Watch Command Monitor | Terminal Commands

Basic usage

watch command
watch ls -la

Update interval

# Every 2 seconds (default)
watch -n 2 command

# Every 5 seconds
watch -n 5 df -h

# Every 0.1 seconds
watch -n 0.1 command

Highlight differences

watch -d command
watch --differences command

Cumulative highlights

watch -d=cumulative command

Precise interval

watch -p -n 1 command

No title

watch -t command

Exit on change

watch -g command
# Exits when output changes

Common use cases

Monitor disk space

watch -n 5 df -h

Watch processes

watch -n 1 'ps aux | grep process'
watch -n 1 'ps aux --sort=-%mem | head -20'

Monitor network

watch -n 1 ss -tuln
watch -n 1 'netstat -tuln | grep LISTEN'

System resources

watch -n 1 free -h
watch -n 1 'cat /proc/loadavg'

File changes

watch -n 1 ls -lh file.txt
watch -n 1 'wc -l logfile.log'

Docker containers

watch -n 2 docker ps
watch -n 1 'docker stats --no-stream'

Git status

watch -n 5 git status
watch -n 10 'git log --oneline -5'

Kubernetes

watch -n 2 kubectl get pods
watch -n 1 'kubectl top nodes'

Advanced examples

Multiple commands

watch 'uptime; free -h; df -h /'

With pipes

watch 'ps aux | grep nginx | wc -l'

Colored output

watch --color 'ls --color=always'

Beep on change

watch -b -n 1 command

Monitor log file

watch -n 1 'tail -20 /var/log/app.log'

Comparison with alternatives

# watch (periodic execution)
watch -n 1 command

# while loop (shell script)
while true; do clear; command; sleep 1; done

# tail -f (for log files)
tail -f file.log

Tips

# Use quotes for complex commands
watch 'ps aux | grep nginx'

# Clear screen between runs (alternative)
while sleep 1; do clear; date; ps aux | grep nginx; done

# Save to log
watch -n 60 'date >> /tmp/watch.log; df -h >> /tmp/watch.log'