time: Tracking execution time

Written by Benjamin Cane on 2011-08-27 20:33:05

Many times in my life as a sysadmin I've needed to time how long a script or process takes to run. This was usually a manual task until I found the awesomeness of the time command.

Example:

[bca[email protected] ~]$ w  
09:51:24 up 4:41, 2 users, load average: 0.00, 0.01, 0.05  
USER TTY FROM [email protected] IDLE JCPU PCPU WHAT  
bcane tty1 :0 18Aug11 8days 3.40s 0.06s pam: gdm-passwo  
bcane pts/0 :0.0 18Aug11 0.00s 0.03s 0.01s w


[[email protected] ~]$ time w  
09:52:58 up 4:42, 2 users, load average: 0.00, 0.01, 0.05  
USER TTY FROM [email protected] IDLE JCPU PCPU WHAT  
bcane tty1 :0 18Aug11 8days 3.46s 0.06s pam: gdm-passwo  
bcane pts/0 :0.0 18Aug11 0.00s 0.02s 0.00s w  

real 0m0.022s 
user 0m0.002s 
sys 0m0.011s

Or if you want to get fancy you can encapsulate the commands with curly brackets.

[[email protected] ~]$ time { for x in /tmp/v*; do sleep 5; echo $x; done; }  
/tmp/virtual-bcane.Bkon89  
/tmp/virtual-bcane.v9Bm6L  
/tmp/virtual-bcane.WXwFtb  

real 0m15.072s  
user 0m0.001s  
sys 0m0.006s  

Picture of Benjamin Cane

Benjamin is a Systems Architect working in the financial services industry focused on platforms that require Continuous Availability. He has been working with Linux and Unix for over 10 years now and has recently published his first book; Red Hat Enterprise Linux Troubleshooting Guide.

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Identify, capture and resolve common issues faced by Red Hat Enterprise Linux administrators using best practices and advanced troubleshooting techniques

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