Linux Terminal Command: cat

The cat command is an essential tool in File Manipulation & Viewing. In this tutorial, we will explore what cat does, look at everyday examples, and cover advanced options to supercharge your command-line workflow.

Concept & Explanation

The cat command reads data from files sequentially and prints them to standard output. It is frequently used to inspect small files or merge multiple files.

Common Options & Syntax

cat [options] [arguments]

Here are the most common flags used with cat:

Simple Usage: Basic default commands.
Detailed View: Shows diagnostic information.
Advanced Actions: Can chain parameters for scripting.

1. Interactive Example (Simple)

Here is how most people run the command:

# Example
cat log.txt

What it does: Dumps the contents of ’log.txt’ directly onto the terminal screen.

2. Power-User Example (Advanced)

For scripting and advanced diagnostics, use this configuration:

# Advanced
cat -n file1.txt file2.txt > combined.txt

What it does: Concatenates file1.txt and file2.txt, prepends line numbers to every line (-n), and redirects the output into a new file named ‘combined.txt’.

⚙️ Warning & Common Pitfalls

[!WARNING] Using cat to view large files (e.g. gigabyte log files) will flood the terminal screen and lag the session. Use a pager like less instead.

Here are some related posts on cli_tty1 you might want to check out:

less : File pager for interactive viewing.
screen : Screen multiplexer manager.