Linux Watch Primer Tutorial

Linux Watch Primer Tutorial

Command line work, when you are wanting to monitor something in real time, can be a tad repetitive, using the keyboard up arrow a lot in our case. But there is the …

• Linux command watch …
  

  watch runs command repeatedly, displaying its output (the first screenfull). This allows you to watch the program output change over time. By default, the program is run every 2 seconds; use -n or –interval to specify a different interval.

  … meaning for “df -h” (disk space) monitoring, for example …
  
watch -d "df -h"

  … not on Mac OS X … but never fear … this useful link helped us to …

• Mac OS X …
  
while clear; date; df -h; do sleep 2; done


… that you can stop with Ctrl-C keyboard press.

Other monitoring ideas (that you could substitute in for “df -h” above) could be …

• show current date and time
  
date

  … up in right hand corner? … try …
  
while sleep 1;do tput sc;tput cup 0 $(($(tput cols)-29));date;tput rc;done &

• top 5 resource hungry processes
  
ps aux | sort -nrk 3,3 | head -n 5

  … or perhaps try something like … top | head -17 | tail -5
• last 5 files in current folder
  
ls -clt | egrep -v '^t' | egrep -v '^d' | head -5

• disk space
  
df -k /

• disk inode count
  
df -i

• history of last logged in users
  
last

• outputs all the service/process using port 80
  
lsof -iTCP:80 -sTCP:LISTEN


… the list can go on and on.

We hope you find this tip helpful …

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