Essential Linux commands for a solid start.

The terminal is a way to talk to your system through text. Each command does a small task. You do not need to memorize everything: start with a few commands, read their output, and use help when needed.

Know where you are

Create and organize files

mkdir materials             # creates a folder
mkdir -p notes/2026/october # creates a series of folders
touch reminder.txt          # creates an empty file
cp source.txt copy.txt      # copies a file
mv old.txt new.txt          # moves or renames a file

Use cp -r source-folder copied-folder to copy an entire folder. Before moving or replacing files, run ls to check names and destination.

Read without editing

cat reminder.txt       # shows a short file
less large-file.log    # paged reading; press q to exit
head -n 20 file.txt    # shows the first 20 lines
tail -n 20 file.log    # shows the last 20 lines
tail -f app.log        # follows new lines in real time

Find files and text

find . -name "*.html"    # finds HTML files below the current folder
rg "search phrase"       # searches for text in project files
rg --files | rg "config" # lists files with config in their name

rg, also called ripgrep, is fast for searching projects. If it is not installed, grep is a common alternative: grep -R "phrase" ..

Permissions and processes

chmod +x script.sh  # lets a script run
ps aux             # lists running processes
man ls             # opens the ls manual

Avoid using sudo by habit. It runs a command with administrative powers and can modify important parts of the system. Read the command and understand why it is needed before confirming it.

The command that deserves extra care

A routine for building confidence

1. Use pwd and ls before creating, moving, or deleting.
2. Prefer testing in an example folder first.
3. Use Tab to complete paths and reduce typing errors.
4. Read man command-name whenever an option is unclear.