uniq command takes in a sorted file and reports duplicated lines. With the proper options, it can be used to omit or report unique or repeated lines.
If we use the
uniq command on an unsorted list, it will report unexpected results, so make sure you
$ sort test.txt | uniq
The example file here simply lists the names of a few people. If we
sort then call uniq, it will return all names in the file, just once.
$ cat names.txt Bob Chase Jon Clara Bob Theresa Jon Billy Jonathan Clara Jonathan Bob Jonny $ sort names.txt | uniq Billy Bob Chase Clara Jon Jonathan Jonny Theresa
To output lines that have repeated elements, we pass in the
$ sort names.txt | uniq -d Bob Clara Jon Jonathan
To output lines that occur just once, pass in the
$ sort names.txt | uniq -c Billy Chase Jonny Theresa
-c option, we can find how many times each occurrence occurs.
$ sort names.txt | uniq -c 1 Billy 3 Bob 1 Chase 2 Clara 2 Jon 2 Jonathan 1 Jonny 1 Theresa
Here are a list of the most-used options. Check out the
man page for more.
-d- output only unique lines. This is the default setting.
Stretch out your back and relieve your back muscles with inversion therapy. This device counteracts the forces of gravity on the body by decompressing and elongating the spine. By using this product just ten minutes a day, you can be well on your way to improved circulation and posture while relieving muscle aches, back pain and stress.$$ Check price
This book approaches system administration in a practical way and is an invaluable reference for both new administrators and experienced professionals. It details best practices for every facet of system administration, including storage management, network design and administration, email, web hosting, scripting, and much more.$ Check price