A somewhat lesser known linux command is
watch. It will display the output of a regular command and update the screen if that output changes. Here are some helpful use cases.
Watch for directory contents changing
Try the command:
watch -d ls -la
You’ll see the output of
ls -la and every 2 seconds the screen will refresh if there are any changes. If files grow in size, get removed, or added, you’ll see it highlighted on the screen when it happens.
-d switch will highlight changes for you to make it easier to spot.
Watch disk space grow or shrink
Try this command:
watch -d df -h
You’ll see an output of the free disk space in human readable format and if it changes it will update live every 2 seconds.