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/*

** $Id: liolib.c,v 2.108 2011/11/25 12:50:03 roberto Exp $

** Standard I/O (and system) library

** See Copyright Notice in lua.h

*/

/*

** POSIX idiosyncrasy!

** This definition must come before the inclusion of 'stdio.h'; it

** should not affect non-POSIX systems

*/

#if !defined(_FILE_OFFSET_BITS)

#define _FILE_OFFSET_BITS 64

#endif

#include 

#include 

#include 

#include 

#define liolib_c

#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"

#include "lualib.h"

/*

** {======================================================

** lua_popen spawns a new process connected to the current

** one through the file streams.

** =======================================================

*/

#if !defined(lua_popen)	/* { */

#if defined(LUA_USE_POPEN)	/* { */

#define lua_popen(L,c,m)	((void)L, fflush(NULL), popen(c,m))

#define lua_pclose(L,file)	((void)L, pclose(file))

#elif defined(LUA_WIN)		/* }{ */

#define lua_popen(L,c,m)		((void)L, _popen(c,m))

#define lua_pclose(L,file)		((void)L, _pclose(file))

#else				/* }{ */

#define lua_popen(L,c,m)		((void)((void)c, m),  \

		luaL_error(L, LUA_QL("popen") " not supported"), (FILE*)0)

#define lua_pclose(L,file)		((void)((void)L, file), -1)

#endif				/* } */

#endif			/* } */

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

/*

** {======================================================

** lua_fseek/lua_ftell: configuration for longer offsets

** =======================================================

*/

#if !defined(lua_fseek)	/* { */

#if defined(LUA_USE_POSIX)

#define l_fseek(f,o,w)		fseeko(f,o,w)

#define l_ftell(f)		ftello(f)

#define l_seeknum		off_t

#elif defined(LUA_WIN) && !defined(_CRTIMP_TYPEINFO) \

   && defined(_MSC_VER) && (_MSC_VER >= 1400)

/* Windows (but not DDK) and Visual C++ 2005 or higher */

#define l_fseek(f,o,w)		_fseeki64(f,o,w)

#define l_ftell(f)		_ftelli64(f)

#define l_seeknum		__int64

#else

#define l_fseek(f,o,w)		fseek(f,o,w)

#define l_ftell(f)		ftell(f)

#define l_seeknum		long

#endif

#endif			/* } */

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

#define IO_PREFIX	"_IO_"

#define IO_INPUT	(IO_PREFIX "input")

#define IO_OUTPUT	(IO_PREFIX "output")

typedef luaL_Stream LStream;

#define tolstream(L)	((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE))

#define isclosed(p)	((p)->closef == NULL)

static int io_type (lua_State *L) {

  LStream *p;

  luaL_checkany(L, 1);

  p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);

  if (p == NULL)

    lua_pushnil(L);  /* not a file */

  else if (isclosed(p))

    lua_pushliteral(L, "closed file");

  else

    lua_pushliteral(L, "file");

  return 1;

}

static int f_tostring (lua_State *L) {

  LStream *p = tolstream(L);

  if (isclosed(p))

    lua_pushliteral(L, "file (closed)");

  else

    lua_pushfstring(L, "file (%p)", p->f);

  return 1;

}

static FILE *tofile (lua_State *L) {

  LStream *p = tolstream(L);

  if (isclosed(p))

    luaL_error(L, "attempt to use a closed file");

  lua_assert(p->f);

  return p->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 LStream *newprefile (lua_State *L) {

  LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));

  p->closef = NULL;  /* mark file handle as 'closed' */

  luaL_setmetatable(L, LUA_FILEHANDLE);

  return p;

}

static int aux_close (lua_State *L) {

  LStream *p = tolstream(L);

  lua_CFunction cf = p->closef;

  p->closef = NULL;  /* mark stream as closed */

  return (*cf)(L);  /* close it */

}

static int io_close (lua_State *L) {

  if (lua_isnone(L, 1))  /* no argument? */

    lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT);  /* use standard output */

  tofile(L);  /* make sure argument is an open stream */

  return aux_close(L);

}

static int f_gc (lua_State *L) {

  LStream *p = tolstream(L);

  if (!isclosed(p) && p->f != NULL)

    aux_close(L);  /* ignore closed and incompletely open files */

  return 0;

}

/*

** function to close regular files

*/

static int io_fclose (lua_State *L) {

  LStream *p = tolstream(L);

  int res = fclose(p->f);

  return luaL_fileresult(L, (res == 0), NULL);

}

static LStream *newfile (lua_State *L) {

  LStream *p = newprefile(L);

  p->f = NULL;

  p->closef = &io_fclose;

  return p;

}

static void opencheck (lua_State *L, const char *fname, const char *mode) {

  LStream *p = newfile(L);

  p->f = fopen(fname, mode);

  if (p->f == NULL)

    luaL_error(L, "cannot open file " LUA_QS " (%s)", fname, strerror(errno));

}

static int io_open (lua_State *L) {

  const char *filename = luaL_checkstring(L, 1);

  const char *mode = luaL_optstring(L, 2, "r");

  LStream *p = newfile(L);

  int i = 0;

  /* check whether 'mode' matches '[rwa]%+?b?' */

  if (!(mode[i] != '\0' && strchr("rwa", mode[i++]) != NULL &&

       (mode[i] != '+' || ++i) &&  /* skip if char is '+' */

       (mode[i] != 'b' || ++i) &&  /* skip if char is 'b' */

       (mode[i] == '\0')))

    return luaL_error(L, "invalid mode " LUA_QS

                         " (should match " LUA_QL("[rwa]%%+?b?") ")", mode);

  p->f = fopen(filename, mode);

  return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;

}

/*

** function to close 'popen' files

*/

static int io_pclose (lua_State *L) {

  LStream *p = tolstream(L);

  return luaL_execresult(L, lua_pclose(L, p->f));

}

static int io_popen (lua_State *L) {

  const char *filename = luaL_checkstring(L, 1);

  const char *mode = luaL_optstring(L, 2, "r");

  LStream *p = newprefile(L);

  p->f = lua_popen(L, filename, mode);

  p->closef = &io_pclose;

  return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;

}

static int io_tmpfile (lua_State *L) {

  LStream *p = newfile(L);

  p->f = tmpfile();

  return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;

}

static FILE *getiofile (lua_State *L, const char *findex) {

  LStream *p;

  lua_getfield(L, LUA_REGISTRYINDEX, findex);

  p = (LStream *)lua_touserdata(L, -1);

  if (isclosed(p))

    luaL_error(L, "standard %s file is closed", findex + strlen(IO_PREFIX));

  return p->f;

}

static int g_iofile (lua_State *L, const char *f, const char *mode) {

  if (!lua_isnoneornil(L, 1)) {

    const char *filename = lua_tostring(L, 1);

    if (filename)

      opencheck(L, filename, mode);

    else {

      tofile(L);  /* check that it's a valid file handle */

      lua_pushvalue(L, 1);

    }

    lua_setfield(L, LUA_REGISTRYINDEX, f);

  }

  /* return current value */

  lua_getfield(L, LUA_REGISTRYINDEX, 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 toclose) {

  int i;

  int n = lua_gettop(L) - 1;  /* number of arguments to read */

  /* ensure that arguments will fit here and into 'io_readline' stack */

  luaL_argcheck(L, n <= LUA_MINSTACK - 3, LUA_MINSTACK - 3, "too many options");

  lua_pushvalue(L, 1);  /* file handle */

  lua_pushinteger(L, n);  /* number of arguments to read */

  lua_pushboolean(L, toclose);  /* close/not close file when finished */

  for (i = 1; i <= n; i++) lua_pushvalue(L, i + 1);  /* copy arguments */

  lua_pushcclosure(L, io_readline, 3 + n);

}

static int f_lines (lua_State *L) {

  tofile(L);  /* check that it's a valid file handle */

  aux_lines(L, 0);

  return 1;

}

static int io_lines (lua_State *L) {

  int toclose;

  if (lua_isnone(L, 1)) lua_pushnil(L);  /* at least one argument */

  if (lua_isnil(L, 1)) {  /* no file name? */

    lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT);  /* get default input */

    lua_replace(L, 1);  /* put it at index 1 */

    tofile(L);  /* check that it's a valid file handle */

    toclose = 0;  /* do not close it after iteration */

  }

  else {  /* open a new file */

    const char *filename = luaL_checkstring(L, 1);

    opencheck(L, filename, "r");

    lua_replace(L, 1);  /* put file at index 1 */

    toclose = 1;  /* close it after iteration */

  }

  aux_lines(L, toclose);

  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 {

   lua_pushnil(L);  /* "result" to be removed */

   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, int chop) {

  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_rawlen(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 - chop);  /* chop 'eol' if needed */

      luaL_pushresult(&b);  /* close buffer */

      return 1;  /* read at least an `eol' */

    }

  }

}

#define MAX_SIZE_T	(~(size_t)0)

static void read_all (lua_State *L, FILE *f) {

  size_t rlen = LUAL_BUFFERSIZE;  /* how much to read in each cycle */

  luaL_Buffer b;

  luaL_buffinit(L, &b);

  for (;;) {

    char *p = luaL_prepbuffsize(&b, rlen);

    size_t nr = fread(p, sizeof(char), rlen, f);

    luaL_addsize(&b, nr);

    if (nr < rlen) break;  /* eof? */

    else if (rlen <= (MAX_SIZE_T / 4))  /* avoid buffers too large */

      rlen *= 2;  /* double buffer size at each iteration */

  }

  luaL_pushresult(&b);  /* close buffer */

}

static int read_chars (lua_State *L, FILE *f, size_t n) {

  size_t nr;  /* number of chars actually read */

  char *p;

  luaL_Buffer b;

  luaL_buffinit(L, &b);

  p = luaL_prepbuffsize(&b, n);  /* prepare buffer to read whole block */

  nr = fread(p, sizeof(char), n, f);  /* try to read 'n' chars */

  luaL_addsize(&b, nr);

  luaL_pushresult(&b);  /* close buffer */

  return (nr > 0);  /* true iff read something */

}

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, 1);

    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, 1);

            break;

          case 'L':  /* line with end-of-line */

            success = read_line(L, f, 0);

            break;

          case 'a':  /* file */

            read_all(L, f);  /* read entire file */

            success = 1; /* always success */

            break;

          default:

            return luaL_argerror(L, n, "invalid format");

        }

      }

    }

  }

  if (ferror(f))

    return luaL_fileresult(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) {

  LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));

  int i;

  int n = (int)lua_tointeger(L, lua_upvalueindex(2));

  if (isclosed(p))  /* file is already closed? */

    return luaL_error(L, "file is already closed");

  lua_settop(L , 1);

  for (i = 1; i <= n; i++)  /* push arguments to 'g_read' */

    lua_pushvalue(L, lua_upvalueindex(3 + i));

  n = g_read(L, p->f, 2);  /* 'n' is number of results */

  lua_assert(n > 0);  /* should return at least a nil */

  if (!lua_isnil(L, -n))  /* read at least one value? */

    return n;  /* return them */

  else {  /* first result is nil: EOF or error */

    if (n > 1) {  /* is there error information? */

      /* 2nd result is error message */

      return luaL_error(L, "%s", lua_tostring(L, -n + 1));

    }

    if (lua_toboolean(L, lua_upvalueindex(3))) {  /* 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) - arg;

  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);

    }

  }

  if (status) return 1;  /* file handle already on stack top */

  else return luaL_fileresult(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) {

  FILE *f = tofile(L);

  lua_pushvalue(L, 1);  /* push file at the stack top (to be returned) */

  return g_write(L, f, 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);

  lua_Number p3 = luaL_optnumber(L, 3, 0);

  l_seeknum offset = (l_seeknum)p3;

  luaL_argcheck(L, (lua_Number)offset == p3, 3,

                  "not an integer in proper range");

  op = l_fseek(f, offset, mode[op]);

  if (op)

    return luaL_fileresult(L, 0, NULL);  /* error */

  else {

    lua_pushnumber(L, (lua_Number)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 luaL_fileresult(L, res == 0, NULL);

}

static int io_flush (lua_State *L) {

  return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);

}

static int f_flush (lua_State *L) {

  return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);

}

/*

** functions for 'io' library

*/

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}

};

/*

** methods for file handles

*/

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", f_gc},

  {"__tostring", f_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_setfuncs(L, flib, 0);  /* add file methods to new metatable */

  lua_pop(L, 1);  /* pop new metatable */

}

/*

** function to (not) close the standard files stdin, stdout, and stderr

*/

static int io_noclose (lua_State *L) {

  LStream *p = tolstream(L);

  p->closef = &io_noclose;  /* keep file opened */

  lua_pushnil(L);

  lua_pushliteral(L, "cannot close standard file");

  return 2;

}

static void createstdfile (lua_State *L, FILE *f, const char *k,

                           const char *fname) {

  LStream *p = newprefile(L);

  p->f = f;

  p->closef = &io_noclose;

  if (k != NULL) {

    lua_pushvalue(L, -1);

    lua_setfield(L, LUA_REGISTRYINDEX, k);  /* add file to registry */

  }

  lua_setfield(L, -2, fname);  /* add file to module */

}

LUAMOD_API int luaopen_io (lua_State *L) {

  luaL_newlib(L, iolib);  /* new module */

  createmeta(L);

  /* create (and set) default files */

  createstdfile(L, stdin, IO_INPUT, "stdin");

  createstdfile(L, stdout, IO_OUTPUT, "stdout");

  createstdfile(L, stderr, NULL, "stderr");

  return 1;

}