Checking/polling a balance of an address in Electrum via the command line/RPC Suppose, I've dynamically -- via the command line/RPC -- created an address or payment_query in Electrum. And saved its details in a database along with the amount of bitcoins I expect to receive. 

How can then check/poll if that amount of bitcoins has arrived to that address? Also via the command line/RPC. 

I don't want to be notified by Electrum, rather I want to poll Electrum daemon myself. Hence an http request-callback which Electrum can send to a URL isn't an option I'm looking for. Also, at the moment, I don't have a blockchain locally. Maybe later I'll add it, though.
There are several ways depending on what you are using.  If you are wanting to query the daemon - one must assume you are running a Linux box or VPS

You do not want or need an " address balance " - you need YOUR wallet balance

This question has already been partially answered here =>  How would one monitor an address for a transaction and 1 confirmation in PHP?

The best way however is to use what the Electrum docs recommend - a curl call like this =>  curl --data-binary '{"id":"curltext","method":"getbalance","params":{"funded":true}}' http://127.0.0.1:7777

If you are using PHP - it would look something like this:

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, "http://127.0.0.1:7777");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, "{\"id\":\"curltext\",\"method\":\"getbalance\",\"params\":{\"funded\":true}}");
curl_setopt($ch, CURLOPT_POST, 1);

$headers = array();
$headers[] = "Content-Type: application/x-www-form-urlencoded";
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

$result = curl_exec($ch);
if (curl_errno($ch)) {
    echo 'Error:' . curl_error($ch);
}
curl_close ($ch);


You could make this inside a try-catch and trigger it by a cron job running at whatever interval you want to check

What comes back is a JSON-RPC file which you can decode into an array

$result =  json_decode($response, true);


and plug that into another variable for the single thing or things you want to work on from there

$wanted = $result["result"]["xxxxxxxxx"];


any of the parameters can be passed as a variable to the curl call

for instance to add a request it would go like this:

curl_setopt($ch, CURLOPT_POSTFIELDS, "{\"id\":\"curltext\",\"method\":\"addrequest\",\"params\":{\"amount\":\"$how_much\",\"memo\":\"$your_memo-&gt;some_data_field\"}}");


You just need to run a  "getbalance " - or any - command see what it returns and adjust your code to pull the returned value from "result" - you just test for a greater than " 0 " and then empty the wallet by sending it to another wallet and wait for the next payment

You could then use that data to trigger a "do something" like the email example in the above link from the middle example there.