380 return 1; 381 } 382 383 384 /* 385 ** Return an iteration function for 'io.lines'. If file has to be 386 ** closed, also returns the file itself as a second result (to be 387 ** closed as the state at the exit of a generic for). 388 */ 389 static int io_lines (lua_State *L) { 390 int toclose; 391 if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */ 392 if (lua_isnil(L, 1)) { /* no file name? */ 393 lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */ 394 lua_replace(L, 1); /* put it at index 1 */ 395 tofile(L); /* check that it's a valid file handle */ 396 toclose = 0; /* do not close it after iteration */ 397 } 398 else { /* open a new file */ 399 const char *filename = luaL_checkstring(L, 1); 400 opencheck(L, filename, "r"); 401 lua_replace(L, 1); /* put file at index 1 */ 402 toclose = 1; /* close it after iteration */ 403 } 404 aux_lines(L, toclose); /* push iteration function */ 405 if (toclose) { 406 lua_pushnil(L); /* state */ 407 lua_pushnil(L); /* control */ 408 lua_pushvalue(L, 1); /* file is the to-be-closed variable (4th result) */ 409 return 4; 410 } 411 else 412 return 1; 413 } 414 415 416 /* 417 ** {====================================================== 418 ** READ 419 ** ======================================================= 420 */ 421 422 423 /* maximum length of a numeral */ 424 #if !defined (L_MAXLENNUM) 425 #define L_MAXLENNUM 200 426 #endif 427 428 429 /* auxiliary structure used by 'read_number' */ 430 typedef struct { 431 FILE *f; /* file being read */ 432 int c; /* current character (look ahead) */ 433 int n; /* number of elements in buffer 'buff' */ 434 char buff[L_MAXLENNUM + 1]; /* +1 for ending '\0' */ 435 } RN; 436 437 438 /* 439 ** Add current char to buffer (if not out of space) and read next one 440 */ 441 static int nextc (RN *rn) { 442 if (l_unlikely(rn->n >= L_MAXLENNUM)) { /* buffer overflow? */ 443 rn->buff[0] = '\0'; /* invalidate result */ 444 return 0; /* fail */ 445 } 446 else { 447 rn->buff[rn->n++] = rn->c; /* save current char */ 448 rn->c = l_getc(rn->f); /* read next one */ 449 return 1; 450 } 451 } 452 453 454 /* 455 ** Accept current char if it is in 'set' (of size 2) 456 */ 457 static int test2 (RN *rn, const char *set) { 458 if (rn->c == set[0] || rn->c == set[1]) 459 return nextc(rn); 460 else return 0; 461 } 462 463 464 /* 465 ** Read a sequence of (hex)digits 466 */ 467 static int readdigits (RN *rn, int hex) { 468 int count = 0; 469 while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn)) 470 count++; 471 return count; 472 } 473 474 475 /* 476 ** Read a number: first reads a valid prefix of a numeral into a buffer. 477 ** Then it calls 'lua_stringtonumber' to check whether the format is 478 ** correct and to convert it to a Lua number. 479 */ 480 static int read_number (lua_State *L, FILE *f) { 481 RN rn; 482 int count = 0; 483 int hex = 0; 484 char decp[2]; 485 rn.f = f; rn.n = 0; 486 decp[0] = lua_getlocaledecpoint(); /* get decimal point from locale */ 487 decp[1] = '.'; /* always accept a dot */ 488 l_lockfile(rn.f); 489 do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */ 490 test2(&rn, "-+"); /* optional sign */ 491 if (test2(&rn, "00")) { 492 if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */ 493 else count = 1; /* count initial '0' as a valid digit */ 494 } 495 count += readdigits(&rn, hex); /* integral part */ 496 if (test2(&rn, decp)) /* decimal point? */ 497 count += readdigits(&rn, hex); /* fractional part */ 498 if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */ 499 test2(&rn, "-+"); /* exponent sign */ 500 readdigits(&rn, 0); /* exponent digits */ 501 } 502 ungetc(rn.c, rn.f); /* unread look-ahead char */ 503 l_unlockfile(rn.f); 504 rn.buff[rn.n] = '\0'; /* finish string */ 505 if (l_likely(lua_stringtonumber(L, rn.buff))) 506 return 1; /* ok, it is a valid number */ 507 else { /* invalid format */ 508 lua_pushnil(L); /* "result" to be removed */ 509 return 0; /* read fails */ 510 } 511 } 512 513 514 static int test_eof (lua_State *L, FILE *f) { 515 int c = getc(f); 516 ungetc(c, f); /* no-op when c == EOF */ 517 lua_pushliteral(L, ""); 518 return (c != EOF); 519 } 520 521 522 static int read_line (lua_State *L, FILE *f, int chop) { 523 luaL_Buffer b; 524 int c; 525 luaL_buffinit(L, &b); 526 do { /* may need to read several chunks to get whole line */ 527 char *buff = luaL_prepbuffer(&b); /* preallocate buffer space */ 528 int i = 0; 529 l_lockfile(f); /* no memory errors can happen inside the lock */ 530 while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n') 531 buff[i++] = c; /* read up to end of line or buffer limit */ 532 l_unlockfile(f); 533 luaL_addsize(&b, i); 534 } while (c != EOF && c != '\n'); /* repeat until end of line */ 535 if (!chop && c == '\n') /* want a newline and have one? */ 536 luaL_addchar(&b, c); /* add ending newline to result */ 537 luaL_pushresult(&b); /* close buffer */ 538 /* return ok if read something (either a newline or something else) */ 539 return (c == '\n' || lua_rawlen(L, -1) > 0); 540 } 541 542 543 static void read_all (lua_State *L, FILE *f) { 544 size_t nr; 545 luaL_Buffer b; 546 luaL_buffinit(L, &b); 547 do { /* read file in chunks of LUAL_BUFFERSIZE bytes */ 548 char *p = luaL_prepbuffer(&b); 549 nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f); 550 luaL_addsize(&b, nr); 551 } while (nr == LUAL_BUFFERSIZE); 552 luaL_pushresult(&b); /* close buffer */ 553 } 554 555 556 static int read_chars (lua_State *L, FILE *f, size_t n) { 557 size_t nr; /* number of chars actually read */ 558 char *p; 559 luaL_Buffer b; 560 luaL_buffinit(L, &b); 561 p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */ 562 nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */ 563 luaL_addsize(&b, nr); 564 luaL_pushresult(&b); /* close buffer */ 565 return (nr > 0); /* true iff read something */ 566 } 567 568 569 static int g_read (lua_State *L, FILE *f, int first) { 570 int nargs = lua_gettop(L) - 1; 571 int n, success; 572 clearerr(f); 573 errno = 0; 574 if (nargs == 0) { /* no arguments? */ 575 success = read_line(L, f, 1); 576 n = first + 1; /* to return 1 result */ 577 } 578 else { 579 /* ensure stack space for all results and for auxlib's buffer */ 580 luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); 581 success = 1; 582 for (n = first; nargs-- && success; n++) { 583 if (lua_type(L, n) == LUA_TNUMBER) { 584 size_t l = (size_t)luaL_checkinteger(L, n); 585 success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); 586 } 587 else { 588 const char *p = luaL_checkstring(L, n); 589 if (*p == '*') p++; /* skip optional '*' (for compatibility) */ 590 switch (*p) { 591 case 'n': /* number */ 592 success = read_number(L, f); 593 break; 594 case 'l': /* line */ 595 success = read_line(L, f, 1); 596 break; 597 case 'L': /* line with end-of-line */ 598 success = read_line(L, f, 0); 599 break; 600 case 'a': /* file */ 601 read_all(L, f); /* read entire file */ 602 success = 1; /* always success */ 603 break; 604 default: 605 return luaL_argerror(L, n, "invalid format"); 606 } 607 } 608 } 609 } 610 if (ferror(f)) 611 return luaL_fileresult(L, 0, NULL); 612 if (!success) { 613 lua_pop(L, 1); /* remove last result */ 614 luaL_pushfail(L); /* push nil instead */ 615 } 616 return n - first; 617 } 618 619 620 static int io_read (lua_State *L) { 621 return g_read(L, getiofile(L, IO_INPUT), 1); 622 } 623 624 625 static int f_read (lua_State *L) { 626 return g_read(L, tofile(L), 2); 627 } 628 629 630 /* 631 ** Iteration function for 'lines'. 632 */ 633 static int io_readline (lua_State *L) { 634 LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1)); 635 int i; 636 int n = (int)lua_tointeger(L, lua_upvalueindex(2)); 637 if (isclosed(p)) /* file is already closed? */ 638 return luaL_error(L, "file is already closed"); 639 lua_settop(L , 1); 640 luaL_checkstack(L, n, "too many arguments"); 641 for (i = 1; i <= n; i++) /* push arguments to 'g_read' */ 642 lua_pushvalue(L, lua_upvalueindex(3 + i)); 643 n = g_read(L, p->f, 2); /* 'n' is number of results */ 644 lua_assert(n > 0); /* should return at least a nil */ 645 if (lua_toboolean(L, -n)) /* read at least one value? */ 646 return n; /* return them */ 647 else { /* first result is false: EOF or error */ 648 if (n > 1) { /* is there error information? */ 649 /* 2nd result is error message */ 650 return luaL_error(L, "%s", lua_tostring(L, -n + 1)); 651 } 652 if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */ 653 lua_settop(L, 0); /* clear stack */ 654 lua_pushvalue(L, lua_upvalueindex(1)); /* push file at index 1 */ 655 aux_close(L); /* close it */ 656 } 657 return 0; 658 } 659 } 660 661 /* }====================================================== */ 662 663 664 static int g_write (lua_State *L, FILE *f, int arg) { 665 int nargs = lua_gettop(L) - arg; 666 int status = 1; 667 errno = 0; 668 for (; nargs--; arg++) { 669 if (lua_type(L, arg) == LUA_TNUMBER) { 670 /* optimization: could be done exactly as for strings */ 671 int len = lua_isinteger(L, arg) 672 ? fprintf(f, LUA_INTEGER_FMT, 673 (LUAI_UACINT)lua_tointeger(L, arg)) 674 : fprintf(f, LUA_NUMBER_FMT, 675 (LUAI_UACNUMBER)lua_tonumber(L, arg)); 676 status = status && (len > 0); 677 } 678 else { 679 size_t l; 680 const char *s = luaL_checklstring(L, arg, &l); 681 status = status && (fwrite(s, sizeof(char), l, f) == l); 682 } 683 } 684 if (l_likely(status)) 685 return 1; /* file handle already on stack top */ 686 else 687 return luaL_fileresult(L, status, NULL); 688 } 689 690 691 static int io_write (lua_State *L) { 692 return g_write(L, getiofile(L, IO_OUTPUT), 1); 693 } 694 695 696 static int f_write (lua_State *L) { 697 FILE *f = tofile(L); 698 lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */ 699 return g_write(L, f, 2); 700 } 701 702 703 static int f_seek (lua_State *L) { 704 static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; 705 static const char *const modenames[] = {"set", "cur", "end", NULL}; 706 FILE *f = tofile(L); 707 int op = luaL_checkoption(L, 2, "cur", modenames); 708 lua_Integer p3 = luaL_optinteger(L, 3, 0); 709 l_seeknum offset = (l_seeknum)p3; 710 luaL_argcheck(L, (lua_Integer)offset == p3, 3, 711 "not an integer in proper range"); 712 errno = 0; 713 op = l_fseek(f, offset, mode[op]); 714 if (l_unlikely(op)) 715 return luaL_fileresult(L, 0, NULL); /* error */ 716 else { 717 lua_pushinteger(L, (lua_Integer)l_ftell(f)); 718 return 1; 719 } 720 } 721 722 723 static int f_setvbuf (lua_State *L) { 724 static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; 725 static const char *const modenames[] = {"no", "full", "line", NULL}; 726 FILE *f = tofile(L); 727 int op = luaL_checkoption(L, 2, NULL, modenames); 728 lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); 729 int res; 730 errno = 0; 731 res = setvbuf(f, NULL, mode[op], (size_t)sz); 732 return luaL_fileresult(L, res == 0, NULL); 733 } 734 735 736 737 static int io_flush (lua_State *L) { 738 FILE *f = getiofile(L, IO_OUTPUT); 739 errno = 0; 740 return luaL_fileresult(L, fflush(f) == 0, NULL); 741 } 742 743 744 static int f_flush (lua_State *L) { 745 FILE *f = tofile(L); 746 errno = 0; 747 return luaL_fileresult(L, fflush(f) == 0, NULL); 748 } 749 750 751 /* 752 ** functions for 'io' library 753 */ 754 static const luaL_Reg iolib[] = { 755 {"close", io_close}, 756 {"flush", io_flush}, 757 {"input", io_input}, 758 {"lines", io_lines}, 759 {"open", io_open}, 760 {"output", io_output}, 761 {"popen", io_popen}, 762 {"read", io_read}, 763 {"tmpfile", io_tmpfile}, 764 {"type", io_type}, 765 {"write", io_write}, 766 {NULL, NULL} 767 }; 768 769 770 /* 771 ** methods for file handles 772 */ 773 static const luaL_Reg meth[] = { 774 {"read", f_read}, 775 {"write", f_write}, 776 {"lines", f_lines}, 777 {"flush", f_flush}, 778 {"seek", f_seek}, 779 {"close", f_close}, 780 {"setvbuf", f_setvbuf}, 781 {NULL, NULL} 782 }; 783 784 785 /* 786 ** metamethods for file handles 787 */ 788 static const luaL_Reg metameth[] = { 789 {"__index", NULL}, /* placeholder */ 790 {"__gc", f_gc}, 791 {"__close", f_gc}, 792 {"__tostring", f_tostring}, 793 {NULL, NULL} 794 }; 795 796 797 static void createmeta (lua_State *L) { 798 luaL_newmetatable(L, LUA_FILEHANDLE); /* metatable for file handles */ 799 luaL_setfuncs(L, metameth, 0); /* add metamethods to new metatable */ 800 luaL_newlibtable(L, meth); /* create method table */ 801 luaL_setfuncs(L, meth, 0); /* add file methods to method table */ 802 lua_setfield(L, -2, "__index"); /* metatable.__index = method table */ 803 lua_pop(L, 1); /* pop metatable */ 804 } 805 806 807 /* 808 ** function to (not) close the standard files stdin, stdout, and stderr 809 */ 810 static int io_noclose (lua_State *L) { 811 LStream *p = tolstream(L); 812 p->closef = &io_noclose; /* keep file opened */ 813 luaL_pushfail(L); 814 lua_pushliteral(L, "cannot close standard file"); 815 return 2; 816 } 817 818 819 static void createstdfile (lua_State *L, FILE *f, const char *k, 820 const char *fname) { 821 LStream *p = newprefile(L); 822 p->f = f; 823 p->closef = &io_noclose; 824 if (k != NULL) { 825 lua_pushvalue(L, -1); 826 lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */ 827 } 828 lua_setfield(L, -2, fname); /* add file to module */ 829 } 830 831 832 LUAMOD_API int luaopen_io (lua_State *L) { 833 luaL_newlib(L, iolib); /* new module */ 834 createmeta(L); 835 /* create (and set) default files */ 836 createstdfile(L, stdin, IO_INPUT, "stdin"); 837 createstdfile(L, stdout, IO_OUTPUT, "stdout"); 838 createstdfile(L, stderr, NULL, "stderr"); 839 return 1; 840 } 841 842