Standard Output

Part of the Fundamentals section of Coddy's Terminal journey — lesson 37 of 82.

Every command in the terminal has three data streams connected to it. Understanding these streams is the foundation of redirection — one of the most powerful features of the command line.

The first stream is called standard output, often abbreviated as stdout. This is where commands send their normal results. When you run ls or cat, the text you see on screen is coming through standard output.

echo "Hello, World!"

The message Hello, World! is sent to standard output, which by default displays on your terminal screen.

Similarly, when you list files:

ls

The list of filenames flows through standard output to your screen.

By default, standard output is connected to your terminal display. But here is where it gets interesting — you can redirect this output somewhere else, like into a file. Instead of seeing the results on screen, you can capture them for later use.

In the upcoming lessons, you will learn how to redirect standard output to files, and discover the other two streams: standard input and standard error.