Is there any way to get transaction count, slot, Block height or Epoch in program solana

Question

I'm trying to generate random numbers but libs like nanorand, fastrand, oorandom seems doese not work in solana program. So is there any way to get transaction count, slot, Block height or Epoch in program solana?

Answer 1

Yes,

Clock::get().unwrap() contains the slot, epoch, time etc, which are all predictable though, RecentBlockhashes::get().unwrap() is deprecated, but contains the latest blockhashes.

Answer 2

Edit: The answer below is for getting the slot/blockhash off-chain, and the question is for how to get the information on-chain within a program

You can get the slot like this:

const slot = await connection.getSlot()

Or get a recent blockhash like this:

const { blockhash, lastValidBlockHeight } =
    await connection.getLatestBlockhash()