apps/plugins/lua/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 <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11
  12 #define liolib_c
  13 #define LUA_LIB
  14
  15 #include "lua.h"
  16
  17 #include "lauxlib.h"
  18 #include "lualib.h"
  19 #include "rocklibc.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;
  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, 0);
  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 static int io_type (lua_State *L) {
  55   void *ud;
  56   luaL_checkany(L, 1);
  57   ud = lua_touserdata(L, 1);
  58   lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
  59   if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
  60     lua_pushnil(L);  /* not a file */
  61   else if (*((int *)ud) < 0)
  62     lua_pushliteral(L, "closed file");
  63   else
  64     lua_pushliteral(L, "file");
  65   return 1;
  66 }
  67
  68
  69 static int* tofile (lua_State *L) {
  70   int *f = (int*) luaL_checkudata(L, 1, LUA_FILEHANDLE);
  71   if (*f < 0)
  72     luaL_error(L, "attempt to use a closed file");
  73   return f;
  74 }
  75
  76
  77
  78 /*
  79 ** When creating file handles, always creates a `closed' file handle
  80 ** before opening the actual file; so, if there is a memory error, the
  81 ** file is not left opened.
  82 */
  83 static int* newfile (lua_State *L) {
  84   int *pf = (int *)lua_newuserdata(L, sizeof(int));
  85   *pf = -1;  /* file handle is currently `closed' */
  86   luaL_getmetatable(L, LUA_FILEHANDLE);
  87   lua_setmetatable(L, -2);
  88   return pf;
  89 }
  90
  91
  92 /*
  93 ** function to close regular files
  94 */
  95 static int io_fclose (lua_State *L) {
  96   int *p = tofile(L);
  97   int ok = (rb->close(*p) == 0);
  98   *p = -1;
  99   return pushresult(L, ok, NULL);
 100 }
 101
 102
 103 static inline int aux_close (lua_State *L) {
 104   return io_fclose(L);
 105 }
 106
 107
 108 static int io_close (lua_State *L) {
 109   if (lua_isnone(L, 1))
 110     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
 111   tofile(L);  /* make sure argument is a file */
 112   return aux_close(L);
 113 }
 114
 115
 116 static int io_gc (lua_State *L) {
 117   int f = *(int*) luaL_checkudata(L, 1, LUA_FILEHANDLE);
 118   /* ignore closed files */
 119   if (f >= 0)
 120     aux_close(L);
 121   return 0;
 122 }
 123
 124
 125 static int io_tostring (lua_State *L) {
 126   int f = *(int*) luaL_checkudata(L, 1, LUA_FILEHANDLE);
 127   if (f < 0)
 128     lua_pushliteral(L, "file (closed)");
 129   else
 130     lua_pushfstring(L, "file (%d)", f);
 131   return 1;
 132 }
 133
 134
 135 static int io_open (lua_State *L) {
 136   const char *filename = luaL_checkstring(L, 1);
 137   const char *mode = luaL_optstring(L, 2, "r");
 138   int *pf = newfile(L);
 139   int flags = 0;
 140   if(*(mode+1) == '+') {
 141     flags = O_RDWR;
 142     switch(*mode) {
 143         case 'w':
 144             flags |= O_TRUNC; break;
 145         case 'a':
 146             flags |= O_APPEND; break;
 147     }
 148   }
 149   else {
 150     switch(*mode) {
 151         case 'r':
 152             flags = O_RDONLY; break;
 153         case 'w':
 154             flags = O_WRONLY | O_TRUNC; break;
 155         case 'a':
 156             flags = O_WRONLY | O_APPEND; break;
 157     }
 158   }
 159   if((*mode == 'w' || *mode == 'a') && !rb->file_exists(filename))
 160     flags |= O_CREAT;
 161   *pf = rb->open(filename, flags, 0666);
 162   return (*pf < 0) ? pushresult(L, 0, filename) : 1;
 163 }
 164
 165
 166 static int* getiofile (lua_State *L, int findex) {
 167   int *f;
 168   lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
 169   f = (int *)lua_touserdata(L, -1);
 170   if (f == NULL || *f < 0)
 171     luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
 172   return f;
 173 }
 174
 175
 176 static int g_iofile (lua_State *L, int f, int flags) {
 177   if (!lua_isnoneornil(L, 1)) {
 178     const char *filename = lua_tostring(L, 1);
 179     if (filename) {
 180       int *pf = newfile(L);
 181       *pf = rb->open(filename, flags);
 182       if (*pf < 0)
 183         fileerror(L, 1, filename);
 184     }
 185     else {
 186       tofile(L);  /* check that it's a valid file handle */
 187       lua_pushvalue(L, 1);
 188     }
 189     lua_rawseti(L, LUA_ENVIRONINDEX, f);
 190   }
 191   /* return current value */
 192   lua_rawgeti(L, LUA_ENVIRONINDEX, f);
 193   return 1;
 194 }
 195
 196
 197 static int io_input (lua_State *L) {
 198   return g_iofile(L, IO_INPUT, O_RDONLY);
 199 }
 200
 201
 202 static int io_output (lua_State *L) {
 203   return g_iofile(L, IO_OUTPUT, O_WRONLY);
 204 }
 205
 206
 207 static int io_readline (lua_State *L);
 208
 209
 210 static void aux_lines (lua_State *L, int idx, int toclose) {
 211   lua_pushvalue(L, idx);
 212   lua_pushboolean(L, toclose);  /* close/not close file when finished */
 213   lua_pushcclosure(L, io_readline, 2);
 214 }
 215
 216
 217 static int f_lines (lua_State *L) {
 218   tofile(L);  /* check that it's a valid file handle */
 219   aux_lines(L, 1, 0);
 220   return 1;
 221 }
 222
 223
 224 static int io_lines (lua_State *L) {
 225   if (lua_isnoneornil(L, 1)) {  /* no arguments? */
 226     /* will iterate over default input */
 227     lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
 228     return f_lines(L);
 229   }
 230   else {
 231     const char *filename = luaL_checkstring(L, 1);
 232     int *pf = newfile(L);
 233     *pf = rb->open(filename, O_RDONLY);
 234     if (*pf < 0)
 235       fileerror(L, 1, filename);
 236     aux_lines(L, lua_gettop(L), 1);
 237     return 1;
 238   }
 239 }
 240
 241
 242 /*
 243 ** {======================================================
 244 ** READ
 245 ** =======================================================
 246 */
 247
 248 static int read_number (lua_State *L, int *f) {
 249   lua_Number d;
 250   if (PREFIX(fscanf)(*f, LUA_NUMBER_SCAN, &d) == 1) {
 251     lua_pushnumber(L, d);
 252     return 1;
 253   }
 254   else return 0;  /* read fails */
 255 }
 256
 257
 258 static int test_eof (lua_State *L, int *f) {
 259   ssize_t s = rb->lseek(*f, 0, SEEK_CUR);
 260   lua_pushlstring(L, NULL, 0);
 261   return s != rb->filesize(*f);
 262 }
 263
 264
 265 /* Rockbox already defines read_line() */
 266 static int _read_line (lua_State *L, int *f) {
 267   luaL_Buffer b;
 268   luaL_buffinit(L, &b);
 269   for (;;) {
 270     size_t l;
 271     size_t r;
 272     char *p = luaL_prepbuffer(&b);
 273     r = rb->read_line(*f, p, LUAL_BUFFERSIZE);
 274     l = strlen(p);
 275     if (l == 0 || p[l-1] != '\n')
 276       luaL_addsize(&b, l);
 277     else {
 278       luaL_addsize(&b, l - 1);  /* do not include `eol' */
 279       luaL_pushresult(&b);  /* close buffer */
 280       return 1;  /* read at least an `eol' */
 281     }
 282     if (r < LUAL_BUFFERSIZE) {  /* eof? */
 283       luaL_pushresult(&b);  /* close buffer */
 284       return (lua_objlen(L, -1) > 0);  /* check whether read something */
 285     }
 286   }
 287 }
 288
 289
 290 static int read_chars (lua_State *L, int *f, size_t n) {
 291   size_t rlen;  /* how much to read */
 292   size_t nr;  /* number of chars actually read */
 293   luaL_Buffer b;
 294   luaL_buffinit(L, &b);
 295   rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
 296   do {
 297     char *p = luaL_prepbuffer(&b);
 298     if (rlen > n) rlen = n;  /* cannot read more than asked */
 299     nr = rb->read(*f, p, rlen);
 300     luaL_addsize(&b, nr);
 301     n -= nr;  /* still have to read `n' chars */
 302   } while (n > 0 && nr == rlen);  /* until end of count or eof */
 303   luaL_pushresult(&b);  /* close buffer */
 304   return (n == 0 || lua_objlen(L, -1) > 0);
 305 }
 306
 307
 308 static int g_read (lua_State *L, int *f, int first) {
 309   int nargs = lua_gettop(L) - 1;
 310   int success;
 311   int n;
 312   if (nargs == 0) {  /* no arguments? */
 313     success = _read_line(L, f);
 314     n = first+1;  /* to return 1 result */
 315   }
 316   else {  /* ensure stack space for all results and for auxlib's buffer */
 317     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
 318     success = 1;
 319     for (n = first; nargs-- && success; n++) {
 320       if (lua_type(L, n) == LUA_TNUMBER) {
 321         size_t l = (size_t)lua_tointeger(L, n);
 322         success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
 323       }
 324       else {
 325         const char *p = lua_tostring(L, n);
 326         luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
 327         switch (p[1]) {
 328           case 'n':  /* number */
 329             success = read_number(L, f);
 330             break;
 331           case 'l':  /* line */
 332             success = _read_line(L, f);
 333             break;
 334           case 'a':  /* file */
 335             read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
 336             success = 1; /* always success */
 337             break;
 338           default:
 339             return luaL_argerror(L, n, "invalid format");
 340         }
 341       }
 342     }
 343   }
 344   if (!success) {
 345     lua_pop(L, 1);  /* remove last result */
 346     lua_pushnil(L);  /* push nil instead */
 347   }
 348   return n - first;
 349 }
 350
 351
 352 static int io_read (lua_State *L) {
 353   return g_read(L, getiofile(L, IO_INPUT), 1);
 354 }
 355
 356
 357 static int f_read (lua_State *L) {
 358   return g_read(L, tofile(L), 2);
 359 }
 360
 361
 362 static int io_readline (lua_State *L) {
 363   int *f = (int *) lua_touserdata(L, lua_upvalueindex(1));
 364   int sucess;
 365   if (*f < 0)  /* file is already closed? */
 366     luaL_error(L, "file is already closed");
 367   sucess = _read_line(L, f);
 368   if (sucess) return 1;
 369   else {  /* EOF */
 370     if (lua_toboolean(L, lua_upvalueindex(2))) {  /* generator created file? */
 371       lua_settop(L, 0);
 372       lua_pushvalue(L, lua_upvalueindex(1));
 373       aux_close(L);  /* close it */
 374     }
 375     return 0;
 376   }
 377 }
 378
 379 /* }====================================================== */
 380
 381
 382 static int g_write (lua_State *L, int *f, int arg) {
 383   int nargs = lua_gettop(L) - 1;
 384   int status = 1;
 385   for (; nargs--; arg++) {
 386     if (lua_type(L, arg) == LUA_TNUMBER) {
 387       /* optimization: could be done exactly as for strings */
 388       status = status &&
 389           rb->fdprintf(*f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
 390     }
 391     else {
 392       size_t l;
 393       const char *s = luaL_checklstring(L, arg, &l);
 394       status = status && (rb->write(*f, s, l) == (ssize_t)l);
 395     }
 396   }
 397   return pushresult(L, status, NULL);
 398 }
 399
 400
 401 static int io_write (lua_State *L) {
 402   return g_write(L, getiofile(L, IO_OUTPUT), 1);
 403 }
 404
 405
 406 static int f_write (lua_State *L) {
 407   return g_write(L, tofile(L), 2);
 408 }
 409
 410
 411 static int f_seek (lua_State *L) {
 412   static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
 413   static const char *const modenames[] = {"set", "cur", "end", NULL};
 414   int f = *tofile(L);
 415   int op = luaL_checkoption(L, 2, "cur", modenames);
 416   long offset = luaL_optlong(L, 3, 0);
 417   op = rb->lseek(f, offset, mode[op]);
 418   if (op)
 419     return pushresult(L, 0, NULL);  /* error */
 420   else {
 421     lua_pushinteger(L, rb->lseek(f, 0, SEEK_CUR));
 422     return 1;
 423   }
 424 }
 425
 426
 427 static const luaL_Reg iolib[] = {
 428   {"close", io_close},
 429   {"input", io_input},
 430   {"lines", io_lines},
 431   {"open", io_open},
 432   {"output", io_output},
 433   {"read", io_read},
 434   {"type", io_type},
 435   {"write", io_write},
 436   {NULL, NULL}
 437 };
 438
 439
 440 static const luaL_Reg flib[] = {
 441   {"close", io_close},
 442   {"lines", f_lines},
 443   {"read", f_read},
 444   {"seek", f_seek},
 445   {"write", f_write},
 446   {"__gc", io_gc},
 447   {"__tostring", io_tostring},
 448   {NULL, NULL}
 449 };
 450
 451
 452 static void createmeta (lua_State *L) {
 453   luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
 454   lua_pushvalue(L, -1);  /* push metatable */
 455   lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
 456   luaL_register(L, NULL, flib);  /* file methods */
 457 }
 458
 459
 460 LUALIB_API int luaopen_io (lua_State *L) {
 461   createmeta(L);
 462   lua_replace(L, LUA_ENVIRONINDEX);
 463   /* open library */
 464   luaL_register(L, LUA_IOLIBNAME, iolib);
 465   /* create (and set) default files */
 466   lua_pop(L, 1);  /* pop environment for default files */
 467   return 1;
 468 }