After fulfilling the steps Pre-requisites, Get the source code, Ensure the security chain and Get external dependencies according to your operating system (Windows, Linux, Mac), you can compile and run an RSK node from command line following these steps.
From the root directory where the code was downloaded, execute:
./gradlew build -x test
After building, run:
java -cp [jar] co.rsk.Start
It’s ready! You are on the Mainnet by default. If you want to switch the networks, read this page.