grep: Counting Results

Written by Benjamin Cane on 2011-09-01

Grep is one of the key Unix/Linux utilities for any user, whether you are a systems administrator, developer or general desktop user using grep can save you a ton of time. Below is an example of counting the number of lines that match the search string. This can be extremely useful if you are looking through large log files or sometimes even the passwd file.

Example:

[[email protected] ~]$ grep -c root /etc/passwd  
2

In the above example you can see there are 2 lines with the word root. The next example will show you the number of lines that do not have the search string of root in them.

[[email protected] ~]$ grep -vc root /etc/passwd  
35

Picture of Benjamin Cane

Benjamin's specialty is keeping the lights on for mission critical systems. He is currently building applications that enable high concurrency financial transactions.

Recently Benjamin published his first book; Red Hat Enterprise Linux Troubleshooting Guide. In addition to writing, he has several Open Source projects focused on making Ops easier. These projects include Automatron, a project enabling auto-healing infrastructure for the masses.


Publications

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

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Excellent, excellent resource for practical guidance on how to troubleshoot a wide variety of problems on Red Hat Linux. I particularly enjoyed how the author made sure to provide solid background and practical examples. I have a lot of experience on Red Hat but still came away with some great practical tools to add to my toolkit. - Amazon Review