Есть две, возможно, соответствующие команды, подробно изложенные в прекрасном руководстве для less(1)
R Repaint the screen, discarding any buffered input. Useful if the file is changing while it is being viewed. F Scroll forward, and keep trying to read when the end of file is reached. Normally this command would be used when already at the end of the file. It is a way to monitor the tail of a file which is growing while it is being viewed. (The behavior is similar to the "tail -f" command.)