Shell One-Liners with Quick Search

🧹 Find and delete all empty directories

find . -type d -empty -delete

filescleanupfind

📦 Find the 10 largest files in the current folder

du -ah . | sort -rh | head -n 10

filesdisk usagesorting

📝 Batch rename file extensions, for example from .txt to .md

rename 's/\.txt$/\.md/' *.txt

renamefilesbatch

💾 Create a quick backup of a file

cp file.txt{,.bak}

backupcopyfiles

🔢 Extract unique lines from a file and count occurrences

sort file.txt | uniq -c | sort -nr

textuniqsorting

🪵 Follow logs in real time and highlight the word Error

tail -f access.log | grep --color=always "Error"

logstailgrep

🧽 Remove duplicate lines without sorting and preserve order

awk '!visited[$0]++' file.txt

awktextdedupe

🔁 Replace all occurrences of one phrase with another in many files

sed -i 's/old/new/g' *.txt

sedreplacetext

🚪 Check which process is using a given port, for example 8080

lsof -i :8080

portprocesssystem

📊 Show the most frequently used commands from shell history

history | awk '{print $2}' | sort | uniq -c | sort -rn | head -10

historyanalyticsterminal

🌍 Start a quick HTTP server in the current folder using Python 3

python3 -m http.server 8000

httppythonserver

🌐 Check your external IP address

curl ifconfig.me

networkipcurl

🌿 Delete all local Git branches except main

git branch | grep -v "main" | xargs git branch -D

gitcleanupbranches

🔎 Find text in all project files with line numbers

grep -rnE "search_phrase" .

grepsearchproject

📦 Clear the npm cache when node modules start acting suspicious

npm cache clean --force

npmcachenode

🧠 Re-run the last command with sudo

sudo !!

sudoterminalshortcut

📄 Save command output to a file and still display it on screen

ls -la | tee list.txt

teeoutputfiles

🏗️ Create a whole project folder structure in one shot

mkdir -p project/{src,bin,doc,tests}

mkdirscaffoldproject

💥 Kill a process by name instead of hunting for the PID

pkill -f process_name

processpkillsystem

🔐 Show file permissions in numeric form, for example 755

stat -c "%a %n" *

permissionsstatfiles

🧷 Check which TCP and UDP ports are listening, including processes

sudo ss -tulpn

networkportsss

🌍 Quickly check your external IP address

curl -s https://ifconfig.me

ipcurlnetwork

🛰️ Trace a packet route the modern way with mtr

mtr google.com

routingmtrdiagnostics

🧩 Display all network interfaces in a readable short format

ip -brief address show

interfacesipsystem

🚪 Test a specific port on a remote server

nc -zv 192.168.1.1 80

portnetcatremote

📡 Scan your local network for active devices

nmap -sn 192.168.1.0/24

nmapscanlan

🧾 Find active IP addresses on the network without using nmap

arp -a

arplandiscovery

🧭 Check DNS records such as A, MX, and TXT for a domain

dig google.com ANY +noall +answer

dnsdigdomain

🛣️ Display the routing table

ip route show

routegatewaynetwork

👀 Sniff live HTTP headers going through the network

sudo tcpdump -A -s 0 'tcp port 80'

tcpdumptraffichttp

📈 Monitor live traffic on a specific network interface

nload eth0 # or iftop

monitoringnloadiftop

🐷 See how much network traffic each process is using

sudo nethogs

processesbandwidthnethogs

📡 Check HTTP response headers without downloading the body

curl -I https://google.com

curlhttpheaders

📂 Start a quick file server in the current folder on port 8000

python3 -m http.server 8000

httppythonserver

⬇️ Download a file and save it using the original filename

curl -O https://example.com/file.zip

downloadcurlfiles

🔄 Restart a network interface such as eth0

sudo ip link set eth0 down && sudo ip link set eth0 up

interfacerestartnetwork

🧼 Flush the DNS cache when using systemd-resolved

sudo resolvectl flush-caches

dnscachesystemd

🚦 Find your default gateway

ip route | grep default

gatewayroutenetwork

📉 Display error statistics on network interfaces

netstat -i

interfaceserrorsnetstat

🕵️ Check who owns an IP address or domain

whois 8.8.8.8

whoisownershipsecurity