13 Basic Cat Command Examples in Linux

The cat (short for “concatenate“) command is one of the most frequently used command in Linux/Unix like operating systems. cat command allows us to create single or multiple files, view contain of file, concatenate files and redirect output in terminal or files. In this article, we are going to find out handy use of cat commands with their examples in Linux.

13 Basic Cat Command Examples in Linux

13 Basic Cat Command

General Syntax

1. Display Contents of File

In the below example, it will show contents of /etc/passwd file.

2. View Contents of Multiple Files in terminal

In below example, it will display contents of test and test1 file in terminal.

3. Create a File with Cat Command

We will create a file called test2 file with below command.

Awaits input from user, type desired text and press CTRL+D (hold down Ctrl Key and type ‘d‘) to exit. The text will be written in test2 file. You can see content of file with following cat command.

4. Use Cat Command with More & Less Options

If file having large number of content that won’t fit in output terminal and screen scrolls up very fast, we can use parameters more and less with cat command as show above.

5. Display Line Numbers in File

With -n option you could see the line numbers of a file song.txt in the output terminal.

6. Display $ at the End of File

In the below, you can see with -e option that ‘$‘ is shows at the end of line and also in space showing ‘$‘ if there is any gap between paragraphs. This options is useful to squeeze multiple lines in a single line.

7. Display Tab separated Lines in File

In the below output, we could see TAB space is filled up with ‘^I‘ character.

8. Display Multiple Files at Once

In the below example we have three files testtest1 and test2 and able to view the contents of those file as shown above. We need to separate each file with ; (semi colon).

9. Use Standard Output with Redirection Operator

We can redirect standard output of a file into a new file else existing file with ‘>‘ (greater than) symbol. Careful, existing contents of test1 will be overwritten by contents of test file.

10. Appending Standard Output with Redirection Operator

Appends in existing file with ‘>>‘ (double greater than) symbol. Here, contents of test file will be appended at the end of test1 file.

11. Redirecting Standard Input with Redirection Operator

When you use the redirect with standard input ‘<‘ (less than symbol), it use file name test2 as a input for a command and output will be shown in a terminal.

12. Redirecting Multiple Files Contain in a Single File

This will create a file called test3 and all output will be redirected in a newly created file.

13. Sorting Contents of Multiple Files in a Single File

This will create a file test4 and output of cat command is piped to sort and result will be redirected in a newly created file.

This article shows the basic commands that may help you to explore cat command. You may refer man page of cat command if you want to know more options. In out next article we will cover more advanced cat commands.

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