/*

** $Id: liolib.c,v 2.39a 2003/03/19 21:16:12 roberto Exp $

** Standard I/O (and system) library

** See Copyright Notice in lua.h

*/





#include <errno.h>

#include <locale.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <time.h>



#define liolib_c



#include "lua.h"



#include "lauxlib.h"

#include "lualib.h"







/*

** by default, gcc does not get `tmpname'

*/

#ifndef USE_TMPNAME

#ifdef __GNUC__

#define USE_TMPNAME	0

#else

#define USE_TMPNAME	1

#endif

#endif





/*

** by default, posix systems get `popen'

*/

#ifndef USE_POPEN

#ifdef _POSIX_C_SOURCE

#if _POSIX_C_SOURCE >= 2

#define USE_POPEN	1

#endif

#endif

#endif



#ifndef USE_POPEN

#define USE_POPEN	0

#endif









/*

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

** FILE Operations

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

*/





#if !USE_POPEN

#define pclose(f)    (-1)

#endif





#define FILEHANDLE		"FILE*"



#define IO_INPUT		"_input"

#define IO_OUTPUT		"_output"





static int pushresult (lua_State *L, int i, const char *filename) {

  if (i) {

    lua_pushboolean(L, 1);

    return 1;

  }

  else {

    lua_pushnil(L);

    if (filename)

      lua_pushfstring(L, "%s: %s", filename, strerror(errno));

    else

      lua_pushfstring(L, "%s", strerror(errno));

    lua_pushnumber(L, errno);

    return 3;

  }

}





static FILE **topfile (lua_State *L, int findex) {

  FILE **f = (FILE **)luaL_checkudata(L, findex, FILEHANDLE);

  if (f == NULL) luaL_argerror(L, findex, "bad file");

  return f;

}





static int io_type (lua_State *L) {

  FILE **f = (FILE **)luaL_checkudata(L, 1, FILEHANDLE);

  if (f == NULL) lua_pushnil(L);

  else if (*f == NULL)

    lua_pushliteral(L, "closed file");

  else

    lua_pushliteral(L, "file");

  return 1;

}





static FILE *tofile (lua_State *L, int findex) {

  FILE **f = topfile(L, findex);

  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, FILEHANDLE);

  lua_setmetatable(L, -2);

  return pf;

}





/*

** assumes that top of the stack is the `io' library, and next is

** the `io' metatable

*/

static void registerfile (lua_State *L, FILE *f, const char *name,

                                                 const char *impname) {

  lua_pushstring(L, name);

  *newfile(L) = f;

  if (impname) {

    lua_pushstring(L, impname);

    lua_pushvalue(L, -2);

    lua_settable(L, -6);  /* metatable[impname] = file */

  }

  lua_settable(L, -3);  /* io[name] = file */

}





static int aux_close (lua_State *L) {

  FILE *f = tofile(L, 1);

  if (f == stdin || f == stdout || f == stderr)

    return 0;  /* file cannot be closed */

  else {

    int ok = (pclose(f) != -1) || (fclose(f) == 0);

    if (ok)

      *(FILE **)lua_touserdata(L, 1) = NULL;  /* mark file as closed */

    return ok;

  }

}





static int io_close (lua_State *L) {

  if (lua_isnone(L, 1) && lua_type(L, lua_upvalueindex(1)) == LUA_TTABLE) {

    lua_pushstring(L, IO_OUTPUT);

    lua_rawget(L, lua_upvalueindex(1));

  }

  return pushresult(L, aux_close(L), NULL);

}





static int io_gc (lua_State *L) {

  FILE **f = topfile(L, 1);

  if (*f != NULL)  /* ignore closed files */

    aux_close(L);

  return 0;

}





static int io_tostring (lua_State *L) {

  char buff[128];

  FILE **f = topfile(L, 1);

  if (*f == NULL)

    strcpy(buff, "closed");

  else

    sprintf(buff, "%p", lua_touserdata(L, 1));

  lua_pushfstring(L, "file (%s)", buff);

  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;

}





static int io_popen (lua_State *L) {

#if !USE_POPEN

  luaL_error(L, "`popen' not supported");

  return 0;

#else

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

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

  FILE **pf = newfile(L);

  *pf = popen(filename, mode);

  return (*pf == NULL) ? pushresult(L, 0, filename) : 1;

#endif

}





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, const char *name) {

  lua_pushstring(L, name);

  lua_rawget(L, lua_upvalueindex(1));

  return tofile(L, -1);

}





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

  if (!lua_isnoneornil(L, 1)) {

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

    lua_pushstring(L, name);

    if (filename) {

      FILE **pf = newfile(L);

      *pf = fopen(filename, mode);

      if (*pf == NULL) {

        lua_pushfstring(L, "%s: %s", filename, strerror(errno));

        luaL_argerror(L, 1, lua_tostring(L, -1));

      }

    }

    else {

      tofile(L, 1);  /* check that it's a valid file handle */

      lua_pushvalue(L, 1);

    }

    lua_rawset(L, lua_upvalueindex(1));

  }

  /* return current value */

  lua_pushstring(L, name);

  lua_rawget(L, lua_upvalueindex(1));

  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 close) {

  lua_pushliteral(L, FILEHANDLE);

  lua_rawget(L, LUA_REGISTRYINDEX);

  lua_pushvalue(L, idx);

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

  lua_pushcclosure(L, io_readline, 3);

}





static int f_lines (lua_State *L) {

  tofile(L, 1);  /* 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? */

    lua_pushstring(L, IO_INPUT);

    lua_rawget(L, lua_upvalueindex(1));  /* will iterate over default input */

    return f_lines(L);

  }

  else {

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

    FILE **pf = newfile(L);

    *pf = fopen(filename, "r");

    luaL_argcheck(L, *pf, 1,  strerror(errno));

    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_strlen(L, -1) > 0);  /* check whether read something */

    }

    l = strlen(p);

    if (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_strlen(L, -1) > 0);

}





static int g_read (lua_State *L, FILE *f, int first) {

  int nargs = lua_gettop(L) - 1;

  int success;

  int n;

  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_tonumber(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;

          case 'w':  /* word */

            return luaL_error(L, "obsolete option `*w' to `read'");

          default:

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

        }

      }

    }

  }

  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, 1), 2);

}





static int io_readline (lua_State *L) {

  FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(2));

  if (f == NULL)  /* file is already closed? */

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

  if (read_line(L, f)) return 1;

  else {  /* EOF */

    if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */

      lua_settop(L, 0);

      lua_pushvalue(L, lua_upvalueindex(2));

      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, 1), 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, 1);

  int op = luaL_findstring(luaL_optstring(L, 2, "cur"), modenames);

  long offset = luaL_optlong(L, 3, 0);

  luaL_argcheck(L, op != -1, 2, "invalid mode");

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

  if (op)

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

  else {

    lua_pushnumber(L, ftell(f));

    return 1;

  }

}





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, 1)) == 0, NULL);

}





static const luaL_reg iolib[] = {

  {"input", io_input},

  {"output", io_output},

  {"lines", io_lines},

  {"close", io_close},

  {"flush", io_flush},

  {"open", io_open},

  {"popen", io_popen},

  {"read", io_read},

  {"tmpfile", io_tmpfile},

  {"type", io_type},

  {"write", io_write},

  {NULL, NULL}

};





static const luaL_reg flib[] = {

  {"flush", f_flush},

  {"read", f_read},

  {"lines", f_lines},

  {"seek", f_seek},

  {"write", f_write},

  {"close", io_close},

  {"__gc", io_gc},

  {"__tostring", io_tostring},

  {NULL, NULL}

};





static void createmeta (lua_State *L) {

  luaL_newmetatable(L, FILEHANDLE);  /* create new metatable for file handles */

  /* file methods */

  lua_pushliteral(L, "__index");

  lua_pushvalue(L, -2);  /* push metatable */

  lua_rawset(L, -3);  /* metatable.__index = metatable */

  luaL_openlib(L, NULL, flib, 0);

}



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





/*

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

** Other O.S. Operations

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

*/



static int io_execute (lua_State *L) {

  lua_pushnumber(L, system(luaL_checkstring(L, 1)));

  return 1;

}





static int io_remove (lua_State *L) {

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

  return pushresult(L, remove(filename) == 0, filename);

}





static int io_rename (lua_State *L) {

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

  const char *toname = luaL_checkstring(L, 2);

  return pushresult(L, rename(fromname, toname) == 0, fromname);

}





static int io_tmpname (lua_State *L) {

#if !USE_TMPNAME

  luaL_error(L, "`tmpname' not supported");

  return 0;

#else

  char buff[L_tmpnam];

  if (tmpnam(buff) != buff)

    return luaL_error(L, "unable to generate a unique filename in `tmpname'");

  lua_pushstring(L, buff);

  return 1;

#endif

}





static int io_getenv (lua_State *L) {

  lua_pushstring(L, getenv(luaL_checkstring(L, 1)));  /* if NULL push nil */

  return 1;

}





static int io_clock (lua_State *L) {

  lua_pushnumber(L, ((lua_Number)clock())/(lua_Number)CLOCKS_PER_SEC);

  return 1;

}





/*

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

** Time/Date operations

** { year=%Y, month=%m, day=%d, hour=%H, min=%M, sec=%S,

**   wday=%w+1, yday=%j, isdst=? }

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

*/



static void setfield (lua_State *L, const char *key, int value) {

  lua_pushstring(L, key);

  lua_pushnumber(L, value);

  lua_rawset(L, -3);

}



static void setboolfield (lua_State *L, const char *key, int value) {

  lua_pushstring(L, key);

  lua_pushboolean(L, value);

  lua_rawset(L, -3);

}



static int getboolfield (lua_State *L, const char *key) {

  int res;

  lua_pushstring(L, key);

  lua_gettable(L, -2);

  res = lua_toboolean(L, -1);

  lua_pop(L, 1);

  return res;

}





static int getfield (lua_State *L, const char *key, int d) {

  int res;

  lua_pushstring(L, key);

  lua_gettable(L, -2);

  if (lua_isnumber(L, -1))

    res = (int)(lua_tonumber(L, -1));

  else {

    if (d == -2)

      return luaL_error(L, "field `%s' missing in date table", key);

    res = d;

  }

  lua_pop(L, 1);

  return res;

}





static int io_date (lua_State *L) {

  const char *s = luaL_optstring(L, 1, "%c");

  time_t t = (time_t)(luaL_optnumber(L, 2, -1));

  struct tm *stm;

  if (t == (time_t)(-1))  /* no time given? */

    t = time(NULL);  /* use current time */

  if (*s == '!') {  /* UTC? */

    stm = gmtime(&t);

    s++;  /* skip `!' */

  }

  else

    stm = localtime(&t);

  if (stm == NULL)  /* invalid date? */

    lua_pushnil(L);

  else if (strcmp(s, "*t") == 0) {

    lua_newtable(L);

    setfield(L, "sec", stm->tm_sec);

    setfield(L, "min", stm->tm_min);

    setfield(L, "hour", stm->tm_hour);

    setfield(L, "day", stm->tm_mday);

    setfield(L, "month", stm->tm_mon+1);

    setfield(L, "year", stm->tm_year+1900);

    setfield(L, "wday", stm->tm_wday+1);

    setfield(L, "yday", stm->tm_yday+1);

    setboolfield(L, "isdst", stm->tm_isdst);

  }

  else {

    char b[256];

    if (strftime(b, sizeof(b), s, stm))

      lua_pushstring(L, b);

    else

      return luaL_error(L, "`date' format too long");

  }

  return 1;

}





static int io_time (lua_State *L) {

  if (lua_isnoneornil(L, 1))  /* called without args? */

    lua_pushnumber(L, time(NULL));  /* return current time */

  else {

    time_t t;

    struct tm ts;

    luaL_checktype(L, 1, LUA_TTABLE);

    lua_settop(L, 1);  /* make sure table is at the top */

    ts.tm_sec = getfield(L, "sec", 0);

    ts.tm_min = getfield(L, "min", 0);

    ts.tm_hour = getfield(L, "hour", 12);

    ts.tm_mday = getfield(L, "day", -2);

    ts.tm_mon = getfield(L, "month", -2) - 1;

    ts.tm_year = getfield(L, "year", -2) - 1900;

    ts.tm_isdst = getboolfield(L, "isdst");

    t = mktime(&ts);

    if (t == (time_t)(-1))

      lua_pushnil(L);

    else

      lua_pushnumber(L, t);

  }

  return 1;

}





static int io_difftime (lua_State *L) {

  lua_pushnumber(L, difftime((time_t)(luaL_checknumber(L, 1)),

                             (time_t)(luaL_optnumber(L, 2, 0))));

  return 1;

}



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





static int io_setloc (lua_State *L) {

  static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY,

                      LC_NUMERIC, LC_TIME};

  static const char *const catnames[] = {"all", "collate", "ctype", "monetary",

     "numeric", "time", NULL};

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

  int op = luaL_findstring(luaL_optstring(L, 2, "all"), catnames);

  luaL_argcheck(L, l || lua_isnoneornil(L, 1), 1, "string expected");

  luaL_argcheck(L, op != -1, 2, "invalid option");

  lua_pushstring(L, setlocale(cat[op], l));

  return 1;

}





static int io_exit (lua_State *L) {

  exit(luaL_optint(L, 1, EXIT_SUCCESS));

  return 0;  /* to avoid warnings */

}



static const luaL_reg syslib[] = {

  {"clock",     io_clock},

  {"date",      io_date},

  {"difftime",  io_difftime},

  {"execute",   io_execute},

  {"exit",      io_exit},

  {"getenv",    io_getenv},

  {"remove",    io_remove},

  {"rename",    io_rename},

  {"setlocale", io_setloc},

  {"time",      io_time},

  {"tmpname",   io_tmpname},

  {NULL, NULL}

};



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







LUALIB_API int luaopen_io (lua_State *L) {

  luaL_openlib(L, LUA_OSLIBNAME, syslib, 0);

  createmeta(L);

  lua_pushvalue(L, -1);

  luaL_openlib(L, LUA_IOLIBNAME, iolib, 1);

  /* put predefined file handles into `io' table */

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

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

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

  return 1;

}



