@Option(
      names = "--print-paths-and-exit",
      paramLabel = "<username>",
      description = "Print the configured paths and exit without starting the node.",
      arity = "0..1")
  void setUserName(final String userName) {
    PlatformEnum currentPlatform = SystemInfo.getCurrentPlatform();
    // Only allow on Linux and macOS
    if (currentPlatform == PlatformEnum.LINUX || currentPlatform == PlatformEnum.MACOS) {
      if (userName != null) {
        besuUserName = userName;
      }
      printPathsAndExit = Boolean.TRUE;
    } else {
      throw new UnsupportedOperationException(
          "--print-paths-and-exit is only supported on Linux and macOS.");
    }
  }
Represents the main Besu CLI command that runs the Besu Ethereum client full node.
app/src/main/java/org/hyperledger/besu/cli/BesuCommand.java