uniq命令使用方法

uniq命令的作用：显示唯一的行，对于那些连续重复的行只显示一次！

接下来通过实践实例说明：

[root@stu100 ~]# cat test

boy took bat home

boy took bat home

girl took bat home

dog brought hat home

dog brought hat home

dog brought hat home 

看test文件的内容，可以看到其中的连续重复行

[root@stu100 ~]# uniq test
boy took bat home
girl took bat home
dog brought hat home  

uniq命令不加任何参数，仅显示连续重复的行一次

[root@stu100 ~]# uniq -c test 

 boy took bat home 

 girl took bat home 

 dog brought hat home  

-c 参数显示文件中每行连续出现的次数。

[root@stu100 ~]# uniq -d test  

boy took bat home  

dog brought hat home  

-d选项仅显示文件中连续重复出现的行。

[root@stu100 ~]# uniq -u test  

girl took bat home

-u选项显示文件中没有连续出现的行（去除重复）。

[root@stu100 ~]# uniq -f  -s  test  

boy took bat home

-f（跳过的字段）和-s（跳过的字符数）选项忽略每行的前2个字段，忽略第二个空白字符和第三个字段的首字符（从跳过的字段数开始算起，与-f选项配合使用），结果at home

[root@stu100 ~]# uniq -f  test  

boy took bat home  

dog brought hat home

-f选项忽略每行的第一个字段，这样boy ，girl开头的行看起来是连续重复的行。

lxy@lxy-e440:~$ uniq -w  test.txt 

boy took bat home

girl took bat home

dog brought hat home

lxy@lxy-e440:~$ uniq -w  -u test.txt 

girl took bat home

lxy@lxy-e440:~$ uniq -w  -d test.txt 

boy took bat home

dog brought hat home

-w选项对每行第N 个字符以后的内容不作对照