nanocoat/lib/3rdparty/lua/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   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