static void read_all (lua_State *L, FILE *f) {
size_t rlen = LUAL_BUFFERSIZE; /* how much to read in each cycle */
l_seeknum old, nrlen = 0; /* for testing file size */
luaL_Buffer b;
luaL_buffinit(L, &b);
/* speed up loading of not too large files: */
old = l_ftell(f);
if ((l_fseek(f, 0, SEEK_END) >= 0) &&
((nrlen = l_ftell(f)) > 0) && nrlen < 1000 * 1000 * 100) {
rlen = nrlen;
}
l_fseek(f, old, SEEK_SET);
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 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;
}
}