PageRenderTime 107ms CodeModel.GetById 30ms app.highlight 56ms RepoModel.GetById 14ms app.codeStats 0ms

/script_binding/lua/lua/liolib.c

http://ftk.googlecode.com/
C | 553 lines | 411 code | 106 blank | 36 comment | 82 complexity | 0b6389d39a7c1fe8ff286919dcac334d MD5 | raw file
  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
 27static const char *const fnames[] = {"input", "output"};
 28
 29
 30static 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
 48static 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
 57static 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
 72static 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*/
 86static 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*/
 98static 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*/
108static 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*/
119static 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
127static 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
134static 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
142static 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
151static 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
161static 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*/
174static 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
183static 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
190static 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
200static 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
221static int io_input (lua_State *L) {
222  return g_iofile(L, IO_INPUT, "r");
223}
224
225
226static int io_output (lua_State *L) {
227  return g_iofile(L, IO_OUTPUT, "w");
228}
229
230
231static int io_readline (lua_State *L);
232
233
234static 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
241static 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
248static 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
273static 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
283static 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
291static 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
313static 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
331static 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
378static int io_read (lua_State *L) {
379  return g_read(L, getiofile(L, IO_INPUT), 1);
380}
381
382
383static int f_read (lua_State *L) {
384  return g_read(L, tofile(L), 2);
385}
386
387
388static 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
410static 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
429static int io_write (lua_State *L) {
430  return g_write(L, getiofile(L, IO_OUTPUT), 1);
431}
432
433
434static int f_write (lua_State *L) {
435  return g_write(L, tofile(L), 2);
436}
437
438
439static 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
455static 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
467static int io_flush (lua_State *L) {
468  return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
469}
470
471
472static int f_flush (lua_State *L) {
473  return pushresult(L, fflush(tofile(L)) == 0, NULL);
474}
475
476
477static 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
493static 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
507static 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
515static 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
527static 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
534LUALIB_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