When running a substrate node, how can I filter log lines according to a word or pattern present in a line of the logs ?
I've tried running:
RUST_LOG=runtime=debug cargo run -- --dev | grep 'INFO'
However that still gives me all the lines of the output, for instance:
2021-03-03 12:01:18.292 DEBUG main runtime: Called should_end_session
2021-03-03 12:01:18.292 DEBUG main runtime: Cannot fetch slot number
2021-03-03 12:01:18.684 INFO main sc_service::builder: 📦 Highest known block at #41
2021-03-03 12:01:18.688 INFO tokio-runtime-worker substrate_prometheus_endpoint::known_os: 〽️ Prometheus server started at 127.0.0.1:9615
2021-03-03 12:01:18.708 INFO main parity_ws: Listening for new connections on 127.0.0.1:9944.
2021-03-03 12:01:18.963 INFO ThreadId(33) parity_ws::io: Accepted a new tcp connection from 127.0.0.1:62079.
2021-03-03 12:01:19.131 WARN event.loop0 sc_rpc_api::errors: Unknown error: Client(UnknownBlock("header not found in db: 0x6eb1…618b"))
2021-03-03 12:01:19.132 WARN event.loop0 sc_rpc_api::errors: Unknown error: Client(UnknownBlock("header not found in db: 0x6eb1…618b"))
2021-03-03 12:01:20.124 INFO ThreadId(33) parity_ws::io: Accepted a new tcp connection from 127.0.0.1:62080.
2021-03-03 12:01:21.433 DEBUG tokio-runtime-worker runtime: Called should_end_session
2021-03-03 12:01:21.433 DEBUG tokio-runtime-worker runtime: Cannot fetch slot number
2021-03-03 12:01:21.536 INFO tokio-runtime-worker sc_basic_authorship::basic_authorship: 🙌 Starting consensus session on top of parent 0xa246d8880f1a820bb2275b78e728471c38c3406271d12b3f852fa717a5338c95
One simple solution: if you redirect stdout and stderr into a file (the &> command) you could filter through this using any method you like.
You may also want to use the tee command to view the output in terminal and to a file