com32/lua/src/liolib.c

   1 /*
   2 ** $Id: liolib.c,v 2.73.1.4 2010/05/14 15:33:51 roberto Exp $
   3 ** Standard I/O (and system) library
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <errno.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 #define liolib_c
  14 #define LUA_LIB
  15
  16 #include "lua.h"
  17
  18 #include "lauxlib.h"
  19 #include "lualib.h"
  20
  21 #ifdef SYSLINUX
  22   #define NO_TMP_FILE    1
  23   #define NO_READ_NUMBER 1
  24   #define NO_TEST_EOF    1
  25   #define NO_CLEAR_ERR   1
  26   #define NO_F_SEEK      1
  27   #define NO_F_SETVBUF   1
  28 #endif
  29
  30 #define IO_INPUT        1
  31 #define IO_OUTPUT       2
  32
  33 static const char *const fnames[] = {"input", "output"};
  34
  35
  36 static int pushresult (lua_State *L, int i, const char *filename) {
  37   int en = errno;  /* calls to Lua API may change this value */
  38   if (i) {
  39     lua_pushboolean(L, 1);
  40     return 1;
  41   }
  42   else {
  43     lua_pushnil(L);
  44     if (filename)
  45       lua_pushfstring(L, "%s: %s", filename, strerror(en));
  46     else
  47       lua_pushfstring(L, "%s", strerror(en));
  48     lua_pushinteger(L, en);
  49     return 3;
  50   }
  51 }
  52
  53
  54 static void fileerror (lua_State *L, int arg, const char *filename) {
  55   lua_pushfstring(L, "%s: %s", filename, strerror(errno));
  56   luaL_argerror(L, arg, lua_tostring(L, -1));
  57 }
  58
  59
  60 #define tofilep(L)      ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
  61
  62
  63 static int io_type (lua_State *L) {
  64   void *ud;
  65   luaL_checkany(L, 1);
  66   ud = lua_touserdata(L, 1);
  67   lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
  68   if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
  69     lua_pushnil(L);  /* not a file */
  70   else if (*((FILE **)ud) == NULL)
  71     lua_pushliteral(L, "closed file");
  72   else
  73     lua_pushliteral(L, "file");
  74   return 1;
  75 }
  76
  77
  78 static FILE *tofile (lua_State *L) {
  79   FILE **f = tofilep(L);
  80   if (*f == NULL)
  81     luaL_error(L, "attempt to use a closed file");
  82   return *f;
  83 }
  84
  85
  86
  87 /*
  88 ** When creating file handles, always creates a `closed' file handle
  89 ** before opening the actual file; so, if there is a memory error, the
  90 ** file is not left opened.
  91 */
  92 static FILE **newfile (lua_State *L) {
  93   FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
  94   *pf = NULL;  /* file handle is currently `closed' */
  95   luaL_getmetatable(L, LUA_FILEHANDLE);
  96   lua_setmetatable(L, -2);
  97   return pf;
  98 }
  99
 100
 101 /*
 102 ** function to (not) close the standard files stdin, stdout, and stderr
 103 */
 104 static int io_noclose (lua_State *L) {
 105   lua_pushnil(L);
 106   lua_pushliteral(L, "cannot close standard file");
 107   return 2;
 108 }
 109
 110
 111 /*
 112 ** function to close 'popen' files
 113 */
 114 static int io_pclose (lua_State *L) {
 115   FILE **p = tofilep(L);
 116   int ok = lua_pclose(L, *p);
 117   *p = NULL;
 118   return pushresult(L, ok, NULL);
 119 }
 120
 121
 122 /*
 123 ** function to close regular files
 124 */
 125 static int io_fclose (lua_State *L) {
 126   FILE **p = tofilep(L);
 127   int ok = (fclose(*p) == 0);
 128   *p = NULL;
 129   return pushresult(L, ok, NULL);
 130 }
 131
 132
 133 static int aux_close (lua_State *L) {
 134   lua_getfenv(L, 1);
 135   lua_getfield(L, -1, "__close");
 136   return (lua_tocfunction(L, -1))(L);
 137 }
 138
 139
 140 static int io_close (lua_State *L) {
 141   if (lua_isnone(L, 1))
 142     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
 143   tofile(L);  /* make sure argument is a file */
 144   return aux_close(L);
 145 }
 146
 147
 148 static int io_gc (lua_State *L) {
 149   FILE *f = *tofilep(L);
 150   /* ignore closed files */
 151   if (f != NULL)
 152     aux_close(L);
 153   return 0;
 154 }
 155
 156
 157 static int io_tostring (lua_State *L) {
 158   FILE *f = *tofilep(L);
 159   if (f == NULL)
 160     lua_pushliteral(L, "file (closed)");
 161   else
 162     lua_pushfstring(L, "file (%p)", f);
 163   return 1;
 164 }
 165
 166
 167 static int io_open (lua_State *L) {
 168   const char *filename = luaL_checkstring(L, 1);
 169   const char *mode = luaL_optstring(L, 2, "r");
 170   FILE **pf = newfile(L);
 171   *pf = fopen(filename, mode);
 172   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 173 }
 174
 175
 176 /*
 177 ** this function has a separated environment, which defines the
 178 ** correct __close for 'popen' files
 179 */
 180 static int io_popen (lua_State *L) {
 181   const char *filename = luaL_checkstring(L, 1);
 182   const char *mode = luaL_optstring(L, 2, "r");
 183   FILE **pf = newfile(L);
 184   *pf = lua_popen(L, filename, mode);
 185   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 186 }
 187
 188
 189 #ifndef NO_TMP_FILE
 190 static int io_tmpfile (lua_State *L) {
 191   FILE **pf = newfile(L);
 192   *pf = tmpfile();
 193   return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
 194 }
 195 #endif
 196
 197
 198 static FILE *getiofile (lua_State *L, int findex) {
 199   FILE *f;
 200   lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
 201   f = *(FILE **)lua_touserdata(L, -1);
 202   if (f == NULL)
 203     luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
 204   return f;
 205 }
 206
 207
 208 static int g_iofile (lua_State *L, int f, const char *mode) {
 209   if (!lua_isnoneornil(L, 1)) {
 210     const char *filename = lua_tostring(L, 1);
 211     if (filename) {
 212       FILE **pf = newfile(L);
 213       *pf = fopen(filename, mode);
 214       if (*pf == NULL)
 215         fileerror(L, 1, filename);
 216     }
 217     else {
 218       tofile(L);  /* check that it's a valid file handle */
 219       lua_pushvalue(L, 1);
 220     }
 221     lua_rawseti(L, LUA_ENVIRONINDEX, f);
 222   }
 223   /* return current value */
 224   lua_rawgeti(L, LUA_ENVIRONINDEX, f);
 225   return 1;
 226 }
 227
 228
 229 static int io_input (lua_State *L) {
 230   return g_iofile(L, IO_INPUT, "r");
 231 }
 232
 233
 234 static int io_output (lua_State *L) {
 235   return g_iofile(L, IO_OUTPUT, "w");
 236 }
 237
 238
 239 static int io_readline (lua_State *L);
 240
 241
 242 static void aux_lines (lua_State *L, int idx, int toclose) {
 243   lua_pushvalue(L, idx);
 244   lua_pushboolean(L, toclose);  /* close/not close file when finished */
 245   lua_pushcclosure(L, io_readline, 2);
 246 }
 247
 248
 249 static int f_lines (lua_State *L) {
 250   tofile(L);  /* check that it's a valid file handle */
 251   aux_lines(L, 1, 0);
 252   return 1;
 253 }
 254
 255
 256 static int io_lines (lua_State *L) {
 257   if (lua_isnoneornil(L, 1)) {  /* no arguments? */
 258     /* will iterate over default input */
 259     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
 260     return f_lines(L);
 261   }
 262   else {
 263     const char *filename = luaL_checkstring(L, 1);
 264     FILE **pf = newfile(L);
 265     *pf = fopen(filename, "r");
 266     if (*pf == NULL)
 267       fileerror(L, 1, filename);
 268     aux_lines(L, lua_gettop(L), 1);
 269     return 1;
 270   }
 271 }
 272
 273
 274 /*
 275 ** {======================================================
 276 ** READ
 277 ** =======================================================
 278 */
 279
 280 #ifndef NO_READ_NUMBER /* No fscanf() and thus no read_number() */
 281 static int read_number (lua_State *L, FILE *f) {
 282   lua_Number d;
 283   if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
 284     lua_pushnumber(L, d);
 285     return 1;
 286   }
 287   else {
 288     lua_pushnil(L);  /* "result" to be removed */
 289     return 0;  /* read fails */
 290   }
 291 }
 292 #endif
 293
 294 #ifndef NO_TEST_EOF  /* no buffering -> no ungetc() -> no EOF test */
 295 static int test_eof (lua_State *L, FILE *f) {
 296   int c = getc(f);
 297   ungetc(c, f);
 298   lua_pushlstring(L, NULL, 0);
 299   return (c != EOF);
 300 }
 301 #endif
 302
 303
 304 static int read_line (lua_State *L, FILE *f) {
 305   luaL_Buffer b;
 306   luaL_buffinit(L, &b);
 307   for (;;) {
 308     size_t l;
 309     char *p = luaL_prepbuffer(&b);
 310     if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) {  /* eof? */
 311       luaL_pushresult(&b);  /* close buffer */
 312       return (lua_objlen(L, -1) > 0);  /* check whether read something */
 313     }
 314     l = strlen(p);
 315     if (l == 0 || p[l-1] != '\n')
 316       luaL_addsize(&b, l);
 317     else {
 318       luaL_addsize(&b, l - 1);  /* do not include `eol' */
 319       luaL_pushresult(&b);  /* close buffer */
 320       return 1;  /* read at least an `eol' */
 321     }
 322   }
 323 }
 324
 325 static int read_chars (lua_State *L, FILE *f, size_t n) {
 326   size_t rlen;  /* how much to read */
 327   size_t nr;  /* number of chars actually read */
 328   luaL_Buffer b;
 329   luaL_buffinit(L, &b);
 330   rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
 331   do {
 332     char *p = luaL_prepbuffer(&b);
 333     if (rlen > n) rlen = n;  /* cannot read more than asked */
 334     nr = fread(p, sizeof(char), rlen, f);
 335     luaL_addsize(&b, nr);
 336     n -= nr;  /* still have to read `n' chars */
 337   } while (n > 0 && nr == rlen);  /* until end of count or eof */
 338   luaL_pushresult(&b);  /* close buffer */
 339   return (n == 0 || lua_objlen(L, -1) > 0);
 340 }
 341
 342 static int g_read (lua_State *L, FILE *f, int first) {
 343   int nargs = lua_gettop(L) - 1;
 344   int success;
 345   int n;
 346 #ifndef NO_CLEAR_ERR
 347   clearerr(f);
 348 #endif
 349   if (nargs == 0) {  /* no arguments? */
 350     success = read_line(L, f);
 351     n = first+1;  /* to return 1 result */
 352   }
 353   else {  /* ensure stack space for all results and for auxlib's buffer */
 354     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
 355     success = 1;
 356     for (n = first; nargs-- && success; n++) {
 357       if (lua_type(L, n) == LUA_TNUMBER) {
 358         size_t l = (size_t)lua_tointeger(L, n);
 359 #ifndef NO_TEST_EOF
 360         success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
 361 #else  /* we don't have test_eof defined */
 362         success = (l == 0) ? 1 : read_chars(L, f, l);
 363 #endif
 364       }
 365       else {
 366         const char *p = lua_tostring(L, n);
 367         luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
 368         switch (p[1]) {
 369           case 'n':  /* number */
 370 #ifndef NO_READ_NUMBER
 371             success = read_number(L, f);
 372 #else
 373             return luaL_argerror(L, n, "\"*number\" not supported");
 374 #endif
 375             break;
 376           case 'l':  /* line */
 377             success = read_line(L, f);
 378             break;
 379           case 'a':  /* file */
 380             read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
 381             success = 1; /* always success */
 382             break;
 383           default:
 384             return luaL_argerror(L, n, "invalid format");
 385         }
 386       }
 387     }
 388   }
 389   if (ferror(f))
 390     return pushresult(L, 0, NULL);
 391   if (!success) {
 392     lua_pop(L, 1);  /* remove last result */
 393     lua_pushnil(L);  /* push nil instead */
 394   }
 395   return n - first;
 396 }
 397
 398
 399 static int io_read (lua_State *L) {
 400   return g_read(L, getiofile(L, IO_INPUT), 1);
 401 }
 402
 403
 404 static int f_read (lua_State *L) {
 405   return g_read(L, tofile(L), 2);
 406 }
 407
 408
 409 static int io_readline (lua_State *L) {
 410   FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
 411   int sucess;
 412   if (f == NULL)  /* file is already closed? */
 413     luaL_error(L, "file is already closed");
 414   sucess = read_line(L, f);
 415   if (ferror(f))
 416     return luaL_error(L, "%s", strerror(errno));
 417   if (sucess) return 1;
 418   else {  /* EOF */
 419     if (lua_toboolean(L, lua_upvalueindex(2))) {  /* generator created file? */
 420       lua_settop(L, 0);
 421       lua_pushvalue(L, lua_upvalueindex(1));
 422       aux_close(L);  /* close it */
 423     }
 424     return 0;
 425   }
 426 }
 427
 428 /* }====================================================== */
 429
 430
 431 static int g_write (lua_State *L, FILE *f, int arg) {
 432   int nargs = lua_gettop(L) - 1;
 433   int status = 1;
 434   for (; nargs--; arg++) {
 435     if (lua_type(L, arg) == LUA_TNUMBER) {
 436       /* optimization: could be done exactly as for strings */
 437       status = status &&
 438           fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
 439     }
 440     else {
 441       size_t l;
 442       const char *s = luaL_checklstring(L, arg, &l);
 443       status = status && (fwrite(s, sizeof(char), l, f) == l);
 444     }
 445   }
 446   return pushresult(L, status, NULL);
 447 }
 448
 449
 450 static int io_write (lua_State *L) {
 451   return g_write(L, getiofile(L, IO_OUTPUT), 1);
 452 }
 453
 454
 455 static int f_write (lua_State *L) {
 456   return g_write(L, tofile(L), 2);
 457 }
 458
 459 #ifndef NO_F_SEEK
 460 static int f_seek (lua_State *L) {
 461   static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
 462   static const char *const modenames[] = {"set", "cur", "end", NULL};
 463   FILE *f = tofile(L);
 464   int op = luaL_checkoption(L, 2, "cur", modenames);
 465   long offset = luaL_optlong(L, 3, 0);
 466   op = fseek(f, offset, mode[op]);
 467   if (op)
 468     return pushresult(L, 0, NULL);  /* error */
 469   else {
 470     lua_pushinteger(L, ftell(f));
 471     return 1;
 472   }
 473 }
 474 #endif
 475
 476 #ifndef NO_F_SETVBUF
 477 static int f_setvbuf (lua_State *L) {
 478   static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
 479   static const char *const modenames[] = {"no", "full", "line", NULL};
 480   FILE *f = tofile(L);
 481   int op = luaL_checkoption(L, 2, NULL, modenames);
 482   lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
 483   int res = setvbuf(f, NULL, mode[op], sz);
 484   return pushresult(L, res == 0, NULL);
 485 }
 486 #endif
 487
 488
 489 static int io_flush (lua_State *L) {
 490   return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
 491 }
 492
 493
 494 static int f_flush (lua_State *L) {
 495   return pushresult(L, fflush(tofile(L)) == 0, NULL);
 496 }
 497
 498
 499 static const luaL_Reg iolib[] = {
 500   {"close", io_close},
 501   {"flush", io_flush},
 502   {"input", io_input},
 503   {"lines", io_lines},
 504   {"open", io_open},
 505   {"output", io_output},
 506   {"popen", io_popen},
 507   {"read", io_read},
 508 #ifndef NO_TMP_FILE
 509   {"tmpfile", io_tmpfile},
 510 #endif
 511   {"type", io_type},
 512   {"write", io_write},
 513   {NULL, NULL}
 514 };
 515
 516
 517 static const luaL_Reg flib[] = {
 518   {"close", io_close},
 519   {"flush", f_flush},
 520   {"lines", f_lines},
 521   {"read", f_read},
 522 #ifndef NO_F_SEEK
 523   {"seek", f_seek},
 524 #endif
 525 #ifndef NO_F_SETVBUF
 526   {"setvbuf", f_setvbuf},
 527 #endif
 528   {"write", f_write},
 529   {"__gc", io_gc},
 530   {"__tostring", io_tostring},
 531   {NULL, NULL}
 532 };
 533
 534
 535 static void createmeta (lua_State *L) {
 536   luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
 537   lua_pushvalue(L, -1);  /* push metatable */
 538   lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
 539   luaL_register(L, NULL, flib);  /* file methods */
 540 }
 541
 542
 543 static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
 544   *newfile(L) = f;
 545   if (k > 0) {
 546     lua_pushvalue(L, -1);
 547     lua_rawseti(L, LUA_ENVIRONINDEX, k);
 548   }
 549   lua_pushvalue(L, -2);  /* copy environment */
 550   lua_setfenv(L, -2);  /* set it */
 551   lua_setfield(L, -3, fname);
 552 }
 553
 554
 555 static void newfenv (lua_State *L, lua_CFunction cls) {
 556   lua_createtable(L, 0, 1);
 557   lua_pushcfunction(L, cls);
 558   lua_setfield(L, -2, "__close");
 559 }
 560
 561
 562 LUALIB_API int luaopen_io (lua_State *L) {
 563   createmeta(L);
 564   /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
 565   newfenv(L, io_fclose);
 566   lua_replace(L, LUA_ENVIRONINDEX);
 567   /* open library */
 568   luaL_register(L, LUA_IOLIBNAME, iolib);
 569   /* create (and set) default files */
 570   newfenv(L, io_noclose);  /* close function for default files */
 571   createstdfile(L, stdin, IO_INPUT, "stdin");
 572   createstdfile(L, stdout, IO_OUTPUT, "stdout");
 573   createstdfile(L, stderr, 0, "stderr");
 574   lua_pop(L, 1);  /* pop environment for default files */
 575   lua_getfield(L, -1, "popen");
 576   newfenv(L, io_pclose);  /* create environment for 'popen' */
 577   lua_setfenv(L, -2);  /* set fenv for 'popen' */
 578   lua_pop(L, 1);  /* pop 'popen' */
 579   return 1;
 580 }
 581