user57405: Is there a way to extract old OP_RETURN transactions from the commandline with bitcoin-cli or something? 
Something in the way of getAllOpRetFromBlock(345345) ...

user51948: There is not quite the method you are looking for, but you can use the getblock call which takes the block hash (not height, you can get the hash of a specific height using getblockhash method). That will give you the block, and you would then need to write a script to iterate through the transactions in the block and find ones which have an OP_RETURN output.

57405: <p>Is there a way to extract old OP_RETURN transactions from the commandline with bitcoin-cli or something? 
Something in the way of getAllOpRetFromBlock(345345) ...</p>
 51948: <p>There is not quite the method you are looking for, but you can use the <code>getblock</code> call which takes the block hash (not height, you can get the hash of a specific height using <code>getblockhash</code> method). That will give you the block, and you would then need to write a script to iterate through the transactions in the block and find ones which have an OP_RETURN output.</p>
