deps/lua/src/liolib.c

/*
** $Id: liolib.c,v 2.73.1.3 2008/01/18 17:47:43 roberto Exp $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/


#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define liolib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"


#define IO_INPUT	1
#define IO_OUTPUT	2


static const char *const fnames[] = {"input", "output"};


static int pushresult (lua_State *L, int i, const char *filename) {
  int en = errno;  /* calls to Lua API may change this value */
  if (i) {
    lua_pushboolean(L, 1);
    return 1;
  }
  else {
    lua_pushnil(L);
    if (filename)
      lua_pushfstring(L, "%s: %s", filename, strerror(en));
    else
      lua_pushfstring(L, "%s", strerror(en));
    lua_pushinteger(L, en);
    return 3;
  }
}


static void fileerror (lua_State *L, int arg, const char *filename) {
  lua_pushfstring(L, "%s: %s", filename, strerror(errno));
  luaL_argerror(L, arg, lua_tostring(L, -1));
}


#define tofilep(L)	((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))


static int io_type (lua_State *L) {
  void *ud;
  luaL_checkany(L, 1);
  ud = lua_touserdata(L, 1);
  lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
  if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
    lua_pushnil(L);  /* not a file */
  else if (*((FILE **)ud) == NULL)
    lua_pushliteral(L, "closed file");
  else
    lua_pushliteral(L, "file");
  return 1;
}


static FILE *tofile (lua_State *L) {
  FILE **f = tofilep(L);
  if (*f == NULL)
    luaL_error(L, "attempt to use a closed file");
  return *f;
}


/*
** When creating file handles, always creates a `closed' file handle
** before opening the actual file; so, if there is a memory error, the
** file is not left opened.
*/
static FILE **newfile (lua_State *L) {
  FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
  *pf = NULL;  /* file handle is currently `closed' */
  luaL_getmetatable(L, LUA_FILEHANDLE);
  lua_setmetatable(L, -2);
  return pf;
}


/*
** function to (not) close the standard files stdin, stdout, and stderr
*/
static int io_noclose (lua_State *L) {
  lua_pushnil(L);
  lua_pushliteral(L, "cannot close standard file");
  return 2;
}


/*
** function to close 'popen' files
*/
static int io_pclose (lua_State *L) {
  FILE **p = tofilep(L);
  int ok = lua_pclose(L, *p);
  *p = NULL;
  return pushresult(L, ok, NULL);
}


/*
** function to close regular files
*/
static int io_fclose (lua_State *L) {
  FILE **p = tofilep(L);
  int ok = (fclose(*p) == 0);
  *p = NULL;
  return pushresult(L, ok, NULL);
}


static int aux_close (lua_State *L) {
  lua_getfenv(L, 1);
  lua_getfield(L, -1, "__close");
  return (lua_tocfunction(L, -1))(L);
}


static int io_close (lua_State *L) {
  if (lua_isnone(L, 1))
    lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);
  tofile(L);  /* make sure argument is a file */
  return aux_close(L);
}


static int io_gc (lua_State *L) {
  FILE *f = *tofilep(L);
  /* ignore closed files */
  if (f != NULL)
    aux_close(L);
  return 0;
}


static int io_tostring (lua_State *L) {
  FILE *f = *tofilep(L);
  if (f == NULL)
    lua_pushliteral(L, "file (closed)");
  else
    lua_pushfstring(L, "file (%p)", f);
  return 1;
}


static int io_open (lua_State *L) {
  const char *filename = luaL_checkstring(L, 1);
  const char *mode = luaL_optstring(L, 2, "r");
  FILE **pf = newfile(L);
  *pf = fopen(filename, mode);
  return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
}


/*
** this function has a separated environment, which defines the
** correct __close for 'popen' files
*/
static int io_popen (lua_State *L) {
  const char *filename = luaL_checkstring(L, 1);
  const char *mode = luaL_optstring(L, 2, "r");
  FILE **pf = newfile(L);
  *pf = lua_popen(L, filename, mode);
  return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
}


static int io_tmpfile (lua_State *L) {
  FILE **pf = newfile(L);
  *pf = tmpfile();
  return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
}


static FILE *getiofile (lua_State *L, int findex) {
  FILE *f;
  lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
  f = *(FILE **)lua_touserdata(L, -1);
  if (f == NULL)
    luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
  return f;
}


static int g_iofile (lua_State *L, int f, const char *mode) {
  if (!lua_isnoneornil(L, 1)) {
    const char *filename = lua_tostring(L, 1);
    if (filename) {
      FILE **pf = newfile(L);
      *pf = fopen(filename, mode);
      if (*pf == NULL)
        fileerror(L, 1, filename);
    }
    else {
      tofile(L);  /* check that it's a valid file handle */
      lua_pushvalue(L, 1);
    }
    lua_rawseti(L, LUA_ENVIRONINDEX, f);
  }
  /* return current value */
  lua_rawgeti(L, LUA_ENVIRONINDEX, f);
  return 1;
}


static int io_input (lua_State *L) {
  return g_iofile(L, IO_INPUT, "r");
}


static int io_output (lua_State *L) {
  return g_iofile(L, IO_OUTPUT, "w");
}


static int io_readline (lua_State *L);


static void aux_lines (lua_State *L, int idx, int toclose) {
  lua_pushvalue(L, idx);
  lua_pushboolean(L, toclose);  /* close/not close file when finished */
  lua_pushcclosure(L, io_readline, 2);
}


static int f_lines (lua_State *L) {
  tofile(L);  /* check that it's a valid file handle */
  aux_lines(L, 1, 0);
  return 1;
}


static int io_lines (lua_State *L) {
  if (lua_isnoneornil(L, 1)) {  /* no arguments? */
    /* will iterate over default input */
    lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
    return f_lines(L);
  }
  else {
    const char *filename = luaL_checkstring(L, 1);
    FILE **pf = newfile(L);
    *pf = fopen(filename, "r");
    if (*pf == NULL)
      fileerror(L, 1, filename);
    aux_lines(L, lua_gettop(L), 1);
    return 1;
  }
}


/*
** {======================================================
** READ
** =======================================================
*/


static int read_number (lua_State *L, FILE *f) {
  lua_Number d;
  if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1) {
    lua_pushnumber(L, d);
    return 1;
  }
  else return 0;  /* read fails */
}


static int test_eof (lua_State *L, FILE *f) {
  int c = getc(f);
  ungetc(c, f);
  lua_pushlstring(L, NULL, 0);
  return (c != EOF);
}


static int read_line (lua_State *L, FILE *f) {
  luaL_Buffer b;
  luaL_buffinit(L, &b);
  for (;;) {
    size_t l;
    char *p = luaL_prepbuffer(&b);
    if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) {  /* eof? */
      luaL_pushresult(&b);  /* close buffer */
      return (lua_objlen(L, -1) > 0);  /* check whether read something */
    }
    l = strlen(p);
    if (l == 0 || p[l-1] != '\n')
      luaL_addsize(&b, l);
    else {
      luaL_addsize(&b, l - 1);  /* do not include `eol' */
      luaL_pushresult(&b);  /* close buffer */
      return 1;  /* read at least an `eol' */
    }
  }
}


static int read_chars (lua_State *L, FILE *f, size_t n) {
  size_t rlen;  /* how much to read */
  size_t nr;  /* number of chars actually read */
  luaL_Buffer b;
  luaL_buffinit(L, &b);
  rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
  do {
    char *p = luaL_prepbuffer(&b);
    if (rlen > n) rlen = n;  /* cannot read more than asked */
    nr = fread(p, sizeof(char), rlen, f);
    luaL_addsize(&b, nr);
    n -= nr;  /* still have to read `n' chars */
  } while (n > 0 && nr == rlen);  /* until end of count or eof */
  luaL_pushresult(&b);  /* close buffer */
  return (n == 0 || lua_objlen(L, -1) > 0);
}


static int g_read (lua_State *L, FILE *f, int first) {
  int nargs = lua_gettop(L) - 1;
  int success;
  int n;
  clearerr(f);
  if (nargs == 0) {  /* no arguments? */
    success = read_line(L, f);
    n = first+1;  /* to return 1 result */
  }
  else {  /* ensure stack space for all results and for auxlib's buffer */
    luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
    success = 1;
    for (n = first; nargs-- && success; n++) {
      if (lua_type(L, n) == LUA_TNUMBER) {
        size_t l = (size_t)lua_tointeger(L, n);
        success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
      }
      else {
        const char *p = lua_tostring(L, n);
        luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
        switch (p[1]) {
          case 'n':  /* number */
            success = read_number(L, f);
            break;
          case 'l':  /* line */
            success = read_line(L, f);
            break;
          case 'a':  /* file */
            read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
            success = 1; /* always success */
            break;
          default:
            return luaL_argerror(L, n, "invalid format");
        }
      }
    }
  }
  if (ferror(f))
    return pushresult(L, 0, NULL);
  if (!success) {
    lua_pop(L, 1);  /* remove last result */
    lua_pushnil(L);  /* push nil instead */
  }
  return n - first;
}


static int io_read (lua_State *L) {
  return g_read(L, getiofile(L, IO_INPUT), 1);
}


static int f_read (lua_State *L) {
  return g_read(L, tofile(L), 2);
}


static int io_readline (lua_State *L) {
  FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
  int sucess;
  if (f == NULL)  /* file is already closed? */
    luaL_error(L, "file is already closed");
  sucess = read_line(L, f);
  if (ferror(f))
    return luaL_error(L, "%s", strerror(errno));
  if (sucess) return 1;
  else {  /* EOF */
    if (lua_toboolean(L, lua_upvalueindex(2))) {  /* generator created file? */
      lua_settop(L, 0);
      lua_pushvalue(L, lua_upvalueindex(1));
      aux_close(L);  /* close it */
    }
    return 0;
  }
}

/* }====================================================== */


static int g_write (lua_State *L, FILE *f, int arg) {
  int nargs = lua_gettop(L) - 1;
  int status = 1;
  for (; nargs--; arg++) {
    if (lua_type(L, arg) == LUA_TNUMBER) {
      /* optimization: could be done exactly as for strings */
      status = status &&
          fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
    }
    else {
      size_t l;
      const char *s = luaL_checklstring(L, arg, &l);
      status = status && (fwrite(s, sizeof(char), l, f) == l);
    }
  }
  return pushresult(L, status, NULL);
}


static int io_write (lua_State *L) {
  return g_write(L, getiofile(L, IO_OUTPUT), 1);
}


static int f_write (lua_State *L) {
  return g_write(L, tofile(L), 2);
}


static int f_seek (lua_State *L) {
  static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
  static const char *const modenames[] = {"set", "cur", "end", NULL};
  FILE *f = tofile(L);
  int op = luaL_checkoption(L, 2, "cur", modenames);
  long offset = luaL_optlong(L, 3, 0);
  op = fseek(f, offset, mode[op]);
  if (op)
    return pushresult(L, 0, NULL);  /* error */
  else {
    lua_pushinteger(L, ftell(f));
    return 1;
  }
}


static int f_setvbuf (lua_State *L) {
  static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
  static const char *const modenames[] = {"no", "full", "line", NULL};
  FILE *f = tofile(L);
  int op = luaL_checkoption(L, 2, NULL, modenames);
  lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
  int res = setvbuf(f, NULL, mode[op], sz);
  return pushresult(L, res == 0, NULL);
}


static int io_flush (lua_State *L) {
  return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
}


static int f_flush (lua_State *L) {
  return pushresult(L, fflush(tofile(L)) == 0, NULL);
}


static const luaL_Reg iolib[] = {
  {"close", io_close},
  {"flush", io_flush},
  {"input", io_input},
  {"lines", io_lines},
  {"open", io_open},
  {"output", io_output},
  {"popen", io_popen},
  {"read", io_read},
  {"tmpfile", io_tmpfile},
  {"type", io_type},
  {"write", io_write},
  {NULL, NULL}
};


static const luaL_Reg flib[] = {
  {"close", io_close},
  {"flush", f_flush},
  {"lines", f_lines},
  {"read", f_read},
  {"seek", f_seek},
  {"setvbuf", f_setvbuf},
  {"write", f_write},
  {"__gc", io_gc},
  {"__tostring", io_tostring},
  {NULL, NULL}
};


static void createmeta (lua_State *L) {
  luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
  lua_pushvalue(L, -1);  /* push metatable */
  lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
  luaL_register(L, NULL, flib);  /* file methods */
}


static void createstdfile (lua_State *L, FILE *f, int k, const char *fname) {
  *newfile(L) = f;
  if (k > 0) {
    lua_pushvalue(L, -1);
    lua_rawseti(L, LUA_ENVIRONINDEX, k);
  }
  lua_pushvalue(L, -2);  /* copy environment */
  lua_setfenv(L, -2);  /* set it */
  lua_setfield(L, -3, fname);
}


static void newfenv (lua_State *L, lua_CFunction cls) {
  lua_createtable(L, 0, 1);
  lua_pushcfunction(L, cls);
  lua_setfield(L, -2, "__close");
}


LUALIB_API int luaopen_io (lua_State *L) {
  createmeta(L);
  /* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
  newfenv(L, io_fclose);
  lua_replace(L, LUA_ENVIRONINDEX);
  /* open library */
  luaL_register(L, LUA_IOLIBNAME, iolib);
  /* create (and set) default files */
  newfenv(L, io_noclose);  /* close function for default files */
  createstdfile(L, stdin, IO_INPUT, "stdin");
  createstdfile(L, stdout, IO_OUTPUT, "stdout");
  createstdfile(L, stderr, 0, "stderr");
  lua_pop(L, 1);  /* pop environment for default files */
  lua_getfield(L, -1, "popen");
  newfenv(L, io_pclose);  /* create environment for 'popen' */
  lua_setfenv(L, -2);  /* set fenv for 'popen' */
  lua_pop(L, 1);  /* pop 'popen' */
  return 1;
}
Commit	Line	Data
	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