Linux Common Commands--tac

1. Function: Reverse link and reverse print file

2. Usage: tac[option] file,TAC is used in the same way as cat, except that the file content is displayed in the opposite order.

Example:

Example 1: The order in which the content is printed, cat is printed sequentially, and the TAC is printed from the last line to the first row.

[email protected] ~]$ cat >test_cat.txt<<eof

> 5

> 4

> 3

> 2

> 1

> EOF

[email protected] ~]$ cat Test_cat.txt

5

4

3

2

1

[email protected] ~]$ TAC Test_cat.txt

1

2

3

4

5

Example 2:TAC input of keyboard data into a file is also reversed.

[email protected] ~]$ TAC >test_tac.txt<<eof

>5

>4

>3

>2

>1

>eof

[email protected] ~]$ cat Test_tac.txt

1

2

3

4

5

[email protected] ~]$ TAC Test_tac.txt

5

4

3

2

1

Example 3: When a file is stitched, the data will be written in the order of the files, but the contents of the file will be written to the new file in reverse.

[email protected] ~]$ cat >a.txt <<eof

> 1

> 2

> EOF

[email protected] ~]$ cat >b.txt<<eof

> 3

> 4

> EOF

[email protected] ~]$ tac a.txt b.txt >c.txt

[email protected] ~]$ cat C.txt

2

1

4

3

This article is from the "three countries Cold jokes" blog, please be sure to keep this source http://myhwj.blog.51cto.com/9763975/1785265

Linux Common Commands--tac