lua_pushvalue(L, t);  lua_rawget(L, -2);  if ((n = checkint(L, 2)) >= 0) return n;  return (int)lua_objlen(L, t);}#endif/* }====================================================== */LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,                                                               const char *r) {  const char *wild;  size_t l = strlen(p);  luaL_Buffer b;  luaL_buffinit(L, &b);  while ((wild = strstr(s, p)) != NULL) {    luaL_addlstring(&b, s, wild - s);  /* push prefix */    luaL_addstring(&b, r);  /* push replacement in place of pattern */    s = wild + l;  /* continue after `p' */  }  luaL_addstring(&b, s);  /* push last suffix */  luaL_pushresult(&b);  return lua_tostring(L, -1);}LUALIB_API const char *luaL_findtable (lua_State *L, int idx,                                       const char *fname, int szhint) {  const char *e;  lua_pushvalue(L, idx);  do {    e = strchr(fname, '.');    if (e == NULL) e = fname + strlen(fname);    lua_pushlstring(L, fname, e - fname);    lua_rawget(L, -2);    if (lua_isnil(L, -1)) {  /* no such field? */      lua_pop(L, 1);  /* remove this nil */      lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */      lua_pushlstring(L, fname, e - fname);      lua_pushvalue(L, -2);      lua_settable(L, -4);  /* set new table into field */    }    else if (!lua_istable(L, -1)) {  /* field has a non-table value? */      lua_pop(L, 2);  /* remove table and value */      return fname;  /* return problematic part of the name */    }    lua_remove(L, -2);  /* remove previous table */    fname = e + 1;  } while (*e == '.');  return NULL;}/*** {======================================================** Generic Buffer manipulation** =======================================================*/#define bufflen(B)	((B)->p - (B)->buffer)#define bufffree(B)	((size_t)(LUAL_BUFFERSIZE - bufflen(B)))#define LIMIT	(LUA_MINSTACK/2)static int emptybuffer (luaL_Buffer *B) {  size_t l = bufflen(B);  if (l == 0) return 0;  /* put nothing on stack */  else {    lua_pushlstring(B->L, B->buffer, l);    B->p = B->buffer;    B->lvl++;    return 1;  }}static void adjuststack (luaL_Buffer *B) {  if (B->lvl > 1) {    lua_State *L = B->L;    int toget = 1;  /* number of levels to concat */    size_t toplen = lua_strlen(L, -1);    do {      size_t l = lua_strlen(L, -(toget+1));      if (B->lvl - toget + 1 >= LIMIT || toplen > l) {        toplen += l;        toget++;      }      else break;    } while (toget < B->lvl);    lua_concat(L, toget);    B->lvl = B->lvl - toget + 1;  }}LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {  if (emptybuffer(B))    adjuststack(B);  return B->buffer;}LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {  while (l--)    luaL_addchar(B, *s++);}LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {  luaL_addlstring(B, s, strlen(s));}LUALIB_API void luaL_pushresult (luaL_Buffer *B) {  emptybuffer(B);  lua_concat(B->L, B->lvl);  B->lvl = 1;}LUALIB_API void luaL_addvalue (luaL_Buffer *B) {  lua_State *L = B->L;  size_t vl;  const char *s = lua_tolstring(L, -1, &vl);  if (vl <= bufffree(B)) {  /* fit into buffer? */    memcpy(B->p, s, vl);  /* put it there */    B->p += vl;    lua_pop(L, 1);  /* remove from stack */  }  else {    if (emptybuffer(B))      lua_insert(L, -2);  /* put buffer before new value */    B->lvl++;  /* add new value into B stack */    adjuststack(B);  }}LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {  B->L = L;  B->p = B->buffer;  B->lvl = 0;}/* }====================================================== */LUALIB_API int luaL_ref (lua_State *L, int t) {  int ref;  t = abs_index(L, t);  if (lua_isnil(L, -1)) {    lua_pop(L, 1);  /* remove from stack */    return LUA_REFNIL;  /* `nil' has a unique fixed reference */  }  lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */  ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */  lua_pop(L, 1);  /* remove it from stack */  if (ref != 0) {  /* any free element? */    lua_rawgeti(L, t, ref);  /* remove it from list */    lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */  }  else {  /* no free elements */    ref = (int)lua_objlen(L, t);    ref++;  /* create new reference */  }  lua_rawseti(L, t, ref);  return ref;}LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {  if (ref >= 0) {    t = abs_index(L, t);    lua_rawgeti(L, t, FREELIST_REF);    lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */    lua_pushinteger(L, ref);    lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */  }}/*** {======================================================** Load functions** =======================================================*/typedef struct LoadF {  int extraline;  FILE *f;  char buff[LUAL_BUFFERSIZE];} LoadF;static const char *getF (lua_State *L, void *ud, size_t *size) {  LoadF *lf = (LoadF *)ud;  (void)L;  if (lf->extraline) {    lf->extraline = 0;    *size = 1;    return "\n";  }  if (feof(lf->f)) return NULL;  *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);  return (*size > 0) ? lf->buff : NULL;}static int errfile (lua_State *L, const char *what, int fnameindex) {  const char *serr = strerror(errno);  const char *filename = lua_tostring(L, fnameindex) + 1;  lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);  lua_remove(L, fnameindex);  return LUA_ERRFILE;}LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {  LoadF lf;  int status, readstatus;  int c;  int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */  lf.extraline = 0;  if (filename == NULL) {    lua_pushliteral(L, "=stdin");    lf.f = stdin;  }  else {    lua_pushfstring(L, "@%s", filename);    lf.f = fopen(filename, "r");    if (lf.f == NULL) return errfile(L, "open", fnameindex);  }  c = getc(lf.f);  if (c == '#') {  /* Unix exec. file? */    lf.extraline = 1;    while ((c = getc(lf.f)) != EOF && c != '\n') ;  /* skip first line */    if (c == '\n') c = getc(lf.f);  }  if (c == LUA_SIGNATURE[0] && filename) {  /* binary file? */    lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */    if (lf.f == NULL) return errfile(L, "reopen", fnameindex);    /* skip eventual `#!...' */   while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;    lf.extraline = 0;  }  ungetc(c, lf.f);  status = lua_load(L, getF, &lf, lua_tostring(L, -1));  readstatus = ferror(lf.f);  if (filename) fclose(lf.f);  /* close file (even in case of errors) */  if (readstatus) {    lua_settop(L, fnameindex);  /* ignore results from `lua_load' */    return errfile(L, "read", fnameindex);  }  lua_remove(L, fnameindex);  return status;}typedef struct LoadS {  const char *s;  size_t size;} LoadS;static const char *getS (lua_State *L, void *ud, size_t *size) {  LoadS *ls = (LoadS *)ud;  (void)L;  if (ls->size == 0) return NULL;  *size = ls->size;  ls->size = 0;  return ls->s;}LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,                                const char *name) {  LoadS ls;  ls.s = buff;  ls.size = size;  return lua_load(L, getS, &ls, name);}LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {  return luaL_loadbuffer(L, s, strlen(s), s);}/* }====================================================== */static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {  (void)ud;  (void)osize;  if (nsize == 0) {    free(ptr);    return NULL;  }  else    return realloc(ptr, nsize);}static int panic (lua_State *L) {  (void)L;  /* to avoid warnings */  fprintf(stderr, "PANIC: unprotected error in call to Lua API (%s)\n",                   lua_tostring(L, -1));  return 0;}LUALIB_API lua_State *luaL_newstate (void) {  lua_State *L = lua_newstate(l_alloc, NULL);  if (L) lua_atpanic(L, &panic);  return L;}