client/deps/liblua/liolib.c

   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     } else { /* open a new file */
 398         const char *filename = luaL_checkstring(L, 1);
 399         opencheck(L, filename, "r");
 400         lua_replace(L, 1);  /* put file at index 1 */
 401         toclose = 1;  /* close it after iteration */
 402     }
 403     aux_lines(L, toclose);  /* push iteration function */
 404     if (toclose) {
 405         lua_pushnil(L);  /* state */
 406         lua_pushnil(L);  /* control */
 407         lua_pushvalue(L, 1);  /* file is the to-be-closed variable (4th result) */
 408         return 4;
 409     } else
 410         return 1;
 411 }
 412
 413
 414 /*
 415 ** {======================================================
 416 ** READ
 417 ** =======================================================
 418 */
 419
 420
 421 /* maximum length of a numeral */
 422 #if !defined (L_MAXLENNUM)
 423 #define L_MAXLENNUM     200
 424 #endif
 425
 426
 427 /* auxiliary structure used by 'read_number' */
 428 typedef struct {
 429     FILE *f;  /* file being read */
 430     int c;  /* current character (look ahead) */
 431     int n;  /* number of elements in buffer 'buff' */
 432     char buff[L_MAXLENNUM + 1];  /* +1 for ending '\0' */
 433 } RN;
 434
 435
 436 /*
 437 ** Add current char to buffer (if not out of space) and read next one
 438 */
 439 static int nextc(RN *rn) {
 440     if (l_unlikely(rn->n >= L_MAXLENNUM)) {  /* buffer overflow? */
 441         rn->buff[0] = '\0';  /* invalidate result */
 442         return 0;  /* fail */
 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;
 483     rn.n = 0;
 484     decp[0] = lua_getlocaledecpoint();  /* get decimal point from locale */
 485     decp[1] = '.';  /* always accept a dot */
 486     l_lockfile(rn.f);
 487     do { rn.c = l_getc(rn.f); }
 488     while (isspace(rn.c));    /* skip spaces */
 489     test2(&rn, "-+");  /* optional sign */
 490     if (test2(&rn, "00")) {
 491         if (test2(&rn, "xX")) hex = 1;  /* numeral is hexadecimal */
 492         else count = 1;  /* count initial '0' as a valid digit */
 493     }
 494     count += readdigits(&rn, hex);  /* integral part */
 495     if (test2(&rn, decp))  /* decimal point? */
 496         count += readdigits(&rn, hex);  /* fractional part */
 497     if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) {  /* exponent mark? */
 498         test2(&rn, "-+");  /* exponent sign */
 499         readdigits(&rn, 0);  /* exponent digits */
 500     }
 501     ungetc(rn.c, rn.f);  /* unread look-ahead char */
 502     l_unlockfile(rn.f);
 503     rn.buff[rn.n] = '\0';  /* finish string */
 504     if (l_likely(lua_stringtonumber(L, rn.buff)))
 505         return 1;  /* ok, it is a valid number */
 506     else {  /* invalid format */
 507         lua_pushnil(L);  /* "result" to be removed */
 508         return 0;  /* read fails */
 509     }
 510 }
 511
 512
 513 static int test_eof(lua_State *L, FILE *f) {
 514     int c = getc(f);
 515     ungetc(c, f);  /* no-op when c == EOF */
 516     lua_pushliteral(L, "");
 517     return (c != EOF);
 518 }
 519
 520
 521 static int read_line(lua_State *L, FILE *f, int chop) {
 522     luaL_Buffer b;
 523     int c;
 524     luaL_buffinit(L, &b);
 525     do {  /* may need to read several chunks to get whole line */
 526         char *buff = luaL_prepbuffer(&b);  /* preallocate buffer space */
 527         int i = 0;
 528         l_lockfile(f);  /* no memory errors can happen inside the lock */
 529         while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
 530             buff[i++] = c;  /* read up to end of line or buffer limit */
 531         l_unlockfile(f);
 532         luaL_addsize(&b, i);
 533     } while (c != EOF && c != '\n');  /* repeat until end of line */
 534     if (!chop && c == '\n')  /* want a newline and have one? */
 535         luaL_addchar(&b, c);  /* add ending newline to result */
 536     luaL_pushresult(&b);  /* close buffer */
 537     /* return ok if read something (either a newline or something else) */
 538     return (c == '\n' || lua_rawlen(L, -1) > 0);
 539 }
 540
 541
 542 static void read_all(lua_State *L, FILE *f) {
 543     size_t nr;
 544     luaL_Buffer b;
 545     luaL_buffinit(L, &b);
 546     do {  /* read file in chunks of LUAL_BUFFERSIZE bytes */
 547         char *p = luaL_prepbuffer(&b);
 548         nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f);
 549         luaL_addsize(&b, nr);
 550     } while (nr == LUAL_BUFFERSIZE);
 551     luaL_pushresult(&b);  /* close buffer */
 552 }
 553
 554
 555 static int read_chars(lua_State *L, FILE *f, size_t n) {
 556     size_t nr;  /* number of chars actually read */
 557     char *p;
 558     luaL_Buffer b;
 559     luaL_buffinit(L, &b);
 560     p = luaL_prepbuffsize(&b, n);  /* prepare buffer to read whole block */
 561     nr = fread(p, sizeof(char), n, f);  /* try to read 'n' chars */
 562     luaL_addsize(&b, nr);
 563     luaL_pushresult(&b);  /* close buffer */
 564     return (nr > 0);  /* true iff read something */
 565 }
 566
 567
 568 static int g_read(lua_State *L, FILE *f, int first) {
 569     int nargs = lua_gettop(L) - 1;
 570     int n, success;
 571     clearerr(f);
 572     errno = 0;
 573     if (nargs == 0) {  /* no arguments? */
 574         success = read_line(L, f, 1);
 575         n = first + 1;  /* to return 1 result */
 576     } else {
 577         /* ensure stack space for all results and for auxlib's buffer */
 578         luaL_checkstack(L, nargs + LUA_MINSTACK, "too many arguments");
 579         success = 1;
 580         for (n = first; nargs-- && success; n++) {
 581             if (lua_type(L, n) == LUA_TNUMBER) {
 582                 size_t l = (size_t)luaL_checkinteger(L, n);
 583                 success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
 584             } else {
 585                 const char *p = luaL_checkstring(L, n);
 586                 if (*p == '*') p++;  /* skip optional '*' (for compatibility) */
 587                 switch (*p) {
 588                     case 'n':  /* number */
 589                         success = read_number(L, f);
 590                         break;
 591                     case 'l':  /* line */
 592                         success = read_line(L, f, 1);
 593                         break;
 594                     case 'L':  /* line with end-of-line */
 595                         success = read_line(L, f, 0);
 596                         break;
 597                     case 'a':  /* file */
 598                         read_all(L, f);  /* read entire file */
 599                         success = 1; /* always success */
 600                         break;
 601                     default:
 602                         return luaL_argerror(L, n, "invalid format");
 603                 }
 604             }
 605         }
 606     }
 607     if (ferror(f))
 608         return luaL_fileresult(L, 0, NULL);
 609     if (!success) {
 610         lua_pop(L, 1);  /* remove last result */
 611         luaL_pushfail(L);  /* push nil instead */
 612     }
 613     return n - first;
 614 }
 615
 616
 617 static int io_read(lua_State *L) {
 618     return g_read(L, getiofile(L, IO_INPUT), 1);
 619 }
 620
 621
 622 static int f_read(lua_State *L) {
 623     return g_read(L, tofile(L), 2);
 624 }
 625
 626
 627 /*
 628 ** Iteration function for 'lines'.
 629 */
 630 static int io_readline(lua_State *L) {
 631     LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
 632     int i;
 633     int n = (int)lua_tointeger(L, lua_upvalueindex(2));
 634     if (isclosed(p))  /* file is already closed? */
 635         return luaL_error(L, "file is already closed");
 636     lua_settop(L, 1);
 637     luaL_checkstack(L, n, "too many arguments");
 638     for (i = 1; i <= n; i++)  /* push arguments to 'g_read' */
 639         lua_pushvalue(L, lua_upvalueindex(3 + i));
 640     n = g_read(L, p->f, 2);  /* 'n' is number of results */
 641     lua_assert(n > 0);  /* should return at least a nil */
 642     if (lua_toboolean(L, -n))  /* read at least one value? */
 643         return n;  /* return them */
 644     else {  /* first result is false: EOF or error */
 645         if (n > 1) {  /* is there error information? */
 646             /* 2nd result is error message */
 647             return luaL_error(L, "%s", lua_tostring(L, -n + 1));
 648         }
 649         if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */
 650             lua_settop(L, 0);  /* clear stack */
 651             lua_pushvalue(L, lua_upvalueindex(1));  /* push file at index 1 */
 652             aux_close(L);  /* close it */
 653         }
 654         return 0;
 655     }
 656 }
 657
 658 /* }====================================================== */
 659
 660
 661 static int g_write(lua_State *L, FILE *f, int arg) {
 662     int nargs = lua_gettop(L) - arg;
 663     int status = 1;
 664     errno = 0;
 665     for (; nargs--; arg++) {
 666         if (lua_type(L, arg) == LUA_TNUMBER) {
 667             /* optimization: could be done exactly as for strings */
 668             int len = lua_isinteger(L, arg)
 669                       ? fprintf(f, LUA_INTEGER_FMT,
 670                                 (LUAI_UACINT)lua_tointeger(L, arg))
 671                       : fprintf(f, LUA_NUMBER_FMT,
 672                                 (LUAI_UACNUMBER)lua_tonumber(L, arg));
 673             status = status && (len > 0);
 674         } else {
 675             size_t l;
 676             const char *s = luaL_checklstring(L, arg, &l);
 677             status = status && (fwrite(s, sizeof(char), l, f) == l);
 678         }
 679     }
 680     if (l_likely(status))
 681         return 1;  /* file handle already on stack top */
 682     else
 683         return luaL_fileresult(L, status, NULL);
 684 }
 685
 686
 687 static int io_write(lua_State *L) {
 688     return g_write(L, getiofile(L, IO_OUTPUT), 1);
 689 }
 690
 691
 692 static int f_write(lua_State *L) {
 693     FILE *f = tofile(L);
 694     lua_pushvalue(L, 1);  /* push file at the stack top (to be returned) */
 695     return g_write(L, f, 2);
 696 }
 697
 698
 699 static int f_seek(lua_State *L) {
 700     static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
 701     static const char *const modenames[] = {"set", "cur", "end", NULL};
 702     FILE *f = tofile(L);
 703     int op = luaL_checkoption(L, 2, "cur", modenames);
 704     lua_Integer p3 = luaL_optinteger(L, 3, 0);
 705     l_seeknum offset = (l_seeknum)p3;
 706     luaL_argcheck(L, (lua_Integer)offset == p3, 3,
 707                   "not an integer in proper range");
 708     errno = 0;
 709     op = l_fseek(f, offset, mode[op]);
 710     if (l_unlikely(op))
 711         return luaL_fileresult(L, 0, NULL);  /* error */
 712     else {
 713         lua_pushinteger(L, (lua_Integer)l_ftell(f));
 714         return 1;
 715     }
 716 }
 717
 718
 719 static int f_setvbuf(lua_State *L) {
 720     static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
 721     static const char *const modenames[] = {"no", "full", "line", NULL};
 722     FILE *f = tofile(L);
 723     int op = luaL_checkoption(L, 2, NULL, modenames);
 724     lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
 725     int res;
 726     errno = 0;
 727     res = setvbuf(f, NULL, mode[op], (size_t)sz);
 728     return luaL_fileresult(L, res == 0, NULL);
 729 }
 730
 731
 732
 733 static int io_flush(lua_State *L) {
 734     FILE *f = getiofile(L, IO_OUTPUT);
 735     errno = 0;
 736     return luaL_fileresult(L, fflush(f) == 0, NULL);
 737 }
 738
 739
 740 static int f_flush(lua_State *L) {
 741     FILE *f = tofile(L);
 742     errno = 0;
 743     return luaL_fileresult(L, fflush(f) == 0, NULL);
 744 }
 745
 746
 747 /*
 748 ** functions for 'io' library
 749 */
 750 static const luaL_Reg iolib[] = {
 751     {"close", io_close},
 752     {"flush", io_flush},
 753     {"input", io_input},
 754     {"lines", io_lines},
 755     {"open", io_open},
 756     {"output", io_output},
 757     {"popen", io_popen},
 758     {"read", io_read},
 759     {"tmpfile", io_tmpfile},
 760     {"type", io_type},
 761     {"write", io_write},
 762     {NULL, NULL}
 763 };
 764
 765
 766 /*
 767 ** methods for file handles
 768 */
 769 static const luaL_Reg meth[] = {
 770     {"read", f_read},
 771     {"write", f_write},
 772     {"lines", f_lines},
 773     {"flush", f_flush},
 774     {"seek", f_seek},
 775     {"close", f_close},
 776     {"setvbuf", f_setvbuf},
 777     {NULL, NULL}
 778 };
 779
 780
 781 /*
 782 ** metamethods for file handles
 783 */
 784 static const luaL_Reg metameth[] = {
 785     {"__index", NULL},  /* placeholder */
 786     {"__gc", f_gc},
 787     {"__close", f_gc},
 788     {"__tostring", f_tostring},
 789     {NULL, NULL}
 790 };
 791
 792
 793 static void createmeta(lua_State *L) {
 794     luaL_newmetatable(L, LUA_FILEHANDLE);  /* metatable for file handles */
 795     luaL_setfuncs(L, metameth, 0);  /* add metamethods to new metatable */
 796     luaL_newlibtable(L, meth);  /* create method table */
 797     luaL_setfuncs(L, meth, 0);  /* add file methods to method table */
 798     lua_setfield(L, -2, "__index");  /* metatable.__index = method table */
 799     lua_pop(L, 1);  /* pop metatable */
 800 }
 801
 802
 803 /*
 804 ** function to (not) close the standard files stdin, stdout, and stderr
 805 */
 806 static int io_noclose(lua_State *L) {
 807     LStream *p = tolstream(L);
 808     p->closef = &io_noclose;  /* keep file opened */
 809     luaL_pushfail(L);
 810     lua_pushliteral(L, "cannot close standard file");
 811     return 2;
 812 }
 813
 814
 815 static void createstdfile(lua_State *L, FILE *f, const char *k,
 816                           const char *fname) {
 817     LStream *p = newprefile(L);
 818     p->f = f;
 819     p->closef = &io_noclose;
 820     if (k != NULL) {
 821         lua_pushvalue(L, -1);
 822         lua_setfield(L, LUA_REGISTRYINDEX, k);  /* add file to registry */
 823     }
 824     lua_setfield(L, -2, fname);  /* add file to module */
 825 }
 826
 827
 828 LUAMOD_API int luaopen_io(lua_State *L) {
 829     luaL_newlib(L, iolib);  /* new module */
 830     createmeta(L);
 831     /* create (and set) default files */
 832     createstdfile(L, stdin, IO_INPUT, "stdin");
 833     createstdfile(L, stdout, IO_OUTPUT, "stdout");
 834     createstdfile(L, stderr, NULL, "stderr");
 835     return 1;
 836 }
 837