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 static int io_tmpfile (lua_State *L) { 184 FILE **pf = newfile(L); 185 *pf = tmpfile(); 186 return (*pf == NULL) ? pushresult(L, 0, NULL) : 1; 187 } 188 189 190 static FILE *getiofile (lua_State *L, int findex) { 191 FILE *f; 192 lua_rawgeti(L, LUA_ENVIRONINDEX, findex); 193 f = *(FILE **)lua_touserdata(L, -1); 194 if (f == NULL) 195 luaL_error(L, "standard %s file is closed", fnames[findex - 1]); 196 return f; 197 } 198 199 200 static int g_iofile (lua_State *L, int f, const char *mode) { 201 if (!lua_isnoneornil(L, 1)) { 202 const char *filename = lua_tostring(L, 1); 203 if (filename) { 204 FILE **pf = newfile(L); 205 *pf = fopen(filename, mode); 206 if (*pf == NULL) 207 fileerror(L, 1, filename); 208 } 209 else { 210 tofile(L); /* check that it's a valid file handle */ 211 lua_pushvalue(L, 1); 212 } 213 lua_rawseti(L, LUA_ENVIRONINDEX, f); 214 } 215 /* return current value */ 216 lua_rawgeti(L, LUA_ENVIRONINDEX, f); 217 return 1; 218 } 219 220 221 static int io_input (lua_State *L) { 222 return g_iofile(L, IO_INPUT, "r"); 223 } 224 225 226 static int io_output (lua_State *L) { 227 return g_iofile(L, IO_OUTPUT, "w"); 228 } 229 230 231 static int io_readline (lua_State *L); 232 233 234 static void aux_lines (lua_State *L, int idx, int toclose) { 235 lua_pushvalue(L, idx); 236 lua_pushboolean(L, toclose); /* close/not close file when finished */ 237 lua_pushcclosure(L, io_readline, 2); 238 } 239 240 241 static int f_lines (lua_State *L) { 242 tofile(L); /* check that it's a valid file handle */ 243 aux_lines(L, 1, 0); 244 return 1; 245 } 246 247 248 static int io_lines (lua_State *L) { 249 if (lua_isnoneornil(L, 1)) { /* no arguments? */ 250 /* will iterate over default input */ 251 lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT); 252 return f_lines(L); 253 } 254 else { 255 const char *filename = luaL_checkstring(L, 1); 256 FILE **pf = newfile(L); 257 *pf = fopen(filename, "r"); 258 if (*pf == NULL) 259 fileerror(L, 1, filename); 260 aux_lines(L, lua_gettop(L), 1); 261 return 1; 262 } 263 } 264 265 266 /* 267 ** {====================================================== 268 ** READ 269 ** ======================================================= 270 */ 271 272 273 static int read_number (lua_State *L, FILE *f) { 274 lua_Number d; 275 if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) { 276 lua_pushnumber(L, d); 277 return 1; 278 } 279 else return 0; /* read fails */ 280 } 281 282 283 static int test_eof (lua_State *L, FILE *f) { 284 int c = getc(f); 285 ungetc(c, f); 286 lua_pushlstring(L, NULL, 0); 287 return (c != EOF); 288 } 289 290 291 static int read_line (lua_State *L, FILE *f) { 292 luaL_Buffer b; 293 luaL_buffinit(L, &b); 294 for (;;) { 295 size_t l; 296 char *p = luaL_prepbuffer(&b); 297 if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */ 298 luaL_pushresult(&b); /* close buffer */ 299 return (lua_objlen(L, -1) > 0); /* check whether read something */ 300 } 301 l = strlen(p); 302 if (l == 0 || p[l-1] != '\n') 303 luaL_addsize(&b, l); 304 else { 305 luaL_addsize(&b, l - 1); /* do not include `eol' */ 306 luaL_pushresult(&b); /* close buffer */ 307 return 1; /* read at least an `eol' */ 308 } 309 } 310 } 311 312 313 static int read_chars (lua_State *L, FILE *f, size_t n) { 314 size_t rlen; /* how much to read */ 315 size_t nr; /* number of chars actually read */ 316 luaL_Buffer b; 317 luaL_buffinit(L, &b); 318 rlen = LUAL_BUFFERSIZE; /* try to read that much each time */ 319 do { 320 char *p = luaL_prepbuffer(&b); 321 if (rlen > n) rlen = n; /* cannot read more than asked */ 322 nr = fread(p, sizeof(char), rlen, f); 323 luaL_addsize(&b, nr); 324 n -= nr; /* still have to read `n' chars */ 325 } while (n > 0 && nr == rlen); /* until end of count or eof */ 326 luaL_pushresult(&b); /* close buffer */ 327 return (n == 0 || lua_objlen(L, -1) > 0); 328 } 329 330 331 static int g_read (lua_State *L, FILE *f, int first) { 332 int nargs = lua_gettop(L) - 1; 333 int success; 334 int n; 335 clearerr(f); 336 if (nargs == 0) { /* no arguments? */ 337 success = read_line(L, f); 338 n = first+1; /* to return 1 result */ 339 } 340 else { /* ensure stack space for all results and for auxlib's buffer */ 341 luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); 342 success = 1; 343 for (n = first; nargs-- && success; n++) { 344 if (lua_type(L, n) == LUA_TNUMBER) { 345 size_t l = (size_t)lua_tointeger(L, n); 346 success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); 347 } 348 else { 349 const char *p = lua_tostring(L, n); 350 luaL_argcheck(L, p && p[0] == '*', n, "invalid option"); 351 switch (p[1]) { 352 case 'n': /* number */ 353 success = read_number(L, f); 354 break; 355 case 'l': /* line */ 356 success = read_line(L, f); 357 break; 358 case 'a': /* file */ 359 read_chars(L, f, ~((size_t)0)); /* read MAX_SIZE_T chars */ 360 success = 1; /* always success */ 361 break; 362 default: 363 return luaL_argerror(L, n, "invalid format"); 364 } 365 } 366 } 367 } 368 if (ferror(f)) 369 return pushresult(L, 0, NULL); 370 if (!success) { 371 lua_pop(L, 1); /* remove last result */ 372 lua_pushnil(L); /* push nil instead */ 373 } 374 return n - first; 375 } 376 377 378 static int io_read (lua_State *L) { 379 return g_read(L, getiofile(L, IO_INPUT), 1); 380 } 381 382 383 static int f_read (lua_State *L) { 384 return g_read(L, tofile(L), 2); 385 } 386 387 388 static int io_readline (lua_State *L) { 389 FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1)); 390 int sucess; 391 if (f == NULL) /* file is already closed? */ 392 luaL_error(L, "file is already closed"); 393 sucess = read_line(L, f); 394 if (ferror(f)) 395 return luaL_error(L, "%s", strerror(errno)); 396 if (sucess) return 1; 397 else { /* EOF */ 398 if (lua_toboolean(L, lua_upvalueindex(2))) { /* generator created file? */ 399 lua_settop(L, 0); 400 lua_pushvalue(L, lua_upvalueindex(1)); 401 aux_close(L); /* close it */ 402 } 403 return 0; 404 } 405 } 406 407 /* }====================================================== */ 408 409 410 static int g_write (lua_State *L, FILE *f, int arg) { 411 int nargs = lua_gettop(L) - 1; 412 int status = 1; 413 for (; nargs--; arg++) { 414 if (lua_type(L, arg) == LUA_TNUMBER) { 415 /* optimization: could be done exactly as for strings */ 416 status = status && 417 fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0; 418 } 419 else { 420 size_t l; 421 const char *s = luaL_checklstring(L, arg, &l); 422 status = status && (fwrite(s, sizeof(char), l, f) == l); 423 } 424 } 425 return pushresult(L, status, NULL); 426 } 427 428 429 static int io_write (lua_State *L) { 430 return g_write(L, getiofile(L, IO_OUTPUT), 1); 431 } 432 433 434 static int f_write (lua_State *L) { 435 return g_write(L, tofile(L), 2); 436 } 437 438 439 static int f_seek (lua_State *L) { 440 static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; 441 static const char *const modenames[] = {"set", "cur", "end", NULL}; 442 FILE *f = tofile(L); 443 int op = luaL_checkoption(L, 2, "cur", modenames); 444 long offset = luaL_optlong(L, 3, 0); 445 op = fseek(f, offset, mode[op]); 446 if (op) 447 return pushresult(L, 0, NULL); /* error */ 448 else { 449 lua_pushinteger(L, ftell(f)); 450 return 1; 451 } 452 } 453 454 455 static int f_setvbuf (lua_State *L) { 456 static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; 457 static const char *const modenames[] = {"no", "full", "line", NULL}; 458 FILE *f = tofile(L); 459 int op = luaL_checkoption(L, 2, NULL, modenames); 460 lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); 461 int res = setvbuf(f, NULL, mode[op], sz); 462 return pushresult(L, res == 0, NULL); 463 } 464 465 466 467 static int io_flush (lua_State *L) { 468 return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); 469 } 470 471 472 static int f_flush (lua_State *L) { 473 return pushresult(L, fflush(tofile(L)) == 0, NULL); 474 } 475 476 477 static const luaL_Reg iolib[] = { 478 {"close", io_close}, 479 {"flush", io_flush}, 480 {"input", io_input}, 481 {"lines", io_lines}, 482 {"open", io_open}, 483 {"output", io_output}, 484 {"popen", io_popen}, 485 {"read", io_read}, 486 {"tmpfile", io_tmpfile}, 487 {"type", io_type}, 488 {"write", io_write}, 489 {NULL, NULL} 490 }; 491 492 493 static const luaL_Reg flib[] = { 494 {"close", io_close}, 495 {"flush", f_flush}, 496 {"lines", f_lines}, 497 {"read", f_read}, 498 {"seek", f_seek}, 499 {"setvbuf", f_setvbuf}, 500 {"write", f_write}, 501 {"__gc", io_gc}, 502 {"__tostring", io_tostring}, 503 {NULL, NULL} 504 }; 505 506 507 static void createmeta (lua_State *L) { 508 luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */ 509 lua_pushvalue(L, -1); /* push metatable */ 510 lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */ 511 luaL_register(L, NULL, flib); /* file methods */ 512 } 513 514 515 static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) { 516 *newfile(L) = f; 517 if (k > 0) { 518 lua_pushvalue(L, -1); 519 lua_rawseti(L, LUA_ENVIRONINDEX, k); 520 } 521 lua_pushvalue(L, -2); /* copy environment */ 522 lua_setfenv(L, -2); /* set it */ 523 lua_setfield(L, -3, fname); 524 } 525 526 527 static void newfenv (lua_State *L, lua_CFunction cls) { 528 lua_createtable(L, 0, 1); 529 lua_pushcfunction(L, cls); 530 lua_setfield(L, -2, "__close"); 531 } 532 533 534 LUALIB_API int luaopen_io (lua_State *L) { 535 createmeta(L); 536 /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */ 537 newfenv(L, io_fclose); 538 lua_replace(L, LUA_ENVIRONINDEX); 539 /* open library */ 540 luaL_register(L, LUA_IOLIBNAME, iolib); 541 /* create (and set) default files */ 542 newfenv(L, io_noclose); /* close function for default files */ 543 createstdfile(L, stdin, IO_INPUT, "stdin"); 544 createstdfile(L, stdout, IO_OUTPUT, "stdout"); 545 createstdfile(L, stderr, 0, "stderr"); 546 lua_pop(L, 1); /* pop environment for default files */ 547 lua_getfield(L, -1, "popen"); 548 newfenv(L, io_pclose); /* create environment for 'popen' */ 549 lua_setfenv(L, -2); /* set fenv for 'popen' */ 550 lua_pop(L, 1); /* pop 'popen' */ 551 return 1; 552 } 553 554