Introduction

The Linux terminal is your gateway to the operating system. Here's a breakdown of essential commands that every beginner should master.

ls — List Directory Contents

Lists files and folders in the current directory.

ls              # basic listing
ls -l           # long format (permissions, size, date)
ls -a           # show hidden files (those starting with .)
ls -la          # long format + hidden files
ls -lh          # long format with human-readable sizes

The output of ls -l shows: file type + permissions, link count, owner, group, size, modification date, and name.

cd — Change Directory

Moves you between directories.

cd /home/user   # go to an absolute path
cd Documents    # go into a subdirectory (relative path)
cd ..           # go up one directory
cd ~            # go to your home directory
cd -            # go to the previous directory

cd / — Root Directory

/ is the root of the entire Linux filesystem — the topmost directory. Everything on your system lives under /.

cd /            # jump to the root of the filesystem
ls /            # see top-level directories like /bin, /etc, /home, /var, /usr

Key directories under /:

  • /bin & /usr/bin — essential user binaries (commands)
  • /etc — system configuration files
  • /home — user home directories
  • /var — variable data (logs, databases)
  • /tmp — temporary files

mkdir — Make Directory

Creates new directories.

mkdir myfolder           # create a single directory
mkdir -p a/b/c           # create nested directories (parent chain)
mkdir dir1 dir2 dir3     # create multiple directories at once

The -p flag is especially useful in scripts — it creates parent directories as needed and won't error if they already exist.

touch — Create Empty Files / Update Timestamps

Creates an empty file or updates the timestamp of an existing one.

touch file.txt           # create a new empty file
touch existing.txt       # update its last-modified time to now
touch a.txt b.txt c.txt  # create multiple files

Useful for creating placeholder files, log files, or forcing file timestamp updates.

rm — Remove Files and Directories

Permanently deletes files. There is no Trash bin — use with care.

rm file.txt              # delete a file
rm -i file.txt           # prompt before each deletion (safe mode)
rm -r myfolder           # recursively delete a directory and its contents
rm -f file.txt           # force delete (no prompt, even if write-protected)
rm -rf myfolder          # 🔥 recursive + force — extremely powerful, be very careful

Warning: rm -rf / would attempt to delete your entire system. Never run this unless you know exactly what you're doing (and even then, don't).

mv — Move or Rename Files

Moves a file to a new location, or renames it within the same directory.

mv file.txt /tmp/        # move file.txt into /tmp
mv oldname.txt newname.txt  # rename a file
mv file1.txt dir/        # move file1.txt into dir/
mv -i file.txt dir/      # prompt before overwriting any existing file

mv is also the standard way to rename files and directories in Linux.

vim — Terminal Text Editor

A powerful modal text editor that runs in the terminal.

vim file.txt             # open or create a file in vim

Vim Modes (essential)

| Mode | What it does | |------|-------------| | Normal | default — navigate, copy, paste, delete (press Esc to return here) | | Insert | type text (press i to enter) | | Visual | select text (v for character, V for line) | | Command | run commands like save/quit (: to enter) |

Vim Survival Guide

i               # enter Insert mode (start typing)
Esc             # return to Normal mode
:w              # save the file (write)
:q              # quit vim
:wq             # save and quit
:q!             # quit without saving (force)
dd              # delete the current line
yy              # copy (yank) the current line
p               # paste below the cursor
/searchterm     # search for "searchterm" in the file
n               # go to next search match
u               # undo
Ctrl + r        # redo

ifconfig — Network Interface Configuration

Shows and configures network interfaces. On modern Linux, ip is the replacement, but ifconfig is still widely used.

ifconfig                # show all active network interfaces
ifconfig -a             # show all interfaces (including inactive)
ifconfig eth0           # show details for a specific interface
sudo ifconfig eth0 down     # take an interface offline
sudo ifconfig eth0 up       # bring an interface online

Typical output includes: IP address (inet), netmask, broadcast address, MAC address (ether), and packet stats (RX/TX).

Note: You may need to install net-tools to get ifconfig: sudo apt install net-tools

nslookup — DNS Lookup

Queries DNS servers to resolve domain names to IP addresses (and vice versa).

nslookup google.com          # get the IP address of google.com
nslookup 8.8.8.8             # reverse lookup — find the domain for an IP
nslookup google.com 1.1.1.1  # query a specific DNS server (Cloudflare)
``\)

Output shows the DNS server used, the resolved IP address (A record), and sometimes alias names (CNAME).

Useful for debugging DNS issues like "why can't my browser reach this website?"

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## Summary Cheatsheet

| Command | What it does |
|---------|-------------|
| `ls` | List files |
| `cd` | Change directory |
| `mkdir` | Create a directory |
| `touch` | Create/update a file |
| `rm` | Delete files (permanent!) |
| `mv` | Move or rename files |
| `vim` | Edit files in terminal |
| `ifconfig` | Show network interfaces |
| `nslookup` | Query DNS records |

Practice these in your terminal daily and they'll become second nature in no time.