Here is another quick example of how to get a count of how many times a string appears. For my example I am going to use this output.
$ cat /etc/passwd | cut -d: -f7 /bin/bash /bin/sh /bin/sh /bin/sh /bin/sync /bin/sh /bin/sh /bin/sh
These are the shells of users on my system, what if I wanted to see what the most common shell was?
$ cat /etc/passwd | cut -d: -f7 | sort | uniq -c | sort -nk1 1 /bin/sync 2 /usr/sbin/nologin 4 /bin/false 5 /bin/bash 20 /bin/sh
In order to get this result I take my output and send it to sort, this command will sort the output alphabetically. From there we pipe it to uniq -c which will find all of the unique occurrences of a string and print the number of times it shows up. We then sort by that number and BAM, we have a list of shells and how many users are using them.
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.
Identify, capture and resolve common issues faced by Red Hat Enterprise Linux administrators using best practices and advanced troubleshooting techniques
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