This is the ros2 rosout print utility command which displaies the content of /rosout topic in a nicely formatted and colorized output.
Run ros2 rosout print to get the live stream of the logs.
Run ros2 rosout print -h/--help to print all available command arguments.
The command outputs the log line with the following format:
[ datetime ] [ level ] [ nodename ]: log :[ file : line ( function )]
File, line and function are all optional and are displays when the -f/--function-detail switch is provided.