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 int res = fclose(p->f); 249 return luaL_fileresult(L, (res == 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 p->f = fopen(filename, mode); 276 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; 277 } 278 279 280 /* 281 ** function to close 'popen' files 282 */ 283 static int io_pclose (lua_State *L) { 284 LStream *p = tolstream(L); 285 errno = 0; 286 return luaL_execresult(L, l_pclose(L, p->f)); 287 } 288 289 290 static int io_popen (lua_State *L) { 291 const char *filename = luaL_checkstring(L, 1); 292 const char *mode = luaL_optstring(L, 2, "r"); 293 LStream *p = newprefile(L); 294 luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode"); 295 p->f = l_popen(L, filename, mode); 296 p->closef = &io_pclose; 297 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; 298 } 299 300 301 static int io_tmpfile (lua_State *L) { 302 LStream *p = newfile(L); 303 p->f = tmpfile(); 304 return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; 305 } 306 307 308 static FILE *getiofile (lua_State *L, const char *findex) { 309 LStream *p; 310 lua_getfield(L, LUA_REGISTRYINDEX, findex); 311 p = (LStream *)lua_touserdata(L, -1); 312 if (l_unlikely(isclosed(p))) 313 luaL_error(L, "default %s file is closed", findex + IOPREF_LEN); 314 return p->f; 315 } 316 317 318 static int g_iofile (lua_State *L, const char *f, const char *mode) { 319 if (!lua_isnoneornil(L, 1)) { 320 const char *filename = lua_tostring(L, 1); 321 if (filename) 322 opencheck(L, filename, mode); 323 else { 324 tofile(L); /* check that it's a valid file handle */ 325 lua_pushvalue(L, 1); 326 } 327 lua_setfield(L, LUA_REGISTRYINDEX, f); 328 } 329 /* return current value */ 330 lua_getfield(L, LUA_REGISTRYINDEX, f); 331 return 1; 332 } 333 334 335 static int io_input (lua_State *L) { 336 return g_iofile(L, IO_INPUT, "r"); 337 } 338 339 340 static int io_output (lua_State *L) { 341 return g_iofile(L, IO_OUTPUT, "w"); 342 } 343 344 345 static int io_readline (lua_State *L); 346 347 348 /* 349 ** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit 350 ** in the limit for upvalues of a closure) 351 */ 352 #define MAXARGLINE 250 353 354 /* 355 ** Auxiliary function to create the iteration function for 'lines'. 356 ** The iteration function is a closure over 'io_readline', with 357 ** the following upvalues: 358 ** 1) The file being read (first value in the stack) 359 ** 2) the number of arguments to read 360 ** 3) a boolean, true iff file has to be closed when finished ('toclose') 361 ** *) a variable number of format arguments (rest of the stack) 362 */ 363 static void aux_lines (lua_State *L, int toclose) { 364 int n = lua_gettop(L) - 1; /* number of arguments to read */ 365 luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments"); 366 lua_pushvalue(L, 1); /* file */ 367 lua_pushinteger(L, n); /* number of arguments to read */ 368 lua_pushboolean(L, toclose); /* close/not close file when finished */ 369 lua_rotate(L, 2, 3); /* move the three values to their positions */ 370 lua_pushcclosure(L, io_readline, 3 + n); 371 } 372 373 374 static int f_lines (lua_State *L) { 375 tofile(L); /* check that it's a valid file handle */ 376 aux_lines(L, 0); 377 return 1; 378 } 379 380 381 /* 382 ** Return an iteration function for 'io.lines'. If file has to be 383 ** closed, also returns the file itself as a second result (to be 384 ** closed as the state at the exit of a generic for). 385 */ 386 static int io_lines (lua_State *L) { 387 int toclose; 388 if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */ 389 if (lua_isnil(L, 1)) { /* no file name? */ 390 lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */ 391 lua_replace(L, 1); /* put it at index 1 */ 392 tofile(L); /* check that it's a valid file handle */ 393 toclose = 0; /* do not close it after iteration */ 394 } 395 else { /* open a new file */ 396 const char *filename = luaL_checkstring(L, 1); 397 opencheck(L, filename, "r"); 398 lua_replace(L, 1); /* put file at index 1 */ 399 toclose = 1; /* close it after iteration */ 400 } 401 aux_lines(L, toclose); /* push iteration function */ 402 if (toclose) { 403 lua_pushnil(L); /* state */ 404 lua_pushnil(L); /* control */ 405 lua_pushvalue(L, 1); /* file is the to-be-closed variable (4th result) */ 406 return 4; 407 } 408 else 409 return 1; 410 } 411 412 413 /* 414 ** {====================================================== 415 ** READ 416 ** ======================================================= 417 */ 418 419 420 /* maximum length of a numeral */ 421 #if !defined (L_MAXLENNUM) 422 #define L_MAXLENNUM 200 423 #endif 424 425 426 /* auxiliary structure used by 'read_number' */ 427 typedef struct { 428 FILE *f; /* file being read */ 429 int c; /* current character (look ahead) */ 430 int n; /* number of elements in buffer 'buff' */ 431 char buff[L_MAXLENNUM + 1]; /* +1 for ending '\0' */ 432 } RN; 433 434 435 /* 436 ** Add current char to buffer (if not out of space) and read next one 437 */ 438 static int nextc (RN *rn) { 439 if (l_unlikely(rn->n >= L_MAXLENNUM)) { /* buffer overflow? */ 440 rn->buff[0] = '\0'; /* invalidate result */ 441 return 0; /* fail */ 442 } 443 else { 444 rn->buff[rn->n++] = rn->c; /* save current char */ 445 rn->c = l_getc(rn->f); /* read next one */ 446 return 1; 447 } 448 } 449 450 451 /* 452 ** Accept current char if it is in 'set' (of size 2) 453 */ 454 static int test2 (RN *rn, const char *set) { 455 if (rn->c == set[0] || rn->c == set[1]) 456 return nextc(rn); 457 else return 0; 458 } 459 460 461 /* 462 ** Read a sequence of (hex)digits 463 */ 464 static int readdigits (RN *rn, int hex) { 465 int count = 0; 466 while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn)) 467 count++; 468 return count; 469 } 470 471 472 /* 473 ** Read a number: first reads a valid prefix of a numeral into a buffer. 474 ** Then it calls 'lua_stringtonumber' to check whether the format is 475 ** correct and to convert it to a Lua number. 476 */ 477 static int read_number (lua_State *L, FILE *f) { 478 RN rn; 479 int count = 0; 480 int hex = 0; 481 char decp[2]; 482 rn.f = f; rn.n = 0; 483 decp[0] = lua_getlocaledecpoint(); /* get decimal point from locale */ 484 decp[1] = '.'; /* always accept a dot */ 485 l_lockfile(rn.f); 486 do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */ 487 test2(&rn, "-+"); /* optional sign */ 488 if (test2(&rn, "00")) { 489 if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */ 490 else count = 1; /* count initial '0' as a valid digit */ 491 } 492 count += readdigits(&rn, hex); /* integral part */ 493 if (test2(&rn, decp)) /* decimal point? */ 494 count += readdigits(&rn, hex); /* fractional part */ 495 if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */ 496 test2(&rn, "-+"); /* exponent sign */ 497 readdigits(&rn, 0); /* exponent digits */ 498 } 499 ungetc(rn.c, rn.f); /* unread look-ahead char */ 500 l_unlockfile(rn.f); 501 rn.buff[rn.n] = '\0'; /* finish string */ 502 if (l_likely(lua_stringtonumber(L, rn.buff))) 503 return 1; /* ok, it is a valid number */ 504 else { /* invalid format */ 505 lua_pushnil(L); /* "result" to be removed */ 506 return 0; /* read fails */ 507 } 508 } 509 510 511 static int test_eof (lua_State *L, FILE *f) { 512 int c = getc(f); 513 ungetc(c, f); /* no-op when c == EOF */ 514 lua_pushliteral(L, ""); 515 return (c != EOF); 516 } 517 518 519 static int read_line (lua_State *L, FILE *f, int chop) { 520 luaL_Buffer b; 521 int c; 522 luaL_buffinit(L, &b); 523 do { /* may need to read several chunks to get whole line */ 524 char *buff = luaL_prepbuffer(&b); /* preallocate buffer space */ 525 int i = 0; 526 l_lockfile(f); /* no memory errors can happen inside the lock */ 527 while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n') 528 buff[i++] = c; /* read up to end of line or buffer limit */ 529 l_unlockfile(f); 530 luaL_addsize(&b, i); 531 } while (c != EOF && c != '\n'); /* repeat until end of line */ 532 if (!chop && c == '\n') /* want a newline and have one? */ 533 luaL_addchar(&b, c); /* add ending newline to result */ 534 luaL_pushresult(&b); /* close buffer */ 535 /* return ok if read something (either a newline or something else) */ 536 return (c == '\n' || lua_rawlen(L, -1) > 0); 537 } 538 539 540 static void read_all (lua_State *L, FILE *f) { 541 size_t nr; 542 luaL_Buffer b; 543 luaL_buffinit(L, &b); 544 do { /* read file in chunks of LUAL_BUFFERSIZE bytes */ 545 char *p = luaL_prepbuffer(&b); 546 nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f); 547 luaL_addsize(&b, nr); 548 } while (nr == LUAL_BUFFERSIZE); 549 luaL_pushresult(&b); /* close buffer */ 550 } 551 552 553 static int read_chars (lua_State *L, FILE *f, size_t n) { 554 size_t nr; /* number of chars actually read */ 555 char *p; 556 luaL_Buffer b; 557 luaL_buffinit(L, &b); 558 p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */ 559 nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */ 560 luaL_addsize(&b, nr); 561 luaL_pushresult(&b); /* close buffer */ 562 return (nr > 0); /* true iff read something */ 563 } 564 565 566 static int g_read (lua_State *L, FILE *f, int first) { 567 int nargs = lua_gettop(L) - 1; 568 int n, success; 569 clearerr(f); 570 if (nargs == 0) { /* no arguments? */ 571 success = read_line(L, f, 1); 572 n = first + 1; /* to return 1 result */ 573 } 574 else { 575 /* ensure stack space for all results and for auxlib's buffer */ 576 luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); 577 success = 1; 578 for (n = first; nargs-- && success; n++) { 579 if (lua_type(L, n) == LUA_TNUMBER) { 580 size_t l = (size_t)luaL_checkinteger(L, n); 581 success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); 582 } 583 else { 584 const char *p = luaL_checkstring(L, n); 585 if (*p == '*') p++; /* skip optional '*' (for compatibility) */ 586 switch (*p) { 587 case 'n': /* number */ 588 success = read_number(L, f); 589 break; 590 case 'l': /* line */ 591 success = read_line(L, f, 1); 592 break; 593 case 'L': /* line with end-of-line */ 594 success = read_line(L, f, 0); 595 break; 596 case 'a': /* file */ 597 read_all(L, f); /* read entire file */ 598 success = 1; /* always success */ 599 break; 600 default: 601 return luaL_argerror(L, n, "invalid format"); 602 } 603 } 604 } 605 } 606 if (ferror(f)) 607 return luaL_fileresult(L, 0, NULL); 608 if (!success) { 609 lua_pop(L, 1); /* remove last result */ 610 luaL_pushfail(L); /* push nil instead */ 611 } 612 return n - first; 613 } 614 615 616 static int io_read (lua_State *L) { 617 return g_read(L, getiofile(L, IO_INPUT), 1); 618 } 619 620 621 static int f_read (lua_State *L) { 622 return g_read(L, tofile(L), 2); 623 } 624 625 626 /* 627 ** Iteration function for 'lines'. 628 */ 629 static int io_readline (lua_State *L) { 630 LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1)); 631 int i; 632 int n = (int)lua_tointeger(L, lua_upvalueindex(2)); 633 if (isclosed(p)) /* file is already closed? */ 634 return luaL_error(L, "file is already closed"); 635 lua_settop(L , 1); 636 luaL_checkstack(L, n, "too many arguments"); 637 for (i = 1; i <= n; i++) /* push arguments to 'g_read' */ 638 lua_pushvalue(L, lua_upvalueindex(3 + i)); 639 n = g_read(L, p->f, 2); /* 'n' is number of results */ 640 lua_assert(n > 0); /* should return at least a nil */ 641 if (lua_toboolean(L, -n)) /* read at least one value? */ 642 return n; /* return them */ 643 else { /* first result is false: EOF or error */ 644 if (n > 1) { /* is there error information? */ 645 /* 2nd result is error message */ 646 return luaL_error(L, "%s", lua_tostring(L, -n + 1)); 647 } 648 if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */ 649 lua_settop(L, 0); /* clear stack */ 650 lua_pushvalue(L, lua_upvalueindex(1)); /* push file at index 1 */ 651 aux_close(L); /* close it */ 652 } 653 return 0; 654 } 655 } 656 657 /* }====================================================== */ 658 659 660 static int g_write (lua_State *L, FILE *f, int arg) { 661 int nargs = lua_gettop(L) - arg; 662 int status = 1; 663 for (; nargs--; arg++) { 664 if (lua_type(L, arg) == LUA_TNUMBER) { 665 /* optimization: could be done exactly as for strings */ 666 int len = lua_isinteger(L, arg) 667 ? fprintf(f, LUA_INTEGER_FMT, 668 (LUAI_UACINT)lua_tointeger(L, arg)) 669 : fprintf(f, LUA_NUMBER_FMT, 670 (LUAI_UACNUMBER)lua_tonumber(L, arg)); 671 status = status && (len > 0); 672 } 673 else { 674 size_t l; 675 const char *s = luaL_checklstring(L, arg, &l); 676 status = status && (fwrite(s, sizeof(char), l, f) == l); 677 } 678 } 679 if (l_likely(status)) 680 return 1; /* file handle already on stack top */ 681 else return luaL_fileresult(L, status, NULL); 682 } 683 684 685 static int io_write (lua_State *L) { 686 return g_write(L, getiofile(L, IO_OUTPUT), 1); 687 } 688 689 690 static int f_write (lua_State *L) { 691 FILE *f = tofile(L); 692 lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */ 693 return g_write(L, f, 2); 694 } 695 696 697 static int f_seek (lua_State *L) { 698 static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; 699 static const char *const modenames[] = {"set", "cur", "end", NULL}; 700 FILE *f = tofile(L); 701 int op = luaL_checkoption(L, 2, "cur", modenames); 702 lua_Integer p3 = luaL_optinteger(L, 3, 0); 703 l_seeknum offset = (l_seeknum)p3; 704 luaL_argcheck(L, (lua_Integer)offset == p3, 3, 705 "not an integer in proper range"); 706 op = l_fseek(f, offset, mode[op]); 707 if (l_unlikely(op)) 708 return luaL_fileresult(L, 0, NULL); /* error */ 709 else { 710 lua_pushinteger(L, (lua_Integer)l_ftell(f)); 711 return 1; 712 } 713 } 714 715 716 static int f_setvbuf (lua_State *L) { 717 static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; 718 static const char *const modenames[] = {"no", "full", "line", NULL}; 719 FILE *f = tofile(L); 720 int op = luaL_checkoption(L, 2, NULL, modenames); 721 lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); 722 int res = setvbuf(f, NULL, mode[op], (size_t)sz); 723 return luaL_fileresult(L, res == 0, NULL); 724 } 725 726 727 728 static int io_flush (lua_State *L) { 729 return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); 730 } 731 732 733 static int f_flush (lua_State *L) { 734 return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL); 735 } 736 737 738 /* 739 ** functions for 'io' library 740 */ 741 static const luaL_Reg iolib[] = { 742 {"close", io_close}, 743 {"flush", io_flush}, 744 {"input", io_input}, 745 {"lines", io_lines}, 746 {"open", io_open}, 747 {"output", io_output}, 748 {"popen", io_popen}, 749 {"read", io_read}, 750 {"tmpfile", io_tmpfile}, 751 {"type", io_type}, 752 {"write", io_write}, 753 {NULL, NULL} 754 }; 755 756 757 /* 758 ** methods for file handles 759 */ 760 static const luaL_Reg meth[] = { 761 {"read", f_read}, 762 {"write", f_write}, 763 {"lines", f_lines}, 764 {"flush", f_flush}, 765 {"seek", f_seek}, 766 {"close", f_close}, 767 {"setvbuf", f_setvbuf}, 768 {NULL, NULL} 769 }; 770 771 772 /* 773 ** metamethods for file handles 774 */ 775 static const luaL_Reg metameth[] = { 776 {"__index", NULL}, /* place holder */ 777 {"__gc", f_gc}, 778 {"__close", f_gc}, 779 {"__tostring", f_tostring}, 780 {NULL, NULL} 781 }; 782 783 784 static void createmeta (lua_State *L) { 785 luaL_newmetatable(L, LUA_FILEHANDLE); /* metatable for file handles */ 786 luaL_setfuncs(L, metameth, 0); /* add metamethods to new metatable */ 787 luaL_newlibtable(L, meth); /* create method table */ 788 luaL_setfuncs(L, meth, 0); /* add file methods to method table */ 789 lua_setfield(L, -2, "__index"); /* metatable.__index = method table */ 790 lua_pop(L, 1); /* pop metatable */ 791 } 792 793 794 /* 795 ** function to (not) close the standard files stdin, stdout, and stderr 796 */ 797 static int io_noclose (lua_State *L) { 798 LStream *p = tolstream(L); 799 p->closef = &io_noclose; /* keep file opened */ 800 luaL_pushfail(L); 801 lua_pushliteral(L, "cannot close standard file"); 802 return 2; 803 } 804 805 806 static void createstdfile (lua_State *L, FILE *f, const char *k, 807 const char *fname) { 808 LStream *p = newprefile(L); 809 p->f = f; 810 p->closef = &io_noclose; 811 if (k != NULL) { 812 lua_pushvalue(L, -1); 813 lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */ 814 } 815 lua_setfield(L, -2, fname); /* add file to module */ 816 } 817 818 819 LUAMOD_API int luaopen_io (lua_State *L) { 820 luaL_newlib(L, iolib); /* new module */ 821 createmeta(L); 822 /* create (and set) default files */ 823 createstdfile(L, stdin, IO_INPUT, "stdin"); 824 createstdfile(L, stdout, IO_OUTPUT, "stdout"); 825 createstdfile(L, stderr, NULL, "stderr"); 826 return 1; 827 } 828 829