Which command outputs kernel event messages as they are generated during system operation?

The command that outputs kernel event messages as they are generated during system operation is the one that effectively provides real-time information about the kernel's operations. This is crucial for system diagnostics and monitoring.

The dmesg command is specifically designed to print kernel-related messages, which helps in understanding what is happening within the kernel after booting or during system activity. This includes information about hardware, drivers, and various events generated by the kernel, allowing system administrators and users to troubleshoot issues effectively.

In contrast, the other commands serve different purposes: lsblk is used to list block devices, lpq checks the status of print jobs in the print queue, and lpr is used to send files to the printer. None of these commands are related to monitoring kernel events or messages, which underscores why dmesg is the correct choice for seeking real-time kernel event messages.