Grep at this point will be too slow, in effect it needs to search whole data for each call. I think I cannot run grep for hundreds of thousands parameters. Am I right?
Why would you need so many parameters? One grep regex can grep Bitcoin addresses. You can Google the regex, or I'll look it up later (I mean next year, cause I'm off for now).Quote
Yes, I am looking for addresses with balances, which I have now, but looking further I need to link addresses with private keys I have. If some of them exist with balances.
I have some of my favourite bash searches collected in this topic. You may also want to look for "bitcoin-tool" to get addresses out of (many) private keys using command line. Good luck 