2 ** $Id: liolib.c,v 2.73.1.4 2010/05/14 15:33:51 roberto Exp $
3 ** Standard I/O (and system) library
4 ** See Copyright Notice in lua.h
27 static const char *const fnames[] = {"input", "output"};
30 static int pushresult (lua_State *L, int i, const char *filename) {
31 int en = errno; /* calls to Lua API may change this value */
33 lua_pushboolean(L, 1);
39 lua_pushfstring(L, "%s: %s", filename, strerror(en));
41 lua_pushfstring(L, "%s", strerror(en));
42 lua_pushinteger(L, en);
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));
54 #define tofilep(L) ((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
57 static int io_type (lua_State *L) {
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");
67 lua_pushliteral(L, "file");
72 static FILE *tofile (lua_State *L) {
73 FILE **f = tofilep(L);
75 luaL_error(L, "attempt to use a closed file");
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.
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);
96 ** function to (not) close the standard files stdin, stdout, and stderr
98 static int io_noclose (lua_State *L) {
100 lua_pushliteral(L, "cannot close standard file");
106 ** function to close 'popen' files
108 static int io_pclose (lua_State *L) {
109 FILE **p = tofilep(L);
110 int ok = lua_pclose(L, *p);
112 return pushresult(L, ok, NULL);
117 ** function to close regular files
119 static int io_fclose (lua_State *L) {
120 FILE **p = tofilep(L);
121 int ok = (fclose(*p) == 0);
123 return pushresult(L, ok, NULL);
127 static int aux_close (lua_State *L) {
129 lua_getfield(L, -1, "__close");
130 return (lua_tocfunction(L, -1))(L);
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 */
142 static int io_gc (lua_State *L) {
143 FILE *f = *tofilep(L);
144 /* ignore closed files */
151 static int io_tostring (lua_State *L) {
152 FILE *f = *tofilep(L);
154 lua_pushliteral(L, "file (closed)");
156 lua_pushfstring(L, "file (%p)", f);
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;
171 ** this function has a separated environment, which defines the
172 ** correct __close for 'popen' files
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;
184 static int io_tmpfile (lua_State *L) {
185 FILE **pf = newfile(L);
187 return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
192 static FILE *getiofile (lua_State *L, int findex) {
194 lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
195 f = *(FILE **)lua_touserdata(L, -1);
197 luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
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);
206 FILE **pf = newfile(L);
207 *pf = fopen(filename, mode);
209 fileerror(L, 1, filename);
212 tofile(L); /* check that it's a valid file handle */
215 lua_rawseti(L, LUA_ENVIRONINDEX, f);
217 /* return current value */
218 lua_rawgeti(L, LUA_ENVIRONINDEX, f);
223 static int io_input (lua_State *L) {
224 return g_iofile(L, IO_INPUT, "r");
228 static int io_output (lua_State *L) {
229 return g_iofile(L, IO_OUTPUT, "w");
233 static int io_readline (lua_State *L);
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);
243 static int f_lines (lua_State *L) {
244 tofile(L); /* check that it's a valid file handle */
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);
257 const char *filename = luaL_checkstring(L, 1);
258 FILE **pf = newfile(L);
259 *pf = fopen(filename, "r");
261 fileerror(L, 1, filename);
262 aux_lines(L, lua_gettop(L), 1);
269 ** {======================================================
271 ** =======================================================
275 static int read_number (lua_State *L, FILE *f) {
277 if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
278 lua_pushnumber(L, d);
282 lua_pushnil(L); /* "result" to be removed */
283 return 0; /* read fails */
288 static int test_eof (lua_State *L, FILE *f) {
291 lua_pushlstring(L, NULL, 0);
297 static int read_line (lua_State *L, FILE *f) {
299 luaL_buffinit(L, &b);
302 char *p = luaL_prepbuffer(&b);
303 if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) { /* eof? */
304 luaL_pushresult(&b); /* close buffer */
305 return (lua_objlen(L, -1) > 0); /* check whether read something */
308 if (l == 0 || p[l-1] != '\n')
311 luaL_addsize(&b, l - 1); /* do not include `eol' */
312 luaL_pushresult(&b); /* close buffer */
313 return 1; /* read at least an `eol' */
318 #ifndef SYSLINUX /* Not used */
319 static int read_chars (lua_State *L, FILE *f, size_t n) {
320 size_t rlen; /* how much to read */
321 size_t nr; /* number of chars actually read */
323 luaL_buffinit(L, &b);
324 rlen = LUAL_BUFFERSIZE; /* try to read that much each time */
326 char *p = luaL_prepbuffer(&b);
327 if (rlen > n) rlen = n; /* cannot read more than asked */
328 nr = fread(p, sizeof(char), rlen, f);
329 luaL_addsize(&b, nr);
330 n -= nr; /* still have to read `n' chars */
331 } while (n > 0 && nr == rlen); /* until end of count or eof */
332 luaL_pushresult(&b); /* close buffer */
333 return (n == 0 || lua_objlen(L, -1) > 0);
336 static int g_read (lua_State *L, FILE *f, int first) {
337 int nargs = lua_gettop(L) - 1;
341 if (nargs == 0) { /* no arguments? */
342 success = read_line(L, f);
343 n = first+1; /* to return 1 result */
345 else { /* ensure stack space for all results and for auxlib's buffer */
346 luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
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);
354 const char *p = lua_tostring(L, n);
355 luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
357 case 'n': /* number */
358 success = read_number(L, f);
361 success = read_line(L, f);
364 read_chars(L, f, ~((size_t)0)); /* read MAX_SIZE_T chars */
365 success = 1; /* always success */
368 return luaL_argerror(L, n, "invalid format");
374 return pushresult(L, 0, NULL);
376 lua_pop(L, 1); /* remove last result */
377 lua_pushnil(L); /* push nil instead */
383 static int io_read (lua_State *L) {
384 return g_read(L, getiofile(L, IO_INPUT), 1);
388 static int f_read (lua_State *L) {
389 return g_read(L, tofile(L), 2);
394 static int io_readline (lua_State *L) {
395 FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
397 if (f == NULL) /* file is already closed? */
398 luaL_error(L, "file is already closed");
399 sucess = read_line(L, f);
401 return luaL_error(L, "%s", strerror(errno));
402 if (sucess) return 1;
404 if (lua_toboolean(L, lua_upvalueindex(2))) { /* generator created file? */
406 lua_pushvalue(L, lua_upvalueindex(1));
407 aux_close(L); /* close it */
413 /* }====================================================== */
416 static int g_write (lua_State *L, FILE *f, int arg) {
417 int nargs = lua_gettop(L) - 1;
419 for (; nargs--; arg++) {
420 if (lua_type(L, arg) == LUA_TNUMBER) {
421 /* optimization: could be done exactly as for strings */
423 fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
427 const char *s = luaL_checklstring(L, arg, &l);
428 status = status && (fwrite(s, sizeof(char), l, f) == l);
431 return pushresult(L, status, NULL);
435 static int io_write (lua_State *L) {
436 return g_write(L, getiofile(L, IO_OUTPUT), 1);
440 static int f_write (lua_State *L) {
441 return g_write(L, tofile(L), 2);
445 static int f_seek (lua_State *L) {
446 static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
447 static const char *const modenames[] = {"set", "cur", "end", NULL};
449 int op = luaL_checkoption(L, 2, "cur", modenames);
450 long offset = luaL_optlong(L, 3, 0);
451 op = fseek(f, offset, mode[op]);
453 return pushresult(L, 0, NULL); /* error */
455 lua_pushinteger(L, ftell(f));
461 static int f_setvbuf (lua_State *L) {
462 static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
463 static const char *const modenames[] = {"no", "full", "line", NULL};
465 int op = luaL_checkoption(L, 2, NULL, modenames);
466 lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
467 int res = setvbuf(f, NULL, mode[op], sz);
468 return pushresult(L, res == 0, NULL);
473 static int io_flush (lua_State *L) {
474 return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
478 static int f_flush (lua_State *L) {
479 return pushresult(L, fflush(tofile(L)) == 0, NULL);
483 static const luaL_Reg iolib[] = {
489 {"output", io_output},
493 {"tmpfile", io_tmpfile},
501 static const luaL_Reg flib[] = {
508 {"setvbuf", f_setvbuf},
512 {"__tostring", io_tostring},
517 static void createmeta (lua_State *L) {
518 luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */
519 lua_pushvalue(L, -1); /* push metatable */
520 lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */
521 luaL_register(L, NULL, flib); /* file methods */
525 static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
528 lua_pushvalue(L, -1);
529 lua_rawseti(L, LUA_ENVIRONINDEX, k);
531 lua_pushvalue(L, -2); /* copy environment */
532 lua_setfenv(L, -2); /* set it */
533 lua_setfield(L, -3, fname);
537 static void newfenv (lua_State *L, lua_CFunction cls) {
538 lua_createtable(L, 0, 1);
539 lua_pushcfunction(L, cls);
540 lua_setfield(L, -2, "__close");
544 LUALIB_API int luaopen_io (lua_State *L) {
546 /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
547 newfenv(L, io_fclose);
548 lua_replace(L, LUA_ENVIRONINDEX);
550 luaL_register(L, LUA_IOLIBNAME, iolib);
551 /* create (and set) default files */
552 newfenv(L, io_noclose); /* close function for default files */
553 createstdfile(L, stdin, IO_INPUT, "stdin");
554 createstdfile(L, stdout, IO_OUTPUT, "stdout");
555 createstdfile(L, stderr, 0, "stderr");
556 lua_pop(L, 1); /* pop environment for default files */
557 lua_getfield(L, -1, "popen");
558 newfenv(L, io_pclose); /* create environment for 'popen' */
559 lua_setfenv(L, -2); /* set fenv for 'popen' */
560 lua_pop(L, 1); /* pop 'popen' */