Have some ways to match a c struct use rg?

[Lerr1uqs]

like something :

typedef A{
  int bl;
}B;

I tried -U option but still not matched multi-line...

[BurntSushi]

When asking a question and say "I tried ..." but don't actually elaborate on what you tried, it makes answering the question much harder.

In any case, this will match the specific input you gave:

$ cat test.c
typedef A{
  int bl;
}B;
$ rg -U 'typedef A\{(?s:.)*?\}.*;' test.c
1:typedef A{
2:  int bl;
3:}B;

But of course, this is not going to match any typedef. Just the one you gave and ones very similar to it.