What is the purpose of cat command?

The Purpose of the cat Command in Linux

The cat command, short for "concatenate", is a fundamental command in the Linux operating system that is used for a variety of purposes. Its primary function is to display the contents of a file or multiple files on the terminal, but it can also be used for other tasks such as creating, combining, and manipulating text files.

Displaying File Contents

The most common use of the cat command is to display the contents of a file on the terminal. This can be done by simply typing cat followed by the name of the file:

cat file.txt

This will output the entire contents of the file.txt file to the terminal. If you have multiple files, you can list them all after the cat command, and it will display the contents of each file in the order they are listed:

cat file1.txt file2.txt file3.txt

Creating New Files

The cat command can also be used to create new files. This is done by redirecting the input from the terminal to a new file using the > operator:

cat > new_file.txt
This is the content of the new file.

After typing the command, you can start typing the content of the new file. When you're done, press Ctrl+D to save the file and exit.

Appending to Existing Files

Similarly, you can use the cat command to append content to an existing file. This is done by using the >> operator instead of the > operator:

cat >> existing_file.txt
This text will be added to the end of the file.

Again, press Ctrl+D to save the file and exit.

Combining Files

The cat command can also be used to combine the contents of multiple files into a single file. This is done by redirecting the output of the cat command to a new file:

cat file1.txt file2.txt file3.txt > combined_file.txt

This will create a new file called combined_file.txt that contains the contents of file1.txt, file2.txt, and file3.txt concatenated together.

Mermaid Diagram

Here's a Mermaid diagram that summarizes the key uses of the cat command:

In conclusion, the cat command is a versatile and powerful tool in the Linux command-line interface. It allows you to quickly view, create, and manipulate text files, making it an essential part of any Linux user's toolkit.