src/lib_io.c

   1 /*
   2 ** I/O library.
   3 ** Copyright (C) 2005-2025 Mike Pall. See Copyright Notice in luajit.h
   4 **
   5 ** Major portions taken verbatim or adapted from the Lua interpreter.
   6 ** Copyright (C) 1994-2011 Lua.org, PUC-Rio. See Copyright Notice in lua.h
   7 */
   8
   9 #include <errno.h>
  10 #include <stdio.h>
  11
  12 #define lib_io_c
  13 #define LUA_LIB
  14
  15 #include "lua.h"
  16 #include "lauxlib.h"
  17 #include "lualib.h"
  18
  19 #include "lj_obj.h"
  20 #include "lj_gc.h"
  21 #include "lj_err.h"
  22 #include "lj_buf.h"
  23 #include "lj_str.h"
  24 #include "lj_state.h"
  25 #include "lj_strfmt.h"
  26 #include "lj_ff.h"
  27 #include "lj_lib.h"
  28
  29 /* Userdata payload for I/O file. */
  30 typedef struct IOFileUD {
  31   FILE *fp;             /* File handle. */
  32   uint32_t type;        /* File type. */
  33 } IOFileUD;
  34
  35 #define IOFILE_TYPE_FILE        0       /* Regular file. */
  36 #define IOFILE_TYPE_PIPE        1       /* Pipe. */
  37 #define IOFILE_TYPE_STDF        2       /* Standard file handle. */
  38 #define IOFILE_TYPE_MASK        3
  39
  40 #define IOFILE_FLAG_CLOSE       4       /* Close after io.lines() iterator. */
  41
  42 #define IOSTDF_UD(L, id)        (&gcref(G(L)->gcroot[(id)])->ud)
  43 #define IOSTDF_IOF(L, id)       ((IOFileUD *)uddata(IOSTDF_UD(L, (id))))
  44
  45 /* -- Open/close helpers -------------------------------------------------- */
  46
  47 static IOFileUD *io_tofilep(lua_State *L)
  48 {
  49   if (!(L->base < L->top && tvisudata(L->base) &&
  50         udataV(L->base)->udtype == UDTYPE_IO_FILE))
  51     lj_err_argtype(L, 1, "FILE*");
  52   return (IOFileUD *)uddata(udataV(L->base));
  53 }
  54
  55 static IOFileUD *io_tofile(lua_State *L)
  56 {
  57   IOFileUD *iof = io_tofilep(L);
  58   if (iof->fp == NULL)
  59     lj_err_caller(L, LJ_ERR_IOCLFL);
  60   return iof;
  61 }
  62
  63 static IOFileUD *io_stdfile(lua_State *L, ptrdiff_t id)
  64 {
  65   IOFileUD *iof = IOSTDF_IOF(L, id);
  66   if (iof->fp == NULL)
  67     lj_err_caller(L, LJ_ERR_IOSTDCL);
  68   return iof;
  69 }
  70
  71 static IOFileUD *io_file_new(lua_State *L)
  72 {
  73   IOFileUD *iof = (IOFileUD *)lua_newuserdata(L, sizeof(IOFileUD));
  74   GCudata *ud = udataV(L->top-1);
  75   ud->udtype = UDTYPE_IO_FILE;
  76   /* NOBARRIER: The GCudata is new (marked white). */
  77   setgcrefr(ud->metatable, curr_func(L)->c.env);
  78   iof->fp = NULL;
  79   iof->type = IOFILE_TYPE_FILE;
  80   return iof;
  81 }
  82
  83 static IOFileUD *io_file_open(lua_State *L, const char *mode)
  84 {
  85   const char *fname = strdata(lj_lib_checkstr(L, 1));
  86   IOFileUD *iof = io_file_new(L);
  87   iof->fp = fopen(fname, mode);
  88   if (iof->fp == NULL)
  89     luaL_argerror(L, 1, lj_strfmt_pushf(L, "%s: %s", fname, strerror(errno)));
  90   return iof;
  91 }
  92
  93 static int io_file_close(lua_State *L, IOFileUD *iof)
  94 {
  95   int ok;
  96   if ((iof->type & IOFILE_TYPE_MASK) == IOFILE_TYPE_FILE) {
  97     ok = (fclose(iof->fp) == 0);
  98   } else if ((iof->type & IOFILE_TYPE_MASK) == IOFILE_TYPE_PIPE) {
  99     int stat = -1;
 100 #if LJ_TARGET_POSIX
 101     stat = pclose(iof->fp);
 102 #elif LJ_TARGET_WINDOWS && !LJ_TARGET_XBOXONE && !LJ_TARGET_UWP
 103     stat = _pclose(iof->fp);
 104 #endif
 105 #if LJ_52
 106     iof->fp = NULL;
 107     return luaL_execresult(L, stat);
 108 #else
 109     ok = (stat != -1);
 110 #endif
 111   } else {
 112     lj_assertL((iof->type & IOFILE_TYPE_MASK) == IOFILE_TYPE_STDF,
 113                "close of unknown FILE* type");
 114     setnilV(L->top++);
 115     lua_pushliteral(L, "cannot close standard file");
 116     return 2;
 117   }
 118   iof->fp = NULL;
 119   return luaL_fileresult(L, ok, NULL);
 120 }
 121
 122 /* -- Read/write helpers -------------------------------------------------- */
 123
 124 static int io_file_readnum(lua_State *L, FILE *fp)
 125 {
 126   lua_Number d;
 127   if (fscanf(fp, LUA_NUMBER_SCAN, &d) == 1) {
 128     if (LJ_DUALNUM) {
 129       int32_t i = lj_num2int(d);
 130       if (d == (lua_Number)i && !tvismzero((cTValue *)&d)) {
 131         setintV(L->top++, i);
 132         return 1;
 133       }
 134     }
 135     setnumV(L->top++, d);
 136     return 1;
 137   } else {
 138     setnilV(L->top++);
 139     return 0;
 140   }
 141 }
 142
 143 static int io_file_readline(lua_State *L, FILE *fp, MSize chop)
 144 {
 145   MSize m = LUAL_BUFFERSIZE, n = 0, ok = 0;
 146   char *buf;
 147   for (;;) {
 148     buf = lj_buf_tmp(L, m);
 149     if (fgets(buf+n, m-n, fp) == NULL) break;
 150     n += (MSize)strlen(buf+n);
 151     ok |= n;
 152     if (n && buf[n-1] == '\n') { n -= chop; break; }
 153     if (n >= m - 64) m += m;
 154   }
 155   setstrV(L, L->top++, lj_str_new(L, buf, (size_t)n));
 156   lj_gc_check(L);
 157   return (int)ok;
 158 }
 159
 160 static void io_file_readall(lua_State *L, FILE *fp)
 161 {
 162   MSize m, n;
 163   for (m = LUAL_BUFFERSIZE, n = 0; ; m += m) {
 164     char *buf = lj_buf_tmp(L, m);
 165     n += (MSize)fread(buf+n, 1, m-n, fp);
 166     if (n != m) {
 167       setstrV(L, L->top++, lj_str_new(L, buf, (size_t)n));
 168       lj_gc_check(L);
 169       return;
 170     }
 171   }
 172 }
 173
 174 static int io_file_readlen(lua_State *L, FILE *fp, MSize m)
 175 {
 176   if (m) {
 177     char *buf = lj_buf_tmp(L, m);
 178     MSize n = (MSize)fread(buf, 1, m, fp);
 179     setstrV(L, L->top++, lj_str_new(L, buf, (size_t)n));
 180     lj_gc_check(L);
 181     return n > 0;
 182   } else {
 183     int c = getc(fp);
 184     ungetc(c, fp);
 185     setstrV(L, L->top++, &G(L)->strempty);
 186     return (c != EOF);
 187   }
 188 }
 189
 190 static int io_file_read(lua_State *L, IOFileUD *iof, int start)
 191 {
 192   FILE *fp = iof->fp;
 193   int ok, n, nargs = (int)(L->top - L->base) - start;
 194   clearerr(fp);
 195   if (nargs == 0) {
 196     ok = io_file_readline(L, fp, 1);
 197     n = start+1;  /* Return 1 result. */
 198   } else {
 199     /* The results plus the buffers go on top of the args. */
 200     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
 201     ok = 1;
 202     for (n = start; nargs-- && ok; n++) {
 203       if (tvisstr(L->base+n)) {
 204         const char *p = strVdata(L->base+n);
 205         if (p[0] == '*') p++;
 206         if (p[0] == 'n')
 207           ok = io_file_readnum(L, fp);
 208         else if ((p[0] & ~0x20) == 'L')
 209           ok = io_file_readline(L, fp, (p[0] == 'l'));
 210         else if (p[0] == 'a')
 211           io_file_readall(L, fp);
 212         else
 213           lj_err_arg(L, n+1, LJ_ERR_INVFMT);
 214       } else if (tvisnumber(L->base+n)) {
 215         ok = io_file_readlen(L, fp, (MSize)lj_lib_checkint(L, n+1));
 216       } else {
 217         lj_err_arg(L, n+1, LJ_ERR_INVOPT);
 218       }
 219     }
 220   }
 221   if (ferror(fp))
 222     return luaL_fileresult(L, 0, NULL);
 223   if (!ok)
 224     setnilV(L->top-1);  /* Replace last result with nil. */
 225   return n - start;
 226 }
 227
 228 static int io_file_write(lua_State *L, IOFileUD *iof, int start)
 229 {
 230   FILE *fp = iof->fp;
 231   cTValue *tv;
 232   int status = 1;
 233   for (tv = L->base+start; tv < L->top; tv++) {
 234     MSize len;
 235     const char *p = lj_strfmt_wstrnum(L, tv, &len);
 236     if (!p)
 237       lj_err_argt(L, (int)(tv - L->base) + 1, LUA_TSTRING);
 238     status = status && (fwrite(p, 1, len, fp) == len);
 239   }
 240   if (LJ_52 && status) {
 241     L->top = L->base+1;
 242     if (start == 0)
 243       setudataV(L, L->base, IOSTDF_UD(L, GCROOT_IO_OUTPUT));
 244     return 1;
 245   }
 246   return luaL_fileresult(L, status, NULL);
 247 }
 248
 249 static int io_file_iter(lua_State *L)
 250 {
 251   GCfunc *fn = curr_func(L);
 252   IOFileUD *iof = uddata(udataV(&fn->c.upvalue[0]));
 253   int n = fn->c.nupvalues - 1;
 254   if (iof->fp == NULL)
 255     lj_err_caller(L, LJ_ERR_IOCLFL);
 256   L->top = L->base;
 257   if (n) {  /* Copy upvalues with options to stack. */
 258     lj_state_checkstack(L, (MSize)n);
 259     memcpy(L->top, &fn->c.upvalue[1], n*sizeof(TValue));
 260     L->top += n;
 261   }
 262   n = io_file_read(L, iof, 0);
 263   if (ferror(iof->fp))
 264     lj_err_callermsg(L, strVdata(L->top-2));
 265   if (tvisnil(L->base) && (iof->type & IOFILE_FLAG_CLOSE)) {
 266     io_file_close(L, iof);  /* Return values are ignored. */
 267     return 0;
 268   }
 269   return n;
 270 }
 271
 272 static int io_file_lines(lua_State *L)
 273 {
 274   int n = (int)(L->top - L->base);
 275   if (n > LJ_MAX_UPVAL)
 276     lj_err_caller(L, LJ_ERR_UNPACK);
 277   lua_pushcclosure(L, io_file_iter, n);
 278   return 1;
 279 }
 280
 281 /* -- I/O file methods ---------------------------------------------------- */
 282
 283 #define LJLIB_MODULE_io_method
 284
 285 LJLIB_CF(io_method_close)
 286 {
 287   IOFileUD *iof;
 288   if (L->base < L->top) {
 289     iof = io_tofile(L);
 290   } else {
 291     iof = IOSTDF_IOF(L, GCROOT_IO_OUTPUT);
 292     if (iof->fp == NULL)
 293       lj_err_caller(L, LJ_ERR_IOCLFL);
 294   }
 295   return io_file_close(L, iof);
 296 }
 297
 298 LJLIB_CF(io_method_read)
 299 {
 300   return io_file_read(L, io_tofile(L), 1);
 301 }
 302
 303 LJLIB_CF(io_method_write)               LJLIB_REC(io_write 0)
 304 {
 305   return io_file_write(L, io_tofile(L), 1);
 306 }
 307
 308 LJLIB_CF(io_method_flush)               LJLIB_REC(io_flush 0)
 309 {
 310   return luaL_fileresult(L, fflush(io_tofile(L)->fp) == 0, NULL);
 311 }
 312
 313 #if LJ_32 && defined(__ANDROID__) && __ANDROID_API__ < 24
 314 /* The Android NDK is such an unmatched marvel of engineering. */
 315 extern int fseeko32(FILE *, long int, int) __asm__("fseeko");
 316 extern long int ftello32(FILE *) __asm__("ftello");
 317 #define fseeko(fp, pos, whence) (fseeko32((fp), (pos), (whence)))
 318 #define ftello(fp)              (ftello32((fp)))
 319 #endif
 320
 321 LJLIB_CF(io_method_seek)
 322 {
 323   FILE *fp = io_tofile(L)->fp;
 324   int opt = lj_lib_checkopt(L, 2, 1, "\3set\3cur\3end");
 325   int64_t ofs = 0;
 326   cTValue *o;
 327   int res;
 328   if (opt == 0) opt = SEEK_SET;
 329   else if (opt == 1) opt = SEEK_CUR;
 330   else if (opt == 2) opt = SEEK_END;
 331   o = L->base+2;
 332   if (o < L->top) {
 333     if (tvisint(o))
 334       ofs = (int64_t)intV(o);
 335     else if (tvisnum(o))
 336       ofs = (int64_t)numV(o);
 337     else if (!tvisnil(o))
 338       lj_err_argt(L, 3, LUA_TNUMBER);
 339   }
 340 #if LJ_TARGET_POSIX
 341   res = fseeko(fp, ofs, opt);
 342 #elif _MSC_VER >= 1400
 343   res = _fseeki64(fp, ofs, opt);
 344 #elif defined(__MINGW32__)
 345   res = fseeko64(fp, ofs, opt);
 346 #else
 347   res = fseek(fp, (long)ofs, opt);
 348 #endif
 349   if (res)
 350     return luaL_fileresult(L, 0, NULL);
 351 #if LJ_TARGET_POSIX
 352   ofs = ftello(fp);
 353 #elif _MSC_VER >= 1400
 354   ofs = _ftelli64(fp);
 355 #elif defined(__MINGW32__)
 356   ofs = ftello64(fp);
 357 #else
 358   ofs = (int64_t)ftell(fp);
 359 #endif
 360   setint64V(L->top-1, ofs);
 361   return 1;
 362 }
 363
 364 LJLIB_CF(io_method_setvbuf)
 365 {
 366   FILE *fp = io_tofile(L)->fp;
 367   int opt = lj_lib_checkopt(L, 2, -1, "\4full\4line\2no");
 368   size_t sz = (size_t)lj_lib_optint(L, 3, LUAL_BUFFERSIZE);
 369   if (opt == 0) opt = _IOFBF;
 370   else if (opt == 1) opt = _IOLBF;
 371   else if (opt == 2) opt = _IONBF;
 372   return luaL_fileresult(L, setvbuf(fp, NULL, opt, sz) == 0, NULL);
 373 }
 374
 375 LJLIB_CF(io_method_lines)
 376 {
 377   io_tofile(L);
 378   return io_file_lines(L);
 379 }
 380
 381 LJLIB_CF(io_method___gc)
 382 {
 383   IOFileUD *iof = io_tofilep(L);
 384   if (iof->fp != NULL && (iof->type & IOFILE_TYPE_MASK) != IOFILE_TYPE_STDF)
 385     io_file_close(L, iof);
 386   return 0;
 387 }
 388
 389 LJLIB_CF(io_method___tostring)
 390 {
 391   IOFileUD *iof = io_tofilep(L);
 392   if (iof->fp != NULL)
 393     lua_pushfstring(L, "file (%p)", iof->fp);
 394   else
 395     lua_pushliteral(L, "file (closed)");
 396   return 1;
 397 }
 398
 399 LJLIB_PUSH(top-1) LJLIB_SET(__index)
 400
 401 #include "lj_libdef.h"
 402
 403 /* -- I/O library functions ----------------------------------------------- */
 404
 405 #define LJLIB_MODULE_io
 406
 407 LJLIB_PUSH(top-2) LJLIB_SET(!)  /* Set environment. */
 408
 409 LJLIB_CF(io_open)
 410 {
 411   const char *fname = strdata(lj_lib_checkstr(L, 1));
 412   GCstr *s = lj_lib_optstr(L, 2);
 413   const char *mode = s ? strdata(s) : "r";
 414   IOFileUD *iof = io_file_new(L);
 415   iof->fp = fopen(fname, mode);
 416   return iof->fp != NULL ? 1 : luaL_fileresult(L, 0, fname);
 417 }
 418
 419 LJLIB_CF(io_popen)
 420 {
 421 #if LJ_TARGET_POSIX || (LJ_TARGET_WINDOWS && !LJ_TARGET_XBOXONE && !LJ_TARGET_UWP)
 422   const char *fname = strdata(lj_lib_checkstr(L, 1));
 423   GCstr *s = lj_lib_optstr(L, 2);
 424   const char *mode = s ? strdata(s) : "r";
 425   IOFileUD *iof = io_file_new(L);
 426   iof->type = IOFILE_TYPE_PIPE;
 427 #if LJ_TARGET_POSIX
 428   fflush(NULL);
 429   iof->fp = popen(fname, mode);
 430 #else
 431   iof->fp = _popen(fname, mode);
 432 #endif
 433   return iof->fp != NULL ? 1 : luaL_fileresult(L, 0, fname);
 434 #else
 435   return luaL_error(L, LUA_QL("popen") " not supported");
 436 #endif
 437 }
 438
 439 LJLIB_CF(io_tmpfile)
 440 {
 441   IOFileUD *iof = io_file_new(L);
 442 #if LJ_TARGET_PS3 || LJ_TARGET_PS4 || LJ_TARGET_PS5 || LJ_TARGET_PSVITA || LJ_TARGET_NX
 443   iof->fp = NULL; errno = ENOSYS;
 444 #else
 445   iof->fp = tmpfile();
 446 #endif
 447   return iof->fp != NULL ? 1 : luaL_fileresult(L, 0, NULL);
 448 }
 449
 450 LJLIB_CF(io_close)
 451 {
 452   return lj_cf_io_method_close(L);
 453 }
 454
 455 LJLIB_CF(io_read)
 456 {
 457   return io_file_read(L, io_stdfile(L, GCROOT_IO_INPUT), 0);
 458 }
 459
 460 LJLIB_CF(io_write)              LJLIB_REC(io_write GCROOT_IO_OUTPUT)
 461 {
 462   return io_file_write(L, io_stdfile(L, GCROOT_IO_OUTPUT), 0);
 463 }
 464
 465 LJLIB_CF(io_flush)              LJLIB_REC(io_flush GCROOT_IO_OUTPUT)
 466 {
 467   return luaL_fileresult(L, fflush(io_stdfile(L, GCROOT_IO_OUTPUT)->fp) == 0, NULL);
 468 }
 469
 470 static int io_std_getset(lua_State *L, ptrdiff_t id, const char *mode)
 471 {
 472   if (L->base < L->top && !tvisnil(L->base)) {
 473     if (tvisudata(L->base)) {
 474       io_tofile(L);
 475       L->top = L->base+1;
 476     } else {
 477       io_file_open(L, mode);
 478     }
 479     /* NOBARRIER: The standard I/O handles are GC roots. */
 480     setgcref(G(L)->gcroot[id], gcV(L->top-1));
 481   } else {
 482     setudataV(L, L->top++, IOSTDF_UD(L, id));
 483   }
 484   return 1;
 485 }
 486
 487 LJLIB_CF(io_input)
 488 {
 489   return io_std_getset(L, GCROOT_IO_INPUT, "r");
 490 }
 491
 492 LJLIB_CF(io_output)
 493 {
 494   return io_std_getset(L, GCROOT_IO_OUTPUT, "w");
 495 }
 496
 497 LJLIB_CF(io_lines)
 498 {
 499   if (L->base == L->top) setnilV(L->top++);
 500   if (!tvisnil(L->base)) {  /* io.lines(fname) */
 501     IOFileUD *iof = io_file_open(L, "r");
 502     iof->type = IOFILE_TYPE_FILE|IOFILE_FLAG_CLOSE;
 503     L->top--;
 504     setudataV(L, L->base, udataV(L->top));
 505   } else {  /* io.lines() iterates over stdin. */
 506     setudataV(L, L->base, IOSTDF_UD(L, GCROOT_IO_INPUT));
 507   }
 508   return io_file_lines(L);
 509 }
 510
 511 LJLIB_CF(io_type)
 512 {
 513   cTValue *o = lj_lib_checkany(L, 1);
 514   if (!(tvisudata(o) && udataV(o)->udtype == UDTYPE_IO_FILE))
 515     setnilV(L->top++);
 516   else if (((IOFileUD *)uddata(udataV(o)))->fp != NULL)
 517     lua_pushliteral(L, "file");
 518   else
 519     lua_pushliteral(L, "closed file");
 520   return 1;
 521 }
 522
 523 #include "lj_libdef.h"
 524
 525 /* ------------------------------------------------------------------------ */
 526
 527 static GCobj *io_std_new(lua_State *L, FILE *fp, const char *name)
 528 {
 529   IOFileUD *iof = (IOFileUD *)lua_newuserdata(L, sizeof(IOFileUD));
 530   GCudata *ud = udataV(L->top-1);
 531   ud->udtype = UDTYPE_IO_FILE;
 532   /* NOBARRIER: The GCudata is new (marked white). */
 533   setgcref(ud->metatable, gcV(L->top-3));
 534   iof->fp = fp;
 535   iof->type = IOFILE_TYPE_STDF;
 536   lua_setfield(L, -2, name);
 537   return obj2gco(ud);
 538 }
 539
 540 LUALIB_API int luaopen_io(lua_State *L)
 541 {
 542   LJ_LIB_REG(L, NULL, io_method);
 543   copyTV(L, L->top, L->top-1); L->top++;
 544   lua_setfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
 545   LJ_LIB_REG(L, LUA_IOLIBNAME, io);
 546   setgcref(G(L)->gcroot[GCROOT_IO_INPUT], io_std_new(L, stdin, "stdin"));
 547   setgcref(G(L)->gcroot[GCROOT_IO_OUTPUT], io_std_new(L, stdout, "stdout"));
 548   io_std_new(L, stderr, "stderr");
 549   return 1;
 550 }
 551