How to use the Cat Command in Linux/Unix

Syntax and exemples for Cat (Unix command)


The Linux & Unix cat command is a useful utility for displaying the contents of a file, but it can do much more. It is one of the most commonly used commands in Linux, and it is often used in combination with other commands to perform powerful operations. In this guide, we will look at the basics of the cat command and its various uses.


The cat command has the following syntax:

cat [options] [file_name]


The cat command has several options available to use, including:

  • -A: Prints out all characters, including non-printing characters
  • -b: Number non-blank output lines
  • -E: Display a $ at the end of each line
  • -n: Number all output lines
  • -s: Squeeze multiple blank lines into one


Here are some examples of how to use the cat command:

  • To view the contents of a file:
$ cat file.txt
  • To view the contents of multiple files:
$ cat file1 file2 file3
  • To print out all characters, including non-printing characters:
$ cat -A filename
  • To number all lines of output:
$ cat -n filename
  • To squeeze multiple blank lines into one:
$ cat -s filename


The cat command is a powerful tool for viewing and manipulating files in the Linux command line. With the usage, options, and examples outlined in this guide, you should be able to get up and running quickly with the cat command.