watch -n 1 'ls -l'
'-n 1' - time (in seconds) to refresh command output
'ls -l' - command to execute in interval above
When we add '-d' option (help: highlight changes between updates), watch inform Us what was changed between command executions.
Example for 'ls' command below:
watch --color -n 10 -d 'ls -la'
After change in directory structure watch informs us about changes: