Create and organize files

What you will be able to do

• Create directories and empty files
• Copy, rename, and remove files without using rm -rf
• Recreate the linux-lab layout used in later lessons

Why this matters for DE and AI

Jobs expect a layout: data/ in, logs/ out, scripts/ to run. On a server you often create that layout yourself. Messy directories are how people overwrite yesterday’s extract.

Concepts

Command	What it does
mkdir NAME	Create a directory
mkdir -p a/b/c	Create nested directories, no error if they exist
touch FILE	Create an empty file, or update its timestamp
cp SOURCE DEST	Copy
mv SOURCE DEST	Move or rename
rm FILE	Delete a file
rmdir DIR	Delete an empty directory

There is no Recycle Bin in the terminal. rm is permanent.

We will use this layout for the rest of Linux:

~/dcubes/linux-lab/
  data/
  logs/
  scripts/

Practice on your machine

cd ~/dcubes/linux-lab
mkdir -p data logs scripts
ls

What you should see: data logs scripts (order may differ).

Create a placeholder file and inspect it:

touch data/readme.txt
ls data

Copy it, then rename the copy:

cp data/readme.txt data/readme.copy.txt
mv data/readme.copy.txt data/notes.txt
ls data

What you should see: notes.txt and readme.txt.

Put a line of text into notes.txt using a redirect (full story in lesson 8):

echo "practice files live here" > data/notes.txt

> writes stdout into a file. It overwrites if the file exists.

Read it (full story in the next lesson):

cat data/notes.txt

What you should see: practice files live here

Remove only the extra file:

rm data/readme.txt
ls data

notes.txt should remain. If you removed the wrong file, recreate it with echo as above.

Confirm you did not delete the directories:

ls ~/dcubes/linux-lab

Common mistakes

• rm without checking pwd. Always pwd and ls before deleting.
• mkdir data when data exists. Without -p, mkdir errors. With -p, it is fine.
• Copying a directory with cp without -r. For this lesson we only copy files. Recursive copy is how people duplicate entire datasets by accident — we will wait.

Next

Read files like a data engineer — cat, less, head, tail, and wc -l.