[SOLVED] JSON-RPC query syntax in curl

I would like to get only some parts of "getpeerinfo" output particularly the "addr", "services", "version" and "subver" of the peers, and put them into a list in text file. So far, I could not figure out the right JSON-RPC syntax to query that using curl.

I can get the entire output of "getpeerinfo" using curl command like below:

Code:

curl --user : --data-binary '{"jsonrpc": "1.0", "id":"getpeerinfo", "method": "getpeerinfo", "params": []}' -H 'content-type: text/plain;' http://127.0.0.1:8332/

I assume that I have to put the right syntax on the "params" part, but I cannot find any information so far. I got errors when I tried for instance the following:

Code:

curl --user : --data-binary '{"jsonrpc": "1.0", "id":"getpeerinfo", "method": "getpeerinfo", "params": [{"addr"}]}' -H 'content-type: text/plain;' http://127.0.0.1:8332/
{"result":null,"error":{"code":-32700,"message":"Parse error"},"id":null}

Could anyone give me hints please?

Thanks a lot in advance for your help.