tac reverses the contents of the file

1. Command function

tac is the reverse spelling function of cat is to display the contents of the file in reverse. cat is to read the file output from the first line of the file, tac is to read the file from the last line and reverse the output.

2. Grammar format

tac  [option]  [file]

Parameter Description

parameter	Parameter Description
-b	Add a split flag at the beginning of the line instead of the end of the line
-r	Parse split flags as regular expressions
-s	Replace line with specified string as split flag

 

3. Example of use

Example 1 

[root@localhost test]# tac test.txt
OK OK OK
WELCOME TO LINUX
HELLO WORLD