Basic Linux Commands: Complete List for Beginners

Introduction

Working in Linux without knowing basic commands is like reading a book without knowing the alphabet. The terminal (command line) is the primary tool for administration, configuration, and everyday tasks in Linux. By mastering a few dozen key commands, you'll be able to navigate the file system quickly, manage files and processes, and get system information. This guide is your starting point: we've collected the most important commands with explanations and examples that will be useful for anyone starting with Linux.

Requirements

Before you begin, make sure you have:

• Access to a Linux terminal (locally, via a virtual machine, or remotely through SSH).
• Basic understanding of the file system structure (what directories and files are).
• Permissions to perform operations (for some commands, like rm or sudo, administrator rights may be required).

Step 1: Navigating the File System

The first thing to learn is understanding where you are and moving between directories.

pwd — Where am I?

The pwd (print working directory) command shows the current full path to the directory.

pwd
# Example output: /home/username

cd — Change Directory

cd (change directory) switches you to the specified directory.

cd /var/log   # navigate to /var/log
cd ~          # go to the home directory
cd ..         # move up one level
cd -          # return to the previous directory

ls — List Contents

ls (list) outputs a list of files and subdirectories in the current directory.

ls                # simple list
ls -l             # detailed list (permissions, size, date)
ls -a             # show hidden files (starting with .)
ls -lh            # sizes in a readable format (KB, MB)

Step 2: Managing Files and Directories

Now let's learn how to create, copy, move, and delete file system objects.

Creation

• touch filename — create an empty file.
• mkdir dirname — create a new directory.
• mkdir -p path/to/dir — create nested directories (if intermediates don't exist).

touch newfile.txt
mkdir documents
mkdir -p projects/2024/plan

Copying and Moving

• cp source destination — copy a file or directory.
• mv source destination — move or rename a file/directory.

cp file.txt backup/
cp -r dir1 dir2   # recursive directory copy
mv old.txt new.txt
mv file.txt /home/user/Documents/

Deletion

• rm file — delete a file.
• rm -r dir — delete a directory and all its contents.
• rm -f file — force deletion without prompts.

⚠️ Caution! Files deleted via rm usually don't go to the trash. Make sure you specify the correct path.

rm oldfile.txt
rm -r old_dir/

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Step 3: Viewing and Editing Files

Sometimes you need to quickly view a file's contents or make edits.

Outputting Contents

• cat file — output the entire file to the terminal (suitable for small files).
• less file — page-by-page viewing (scroll with arrows, exit with q).
• head file — first 10 lines of a file.
• tail file — last 10 lines (useful for logs).

cat /etc/os-release
less /var/log/syslog
tail -f /var/log/auth.log   # monitor changes in real time

Editing

• nano file — simple text editor with prompts (ideal for beginners).
• vim file — powerful modal editor (requires learning but very efficient).

nano myconfig.conf
# In nano: Ctrl+O — save, Ctrl+X — exit

Step 4: Managing Processes

Processes are running programs. Knowing how to manage them is critical for system stability.

Viewing Processes

• ps — snapshot of processes (usually current user).
• ps aux — all system processes (columns: USER, PID, %CPU, %MEM, COMMAND).
• top or htop — interactive monitoring (real-time updates, sorting, termination).

ps aux | grep nginx   # find nginx processes
top                  # to exit — q

Terminating Processes

• kill PID — gently terminate a process by its ID (PID).
• kill -9 PID — force terminate (SIGKILL) if the process is unresponsive.

kill 1234            # graceful termination
kill -9 1234         # forceful
pkill firefox        # terminate all processes named firefox

Step 5: Searching and Filtering

When you have many files, search by name or content.

Finding Files

• find /path -name "filename" — search for files by name (supports wildcards *).
• find /path -type f — only files (-type d — directories).
• find /path -size +1M — files larger than 1 MB.

find /home -name "*.txt"
find /var/log -type f -mtime -7   # modified in the last 7 days

Searching Text Inside Files

• grep "pattern" file — find lines containing the pattern.
• grep -r "pattern" /dir — recursive search in a directory.
• grep -i "pattern" — case-insensitive.

grep "error" /var/log/syslog
grep -r "TODO" ~/projects/

Step 6: Getting Help

Don't memorize everything — Linux has excellent built-in documentation.

man — Manual Pages

man command shows the full manual page with description, options, and examples.

man ls
# Navigation: arrows, PageUp/Down, /text to search, q to exit

--help or -h

Quick help directly in the terminal.

ls --help
grep -h

whatis — Short Description

whatis ls
# Output: ls (1)               - list directory contents

Checking Your Results

After completing this guide, you should be able to confidently perform the following actions:

1. Open a terminal and run pwd — you'll see the current path.
2. Navigate to another directory with cd and verify with ls.
3. Create a file touch test.txt and a directory mkdir test_dir.
4. Copy a file cp test.txt backup/ and move it mv test.txt new.txt.
5. Output a file's contents cat /etc/os-release and find a process ps aux | grep bash.
6. Get help man cd and find a command whatis grep.

If all commands work without errors — you've mastered the basics!

Possible Issues

"Permission denied" Error

Cause: Insufficient permissions for the operation (e.g., writing to a system directory). Solution: Use sudo before the command (if you have administrator rights) or change to a directory where you have permissions (e.g., ~/).

sudo rm /etc/important.conf  # requires administrator password

"No such file or directory"

Cause: An incorrect path or filename was specified. Solution: Check the current directory (pwd) and file list (ls). Use absolute paths (/home/user/file) instead of relative ones.

"Command not found"

Cause: The command is not installed or there's a typo in the name. Solution: Check the spelling. Install the package via the package manager (e.g., sudo apt install package for Ubuntu/Debian).

Infinite Output in cat for Large Files

Cause: You're outputting a huge file (e.g., a binary or a multi-hundred MB log). Solution: Use less or limit the output (head, tail).

Unable to Terminate a Process

Cause: The process is ignoring the gentle SIGTERM signal. Solution: Use kill -9 PID (SIGKILL), but only if other methods fail — this is an emergency termination.