external/mit/lua/dist/src/liolib.c

   1 /*      $NetBSD: liolib.c,v 1.1.1.2 2012/03/15 00:08:04 alnsn Exp $     */
   2
   3 /*
   4 ** $Id: liolib.c,v 1.1.1.2 2012/03/15 00:08:04 alnsn Exp $
   5 ** Standard I/O (and system) library
   6 ** See Copyright Notice in lua.h
   7 */
   8
   9
  10 #include <errno.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15 #define liolib_c
  16 #define LUA_LIB
  17
  18 #include "lua.h"
  19
  20 #include "lauxlib.h"
  21 #include "lualib.h"
  22
  23
  24
  25 #define IO_INPUT        1
  26 #define IO_OUTPUT       2
  27
  28
  29 static const char *const fnames[] = {"input", "output"};
  30
  31
  32 static int pushresult (lua_State *L, int i, const char *filename) {
  33   int en = errno;  /* calls to Lua API may change this value */
  34   if (i) {
  35     lua_pushboolean(L, 1);
  36     return 1;
  37   }
  38   else {
  39     lua_pushnil(L);
  40     if (filename)
  41       lua_pushfstring(L, "%s: %s", filename, strerror(en));
  42     else
  43       lua_pushfstring(L, "%s", strerror(en));
  44     lua_pushinteger(L, en);
  45     return 3;
  46   }
  47 }
  48
  49
  50 static void fileerror (lua_State *L, int arg, const char *filename) {
  51   lua_pushfstring(L, "%s: %s", filename, strerror(errno));
  52   luaL_argerror(L, arg, lua_tostring(L, -1));
  53 }
  54
  55
  56 #define tofilep(L)      ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
  57
  58
  59 static int io_type (lua_State *L) {
  60   void *ud;
  61   luaL_checkany(L, 1);
  62   ud = lua_touserdata(L, 1);
  63   lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
  64   if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
  65     lua_pushnil(L);  /* not a file */
  66   else if (*((FILE **)ud) == NULL)
  67     lua_pushliteral(L, "closed file");
  68   else
  69     lua_pushliteral(L, "file");
  70   return 1;
  71 }
  72
  73
  74 static FILE *tofile (lua_State *L) {
  75   FILE **f = tofilep(L);
  76   if (*f == NULL)
  77     luaL_error(L, "attempt to use a closed file");
  78   return *f;
  79 }
  80
  81
  82
  83 /*
  84 ** When creating file handles, always creates a `closed' file handle
  85 ** before opening the actual file; so, if there is a memory error, the
  86 ** file is not left opened.
  87 */
  88 static FILE **newfile (lua_State *L) {
  89   FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
  90   *pf = NULL;  /* file handle is currently `closed' */
  91   luaL_getmetatable(L, LUA_FILEHANDLE);
  92   lua_setmetatable(L, -2);
  93   return pf;
  94 }
  95
  96
  97 /*
  98 ** function to (not) close the standard files stdin, stdout, and stderr
  99 */
 100 static int io_noclose (lua_State *L) {
 101   lua_pushnil(L);
 102   lua_pushliteral(L, "cannot close standard file");
 103   return 2;
 104 }
 105
 106
 107 /*
 108 ** function to close 'popen' files
 109 */
 110 static int io_pclose (lua_State *L) {
 111   FILE **p = tofilep(L);
 112   int ok = lua_pclose(L, *p);
 113   *p = NULL;
 114   return pushresult(L, ok, NULL);
 115 }
 116
 117
 118 /*
 119 ** function to close regular files
 120 */
 121 static int io_fclose (lua_State *L) {
 122   FILE **p = tofilep(L);
 123   int ok = (fclose(*p) == 0);
 124   *p = NULL;
 125   return pushresult(L, ok, NULL);
 126 }
 127
 128
 129 static int aux_close (lua_State *L) {
 130   lua_getfenv(L, 1);
 131   lua_getfield(L, -1, "__close");
 132   return (lua_tocfunction(L, -1))(L);
 133 }
 134
 135
 136 static int io_close (lua_State *L) {
 137   if (lua_isnone(L, 1))
 138     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
 139   tofile(L);  /* make sure argument is a file */
 140   return aux_close(L);
 141 }
 142
 143
 144 static int io_gc (lua_State *L) {
 145   FILE *f = *tofilep(L);
 146   /* ignore closed files */
 147   if (f != NULL)
 148     aux_close(L);
 149   return 0;
 150 }
 151
 152
 153 static int io_tostring (lua_State *L) {
 154   FILE *f = *tofilep(L);
 155   if (f == NULL)
 156     lua_pushliteral(L, "file (closed)");
 157   else
 158     lua_pushfstring(L, "file (%p)", f);
 159   return 1;
 160 }
 161
 162
 163 static int io_open (lua_State *L) {
 164   const char *filename = luaL_checkstring(L, 1);
 165   const char *mode = luaL_optstring(L, 2, "r");
 166   FILE **pf = newfile(L);
 167   *pf = fopen(filename, mode);
 168   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 169 }
 170
 171
 172 /*
 173 ** this function has a separated environment, which defines the
 174 ** correct __close for 'popen' files
 175 */
 176 static int io_popen (lua_State *L) {
 177   const char *filename = luaL_checkstring(L, 1);
 178   const char *mode = luaL_optstring(L, 2, "r");
 179   FILE **pf = newfile(L);
 180   *pf = lua_popen(L, filename, mode);
 181   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 182 }
 183
 184
 185 static int io_tmpfile (lua_State *L) {
 186   FILE **pf = newfile(L);
 187   *pf = tmpfile();
 188   return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
 189 }
 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
 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 {
 282     lua_pushnil(L);  /* "result" to be removed */
 283     return 0;  /* read fails */
 284   }
 285 }
 286
 287
 288 static int test_eof (lua_State *L, FILE *f) {
 289   int c = getc(f);
 290   ungetc(c, f);
 291   lua_pushlstring(L, NULL, 0);
 292   return (c != EOF);
 293 }
 294
 295
 296 static int read_line (lua_State *L, FILE *f) {
 297   luaL_Buffer b;
 298   luaL_buffinit(L, &b);
 299   for (;;) {
 300     size_t l;
 301     char *p = luaL_prepbuffer(&b);
 302     if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) {  /* eof? */
 303       luaL_pushresult(&b);  /* close buffer */
 304       return (lua_objlen(L, -1) > 0);  /* check whether read something */
 305     }
 306     l = strlen(p);
 307     if (l == 0 || p[l-1] != '\n')
 308       luaL_addsize(&b, l);
 309     else {
 310       luaL_addsize(&b, l - 1);  /* do not include `eol' */
 311       luaL_pushresult(&b);  /* close buffer */
 312       return 1;  /* read at least an `eol' */
 313     }
 314   }
 315 }
 316
 317
 318 static int read_chars (lua_State *L, FILE *f, size_t n) {
 319   size_t rlen;  /* how much to read */
 320   size_t nr;  /* number of chars actually read */
 321   luaL_Buffer b;
 322   luaL_buffinit(L, &b);
 323   rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
 324   do {
 325     char *p = luaL_prepbuffer(&b);
 326     if (rlen > n) rlen = n;  /* cannot read more than asked */
 327     nr = fread(p, sizeof(char), rlen, f);
 328     luaL_addsize(&b, nr);
 329     n -= nr;  /* still have to read `n' chars */
 330   } while (n > 0 && nr == rlen);  /* until end of count or eof */
 331   luaL_pushresult(&b);  /* close buffer */
 332   return (n == 0 || lua_objlen(L, -1) > 0);
 333 }
 334
 335
 336 static int g_read (lua_State *L, FILE *f, int first) {
 337   int nargs = lua_gettop(L) - 1;
 338   int success;
 339   int n;
 340   clearerr(f);
 341   if (nargs == 0) {  /* no arguments? */
 342     success = read_line(L, f);
 343     n = first+1;  /* to return 1 result */
 344   }
 345   else {  /* ensure stack space for all results and for auxlib's buffer */
 346     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
 347     success = 1;
 348     for (n = first; nargs-- && success; n++) {
 349       if (lua_type(L, n) == LUA_TNUMBER) {
 350         size_t l = (size_t)lua_tointeger(L, n);
 351         success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
 352       }
 353       else {
 354         const char *p = lua_tostring(L, n);
 355         luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
 356         switch (p[1]) {
 357           case 'n':  /* number */
 358             success = read_number(L, f);
 359             break;
 360           case 'l':  /* line */
 361             success = read_line(L, f);
 362             break;
 363           case 'a':  /* file */
 364             read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
 365             success = 1; /* always success */
 366             break;
 367           default:
 368             return luaL_argerror(L, n, "invalid format");
 369         }
 370       }
 371     }
 372   }
 373   if (ferror(f))
 374     return pushresult(L, 0, NULL);
 375   if (!success) {
 376     lua_pop(L, 1);  /* remove last result */
 377     lua_pushnil(L);  /* push nil instead */
 378   }
 379   return n - first;
 380 }
 381
 382
 383 static int io_read (lua_State *L) {
 384   return g_read(L, getiofile(L, IO_INPUT), 1);
 385 }
 386
 387
 388 static int f_read (lua_State *L) {
 389   return g_read(L, tofile(L), 2);
 390 }
 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
 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
 459
 460 static int f_setvbuf (lua_State *L) {
 461   static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
 462   static const char *const modenames[] = {"no", "full", "line", NULL};
 463   FILE *f = tofile(L);
 464   int op = luaL_checkoption(L, 2, NULL, modenames);
 465   lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
 466   int res = setvbuf(f, NULL, mode[op], sz);
 467   return pushresult(L, res == 0, NULL);
 468 }
 469
 470
 471
 472 static int io_flush (lua_State *L) {
 473   return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
 474 }
 475
 476
 477 static int f_flush (lua_State *L) {
 478   return pushresult(L, fflush(tofile(L)) == 0, NULL);
 479 }
 480
 481
 482 static const luaL_Reg iolib[] = {
 483   {"close", io_close},
 484   {"flush", io_flush},
 485   {"input", io_input},
 486   {"lines", io_lines},
 487   {"open", io_open},
 488   {"output", io_output},
 489   {"popen", io_popen},
 490   {"read", io_read},
 491   {"tmpfile", io_tmpfile},
 492   {"type", io_type},
 493   {"write", io_write},
 494   {NULL, NULL}
 495 };
 496
 497
 498 static const luaL_Reg flib[] = {
 499   {"close", io_close},
 500   {"flush", f_flush},
 501   {"lines", f_lines},
 502   {"read", f_read},
 503   {"seek", f_seek},
 504   {"setvbuf", f_setvbuf},
 505   {"write", f_write},
 506   {"__gc", io_gc},
 507   {"__tostring", io_tostring},
 508   {NULL, NULL}
 509 };
 510
 511
 512 static void createmeta (lua_State *L) {
 513   luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
 514   lua_pushvalue(L, -1);  /* push metatable */
 515   lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
 516   luaL_register(L, NULL, flib);  /* file methods */
 517 }
 518
 519
 520 static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
 521   *newfile(L) = f;
 522   if (k > 0) {
 523     lua_pushvalue(L, -1);
 524     lua_rawseti(L, LUA_ENVIRONINDEX, k);
 525   }
 526   lua_pushvalue(L, -2);  /* copy environment */
 527   lua_setfenv(L, -2);  /* set it */
 528   lua_setfield(L, -3, fname);
 529 }
 530
 531
 532 static void newfenv (lua_State *L, lua_CFunction cls) {
 533   lua_createtable(L, 0, 1);
 534   lua_pushcfunction(L, cls);
 535   lua_setfield(L, -2, "__close");
 536 }
 537
 538
 539 LUALIB_API int luaopen_io (lua_State *L) {
 540   createmeta(L);
 541   /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
 542   newfenv(L, io_fclose);
 543   lua_replace(L, LUA_ENVIRONINDEX);
 544   /* open library */
 545   luaL_register(L, LUA_IOLIBNAME, iolib);
 546   /* create (and set) default files */
 547   newfenv(L, io_noclose);  /* close function for default files */
 548   createstdfile(L, stdin, IO_INPUT, "stdin");
 549   createstdfile(L, stdout, IO_OUTPUT, "stdout");
 550   createstdfile(L, stderr, 0, "stderr");
 551   lua_pop(L, 1);  /* pop environment for default files */
 552   lua_getfield(L, -1, "popen");
 553   newfenv(L, io_pclose);  /* create environment for 'popen' */
 554   lua_setfenv(L, -2);  /* set fenv for 'popen' */
 555   lua_pop(L, 1);  /* pop 'popen' */
 556   return 1;
 557 }
 558