watch
watch [-bdehpvtx] [-n seconds] [--beep] [--color] [--differences[=cumulative]] [--errexit] [--exec] [--help] [--interval=seconds] [--no-title] [--precise] [--version] command
watch runs a command repeatedly
A finger-saving utility which repeatedly runs a command so you don't have to.
Examples
Monitor for changes in a file, in this case the stepping of the processor
watch grep MHz /proc/cpuinfo