static void io_read() {
int32 arg = FIRSTARG;
LuaFile *f = (LuaFile *)getfileparam(FINPUT, &arg);
char *buff;
const char *p = luaL_opt_string(arg, "[^\n]*{\n}");
int inskip = 0; // to control {skips}
int c = NEED_OTHER;
luaL_resetbuffer();
while (*p) {
if (*p == '{') {
inskip++;
p++;
} else if (*p == '}') {
if (inskip == 0)
lua_error("unbalanced braces in read pattern");
inskip--;
p++;
} else {
const char *ep; // get what is next
int m; // match result
if (c == NEED_OTHER) {
char z;
if (f->read(&z, 1) != 1)
c = EOF;
else
c = z;
}
m = luaI_singlematch((c == EOF) ? 0 : (char)c, p, &ep);
if (m) {
if (inskip == 0)
luaL_addchar(c);
c = NEED_OTHER;
}
switch (*ep) {
case '*': // repetition
if (!m)
p = ep + 1; // else stay in (repeat) the same item
break;
case '?': // optional
p = ep + 1; // continues reading the pattern
break;
default:
if (m)
p = ep; // continues reading the pattern
else
goto break_while; // pattern fails
}
}
}
break_while:
if (c >= 0) // not EOF nor NEED_OTHER?
f->seek(-1, SEEK_CUR);
luaL_addchar(0);
buff = luaL_buffer();
if (*buff != 0 || *p == 0) // read something or did not fail?
lua_pushstring(buff);
}
