Basic Linux Terminal Commands Everyone Should Know

Coming from Windows? The terminal is Linux's equivalent of Command Prompt or PowerShell, but it is far more central to how the system is used and maintained. The good news is that the commands below are remarkably consistent: they come from the GNU coreutils and the Bash shell, so they work the same on Ubuntu, Debian, Fedora, Arch and nearly every other distribution. The main thing that changes between distros is the package manager, which we cover near the end.

1. Getting around: pwd, ls, cd

Everything in Linux lives in a single tree that starts at / (the "root"). Your personal files live under your home directory, written as ~ (for example /home/alex). These three commands tell you where you are and let you move:

A few moves worth memorising:

cd ~        # go to your home directory
cd ..       # move up one level
cd -        # jump back to the previous directory
ls -lah     # long listing, all files (incl. hidden), human-readable sizes

The -a flag reveals hidden files — the GNU coreutils manual defines it as not ignoring file names that start with a dot. -l gives the detailed "long" view with permissions and sizes, and -h prints sizes as KB/MB/GB instead of raw bytes. Flags can be combined, so ls -lah does all three at once.

2. Working with files: cp, mv, rm, mkdir, touch, cat, less

This group creates, copies, moves, reads and deletes files and folders.

To copy or delete a whole folder, add the recursive flag -r:

mkdir -p projects/website/css   # -p creates the whole path at once
cp -r projects backup-projects  # copy a directory and everything in it
mv report.pdf ~/Documents/      # move a file into another folder
rm -r old-project               # delete a directory and its contents

Inside less, use the arrow keys or Space to scroll, /word to search, and q to quit. Unlike cat, it does not flood your screen with a huge file all at once.

3. Finding things: find and grep

Two different search tools that people often confuse. find searches for files by name, type, size or age. grep searches inside files for text.

# find: locate files by name under the current folder
find . -name "*.log"

# find: files larger than 100 MB anywhere under /var
find /var -type f -size +100M

# grep: show every line in a file that contains "error"
grep "error" /var/log/syslog

# grep: search recursively through a whole project, case-insensitive
grep -ri "api_key" ./src

You will also see the two combined with a "pipe" (|), which sends the output of one command into another — for example ls -la | grep ".txt" lists only the text files. Pipes are one of the most powerful ideas in the Linux shell.

4. Permissions: chmod and chown

Every file has an owner, a group, and a set of read (r), write (w) and execute (x) permissions for the owner, the group and everyone else. Run ls -l and the first column (like -rwxr-xr--) shows exactly that.

chmod +x deploy.sh          # make a script executable
chmod 644 index.html        # owner read/write, everyone else read-only
chmod -R 755 public/        # apply recursively to a folder
sudo chown -R alex:alex /var/www/site   # give a user ownership of a tree

The three-digit numbers are a shorthand: 4 = read, 2 = write, 1 = execute, added together per group. So 755 means the owner has 7 (read+write+execute) and the group and others have 5 (read+execute). Changing ownership almost always needs sudo, which we cover below.

5. Processes: ps, top/htop, kill

A "process" is any running program. These commands let you see what is running and stop something that has frozen or is hogging resources.

ps aux | grep firefox   # find a program's process ID (PID)
kill 4123               # ask process 4123 to close gracefully
kill -9 4123            # force it to stop if it will not respond

Inside top, press q to quit. htop is often nicer to use but is not always installed by default — you can add it with your package manager (see the next section). Use kill -9 only as a last resort, because it stops a program instantly without letting it save.

6. Installing software: apt and dnf

This is the one area that genuinely differs between distributions. Instead of downloading installers from websites, Linux installs software from curated repositories using a package manager. Which one you use depends on your distro family:

On Debian and Ubuntu it is standard to run sudo apt update before installing, so the system knows about the latest available versions — Ubuntu's official package management documentation describes it as updating the local package index with the latest changes in the repositories:

sudo apt update && sudo apt install htop

On current Fedora releases, dnf is the modern DNF5 tool — the accepted Fedora change proposal switched the /usr/bin/dnf symlink to dnf5 for Fedora Linux 41 — and the everyday commands shown above are unchanged.

7. Running as administrator: sudo

Many commands that change the system — installing packages, editing files outside your home folder, changing ownership — require administrator (root) privileges. You get them by prefixing a command with sudo ("superuser do") and entering your password:

sudo apt install htop            # install system-wide software
sudo nano /etc/hosts             # edit a protected system file

8. Getting help: man and --help

You never need to memorise every option. Two built-in references cover almost everything, work offline, and describe the exact version installed on your machine:

man ls        # open the full manual for ls  (press q to quit)
ls --help     # quick summary of ls's options
man man       # yes, even man has a manual

Use --help for a fast reminder of the available flags, and man when you want the full explanation with examples. Between them, they are the most reliable Linux reference there is.

Quick reference cheat sheet