com32/lua/src/liolib.c

   1 /*
   2 ** $Id: liolib.c,v 2.73.1.3 2008/01/18 17:47:43 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
  22
  23 #define IO_INPUT        1
  24 #define IO_OUTPUT       2
  25
  26
  27 static const char *const fnames[] = {"input", "output"};
  28
  29
  30 static int pushresult (lua_State *L, int i, const char *filename) {
  31   int en = errno;  /* calls to Lua API may change this value */
  32   if (i) {
  33     lua_pushboolean(L, 1);
  34     return 1;
  35   }
  36   else {
  37     lua_pushnil(L);
  38     if (filename)
  39       lua_pushfstring(L, "%s: %s", filename, strerror(en));
  40     else
  41       lua_pushfstring(L, "%s", strerror(en));
  42     lua_pushinteger(L, en);
  43     return 3;
  44   }
  45 }
  46
  47
  48 static void fileerror (lua_State *L, int arg, const char *filename) {
  49   lua_pushfstring(L, "%s: %s", filename, strerror(errno));
  50   luaL_argerror(L, arg, lua_tostring(L, -1));
  51 }
  52
  53
  54 #define tofilep(L)      ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
  55
  56
  57 static int io_type (lua_State *L) {
  58   void *ud;
  59   luaL_checkany(L, 1);
  60   ud = lua_touserdata(L, 1);
  61   lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
  62   if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
  63     lua_pushnil(L);  /* not a file */
  64   else if (*((FILE **)ud) == NULL)
  65     lua_pushliteral(L, "closed file");
  66   else
  67     lua_pushliteral(L, "file");
  68   return 1;
  69 }
  70
  71
  72 static FILE *tofile (lua_State *L) {
  73   FILE **f = tofilep(L);
  74   if (*f == NULL)
  75     luaL_error(L, "attempt to use a closed file");
  76   return *f;
  77 }
  78
  79
  80
  81 /*
  82 ** When creating file handles, always creates a `closed' file handle
  83 ** before opening the actual file; so, if there is a memory error, the
  84 ** file is not left opened.
  85 */
  86 static FILE **newfile (lua_State *L) {
  87   FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
  88   *pf = NULL;  /* file handle is currently `closed' */
  89   luaL_getmetatable(L, LUA_FILEHANDLE);
  90   lua_setmetatable(L, -2);
  91   return pf;
  92 }
  93
  94
  95 /*
  96 ** function to (not) close the standard files stdin, stdout, and stderr
  97 */
  98 static int io_noclose (lua_State *L) {
  99   lua_pushnil(L);
 100   lua_pushliteral(L, "cannot close standard file");
 101   return 2;
 102 }
 103
 104
 105 /*
 106 ** function to close 'popen' files
 107 */
 108 static int io_pclose (lua_State *L) {
 109   FILE **p = tofilep(L);
 110   int ok = lua_pclose(L, *p);
 111   *p = NULL;
 112   return pushresult(L, ok, NULL);
 113 }
 114
 115
 116 /*
 117 ** function to close regular files
 118 */
 119 static int io_fclose (lua_State *L) {
 120   FILE **p = tofilep(L);
 121   int ok = (fclose(*p) == 0);
 122   *p = NULL;
 123   return pushresult(L, ok, NULL);
 124 }
 125
 126
 127 static int aux_close (lua_State *L) {
 128   lua_getfenv(L, 1);
 129   lua_getfield(L, -1, "__close");
 130   return (lua_tocfunction(L, -1))(L);
 131 }
 132
 133
 134 static int io_close (lua_State *L) {
 135   if (lua_isnone(L, 1))
 136     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
 137   tofile(L);  /* make sure argument is a file */
 138   return aux_close(L);
 139 }
 140
 141
 142 static int io_gc (lua_State *L) {
 143   FILE *f = *tofilep(L);
 144   /* ignore closed files */
 145   if (f != NULL)
 146     aux_close(L);
 147   return 0;
 148 }
 149
 150
 151 static int io_tostring (lua_State *L) {
 152   FILE *f = *tofilep(L);
 153   if (f == NULL)
 154     lua_pushliteral(L, "file (closed)");
 155   else
 156     lua_pushfstring(L, "file (%p)", f);
 157   return 1;
 158 }
 159
 160
 161 static int io_open (lua_State *L) {
 162   const char *filename = luaL_checkstring(L, 1);
 163   const char *mode = luaL_optstring(L, 2, "r");
 164   FILE **pf = newfile(L);
 165   *pf = fopen(filename, mode);
 166   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 167 }
 168
 169
 170 /*
 171 ** this function has a separated environment, which defines the
 172 ** correct __close for 'popen' files
 173 */
 174 static int io_popen (lua_State *L) {
 175   const char *filename = luaL_checkstring(L, 1);
 176   const char *mode = luaL_optstring(L, 2, "r");
 177   FILE **pf = newfile(L);
 178   *pf = lua_popen(L, filename, mode);
 179   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 180 }
 181
 182
 183 #if 0
 184 static int io_tmpfile (lua_State *L) {
 185   FILE **pf = newfile(L);
 186   *pf = tmpfile();
 187   return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
 188 }
 189 #endif
 190
 191
 192 static FILE *getiofile (lua_State *L, int findex) {
 193   FILE *f;
 194   lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
 195   f = *(FILE **)lua_touserdata(L, -1);
 196   if (f == NULL)
 197     luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
 198   return f;
 199 }
 200
 201
 202 static int g_iofile (lua_State *L, int f, const char *mode) {
 203   if (!lua_isnoneornil(L, 1)) {
 204     const char *filename = lua_tostring(L, 1);
 205     if (filename) {
 206       FILE **pf = newfile(L);
 207       *pf = fopen(filename, mode);
 208       if (*pf == NULL)
 209         fileerror(L, 1, filename);
 210     }
 211     else {
 212       tofile(L);  /* check that it's a valid file handle */
 213       lua_pushvalue(L, 1);
 214     }
 215     lua_rawseti(L, LUA_ENVIRONINDEX, f);
 216   }
 217   /* return current value */
 218   lua_rawgeti(L, LUA_ENVIRONINDEX, f);
 219   return 1;
 220 }
 221
 222
 223 static int io_input (lua_State *L) {
 224   return g_iofile(L, IO_INPUT, "r");
 225 }
 226
 227
 228 static int io_output (lua_State *L) {
 229   return g_iofile(L, IO_OUTPUT, "w");
 230 }
 231
 232
 233 static int io_readline (lua_State *L);
 234
 235
 236 static void aux_lines (lua_State *L, int idx, int toclose) {
 237   lua_pushvalue(L, idx);
 238   lua_pushboolean(L, toclose);  /* close/not close file when finished */
 239   lua_pushcclosure(L, io_readline, 2);
 240 }
 241
 242
 243 static int f_lines (lua_State *L) {
 244   tofile(L);  /* check that it's a valid file handle */
 245   aux_lines(L, 1, 0);
 246   return 1;
 247 }
 248
 249
 250 static int io_lines (lua_State *L) {
 251   if (lua_isnoneornil(L, 1)) {  /* no arguments? */
 252     /* will iterate over default input */
 253     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
 254     return f_lines(L);
 255   }
 256   else {
 257     const char *filename = luaL_checkstring(L, 1);
 258     FILE **pf = newfile(L);
 259     *pf = fopen(filename, "r");
 260     if (*pf == NULL)
 261       fileerror(L, 1, filename);
 262     aux_lines(L, lua_gettop(L), 1);
 263     return 1;
 264   }
 265 }
 266
 267
 268 /*
 269 ** {======================================================
 270 ** READ
 271 ** =======================================================
 272 */
 273
 274 #if 0
 275 static int read_number (lua_State *L, FILE *f) {
 276   lua_Number d;
 277   if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
 278     lua_pushnumber(L, d);
 279     return 1;
 280   }
 281   else return 0;  /* read fails */
 282 }
 283
 284
 285 static int test_eof (lua_State *L, FILE *f) {
 286   int c = getc(f);
 287   ungetc(c, f);
 288   lua_pushlstring(L, NULL, 0);
 289   return (c != EOF);
 290 }
 291 #endif
 292
 293
 294 static int read_line (lua_State *L, FILE *f) {
 295   luaL_Buffer b;
 296   luaL_buffinit(L, &b);
 297   for (;;) {
 298     size_t l;
 299     char *p = luaL_prepbuffer(&b);
 300     if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) {  /* eof? */
 301       luaL_pushresult(&b);  /* close buffer */
 302       return (lua_objlen(L, -1) > 0);  /* check whether read something */
 303     }
 304     l = strlen(p);
 305     if (l == 0 || p[l-1] != '\n')
 306       luaL_addsize(&b, l);
 307     else {
 308       luaL_addsize(&b, l - 1);  /* do not include `eol' */
 309       luaL_pushresult(&b);  /* close buffer */
 310       return 1;  /* read at least an `eol' */
 311     }
 312   }
 313 }
 314
 315 #if 0                           /* Not used */
 316 static int read_chars (lua_State *L, FILE *f, size_t n) {
 317   size_t rlen;  /* how much to read */
 318   size_t nr;  /* number of chars actually read */
 319   luaL_Buffer b;
 320   luaL_buffinit(L, &b);
 321   rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
 322   do {
 323     char *p = luaL_prepbuffer(&b);
 324     if (rlen > n) rlen = n;  /* cannot read more than asked */
 325     nr = fread(p, sizeof(char), rlen, f);
 326     luaL_addsize(&b, nr);
 327     n -= nr;  /* still have to read `n' chars */
 328   } while (n > 0 && nr == rlen);  /* until end of count or eof */
 329   luaL_pushresult(&b);  /* close buffer */
 330   return (n == 0 || lua_objlen(L, -1) > 0);
 331 }
 332 #endif
 333
 334 #if 0
 335 static int g_read (lua_State *L, FILE *f, int first) {
 336   int nargs = lua_gettop(L) - 1;
 337   int success;
 338   int n;
 339   clearerr(f);
 340   if (nargs == 0) {  /* no arguments? */
 341     success = read_line(L, f);
 342     n = first+1;  /* to return 1 result */
 343   }
 344   else {  /* ensure stack space for all results and for auxlib's buffer */
 345     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
 346     success = 1;
 347     for (n = first; nargs-- && success; n++) {
 348       if (lua_type(L, n) == LUA_TNUMBER) {
 349         size_t l = (size_t)lua_tointeger(L, n);
 350         success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
 351       }
 352       else {
 353         const char *p = lua_tostring(L, n);
 354         luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
 355         switch (p[1]) {
 356           case 'n':  /* number */
 357             success = read_number(L, f);
 358             break;
 359           case 'l':  /* line */
 360             success = read_line(L, f);
 361             break;
 362           case 'a':  /* file */
 363             read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
 364             success = 1; /* always success */
 365             break;
 366           default:
 367             return luaL_argerror(L, n, "invalid format");
 368         }
 369       }
 370     }
 371   }
 372   if (ferror(f))
 373     return pushresult(L, 0, NULL);
 374   if (!success) {
 375     lua_pop(L, 1);  /* remove last result */
 376     lua_pushnil(L);  /* push nil instead */
 377   }
 378   return n - first;
 379 }
 380
 381
 382 static int io_read (lua_State *L) {
 383   return g_read(L, getiofile(L, IO_INPUT), 1);
 384 }
 385
 386
 387 static int f_read (lua_State *L) {
 388   return g_read(L, tofile(L), 2);
 389 }
 390 #endif
 391
 392
 393 static int io_readline (lua_State *L) {
 394   FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
 395   int sucess;
 396   if (f == NULL)  /* file is already closed? */
 397     luaL_error(L, "file is already closed");
 398   sucess = read_line(L, f);
 399   if (ferror(f))
 400     return luaL_error(L, "%s", strerror(errno));
 401   if (sucess) return 1;
 402   else {  /* EOF */
 403     if (lua_toboolean(L, lua_upvalueindex(2))) {  /* generator created file? */
 404       lua_settop(L, 0);
 405       lua_pushvalue(L, lua_upvalueindex(1));
 406       aux_close(L);  /* close it */
 407     }
 408     return 0;
 409   }
 410 }
 411
 412 /* }====================================================== */
 413
 414
 415 static int g_write (lua_State *L, FILE *f, int arg) {
 416   int nargs = lua_gettop(L) - 1;
 417   int status = 1;
 418   for (; nargs--; arg++) {
 419     if (lua_type(L, arg) == LUA_TNUMBER) {
 420       /* optimization: could be done exactly as for strings */
 421       status = status &&
 422           fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
 423     }
 424     else {
 425       size_t l;
 426       const char *s = luaL_checklstring(L, arg, &l);
 427       status = status && (fwrite(s, sizeof(char), l, f) == l);
 428     }
 429   }
 430   return pushresult(L, status, NULL);
 431 }
 432
 433
 434 static int io_write (lua_State *L) {
 435   return g_write(L, getiofile(L, IO_OUTPUT), 1);
 436 }
 437
 438
 439 static int f_write (lua_State *L) {
 440   return g_write(L, tofile(L), 2);
 441 }
 442
 443 #if 0
 444 static int f_seek (lua_State *L) {
 445   static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
 446   static const char *const modenames[] = {"set", "cur", "end", NULL};
 447   FILE *f = tofile(L);
 448   int op = luaL_checkoption(L, 2, "cur", modenames);
 449   long offset = luaL_optlong(L, 3, 0);
 450   op = fseek(f, offset, mode[op]);
 451   if (op)
 452     return pushresult(L, 0, NULL);  /* error */
 453   else {
 454     lua_pushinteger(L, ftell(f));
 455     return 1;
 456   }
 457 }
 458 #endif
 459
 460
 461 #if 0
 462 static int f_setvbuf (lua_State *L) {
 463   static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
 464   static const char *const modenames[] = {"no", "full", "line", NULL};
 465   FILE *f = tofile(L);
 466   int op = luaL_checkoption(L, 2, NULL, modenames);
 467   lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
 468   int res = setvbuf(f, NULL, mode[op], sz);
 469   return pushresult(L, res == 0, NULL);
 470 }
 471 #endif
 472
 473
 474 static int io_flush (lua_State *L) {
 475   return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
 476 }
 477
 478
 479 static int f_flush (lua_State *L) {
 480   return pushresult(L, fflush(tofile(L)) == 0, NULL);
 481 }
 482
 483
 484 static const luaL_Reg iolib[] = {
 485   {"close", io_close},
 486   {"flush", io_flush},
 487   {"input", io_input},
 488   {"lines", io_lines},
 489   {"open", io_open},
 490   {"output", io_output},
 491   {"popen", io_popen},
 492 /*  {"read", io_read}, */
 493 /*  {"tmpfile", io_tmpfile}, */
 494   {"type", io_type},
 495   {"write", io_write},
 496   {NULL, NULL}
 497 };
 498
 499
 500 static const luaL_Reg flib[] = {
 501   {"close", io_close},
 502   {"flush", f_flush},
 503   {"lines", f_lines},
 504 /*  {"read", f_read}, */
 505 /*  {"seek", f_seek}, */
 506 /*  {"setvbuf", f_setvbuf}, */
 507   {"write", f_write},
 508   {"__gc", io_gc},
 509   {"__tostring", io_tostring},
 510   {NULL, NULL}
 511 };
 512
 513
 514 static void createmeta (lua_State *L) {
 515   luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
 516   lua_pushvalue(L, -1);  /* push metatable */
 517   lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
 518   luaL_register(L, NULL, flib);  /* file methods */
 519 }
 520
 521
 522 static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
 523   *newfile(L) = f;
 524   if (k > 0) {
 525     lua_pushvalue(L, -1);
 526     lua_rawseti(L, LUA_ENVIRONINDEX, k);
 527   }
 528   lua_pushvalue(L, -2);  /* copy environment */
 529   lua_setfenv(L, -2);  /* set it */
 530   lua_setfield(L, -3, fname);
 531 }
 532
 533
 534 static void newfenv (lua_State *L, lua_CFunction cls) {
 535   lua_createtable(L, 0, 1);
 536   lua_pushcfunction(L, cls);
 537   lua_setfield(L, -2, "__close");
 538 }
 539
 540
 541 LUALIB_API int luaopen_io (lua_State *L) {
 542   createmeta(L);
 543   /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
 544   newfenv(L, io_fclose);
 545   lua_replace(L, LUA_ENVIRONINDEX);
 546   /* open library */
 547   luaL_register(L, LUA_IOLIBNAME, iolib);
 548   /* create (and set) default files */
 549   newfenv(L, io_noclose);  /* close function for default files */
 550   createstdfile(L, stdin, IO_INPUT, "stdin");
 551   createstdfile(L, stdout, IO_OUTPUT, "stdout");
 552   createstdfile(L, stderr, 0, "stderr");
 553   lua_pop(L, 1);  /* pop environment for default files */
 554   lua_getfield(L, -1, "popen");
 555   newfenv(L, io_pclose);  /* create environment for 'popen' */
 556   lua_setfenv(L, -2);  /* set fenv for 'popen' */
 557   lua_pop(L, 1);  /* pop 'popen' */
 558   return 1;
 559 }
 560