Go Shell script Programming--uniq command

Uniq

Original: http://blog.csdn.net/xifeijian/article/details/9209627

The Uniq command removes duplicate rows from a sorted file, so Uniq is often used in combination with sort. That is, in order for the Uniq to work, all duplicate rows must be contiguous.

Uniq syntax

[[email protected] ~]# uniq [-ICU] options and Parameters:   -I: Ignoring the difference between uppercase and lowercase characters;-C  : Count-u  : Only show unique rows

The contents of Testfile are as follows

Cat Testfilehelloworldfriendhelloworldhello

Deleting an unordered file directly will reveal that no rows have been deleted

#uniq testfile  Helloworldfriendhelloworldhello

Sort files, the default is to go to heavy

#cat Words | Sort |uniqfriendhelloworld

Duplicate rows are deleted after sorting, and the number of occurrences of the row is output at the beginning of the line

#sort Testfile | UNIQ-C1 Friend3 Hello2 World

Displays only duplicate rows, and displays the number of repetitions of the row at the beginning of the line

#sort Testfile | UNIQ-DC3 Hello2 World

Show only rows that are not duplicates

Sort Testfile | Uniq-ufriend  

Go Shell script Programming--uniq command