/*** $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	2static 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;}