cat: View File Contents

You can create and move files, but how do you see what is inside one? The simplest tool is cat.

The name is short for concatenate, but its everyday use is plain: print a file's contents to the screen.

cat mission.txt

Mission: explore sector 7.
Status: in progress.

The whole file is dumped into the terminal at once.

When to use cat

cat is perfect for short files: a few lines you want to read in one glance. For very long files it floods the screen; you will meet better tools (head, tail, less) for those soon.

Printing several files

Give cat more than one file and it prints them one after another, joined together:

cat part1.txt part2.txt

That "joining" is where the name concatenate comes from.

Like ls and pwd, cat only reads. It never changes the file.

Mission: Read and Archive the Briefing

A new briefing has arrived split across two files in your home directory: the main order in briefing.txt and an addendum.txt with last-minute details. Read them, then set aside a copy of the main briefing for the archive.

1. Display briefing.txt to see the main order.
2. Display both files joined together in a single command, so you have the full briefing at a glance.
3. Create a folder called archive and copy briefing.txt into it under the name briefing-old.txt.
4. Confirm the archive by displaying the contents of archive/briefing-old.txt.

Expected result

Both briefings appear in the terminal. The archive folder holds a faithful copy of the briefing, and displaying it shows exactly the same text as the original.