My CLI cheat-sheet

cli.md

# Command Line cheatsheet

Commands

Cheat Sheets

Navigate

Command	meaning	example
pwd	Print work directory
ls	list files in current directory
ls -a	List all files, including hidden files
ls -l	List files in current directory as a list
ls -la	List all files in current directory as a list
cd /	Change directory to root
cd ~	Change directory to home
cd -	go back to the most recent dir you've been in
history	display past commands

Files management

Command	meaning	example
cp [origin] [destination]	copy	cp text.txt .
mv [origin] [destination]	move (and rename)	cp text.txt .
rm -rf folder_or_filename	remove folder_filename forcefully recursively
defaults write com.apple.finder AppleShowAllFiles TRUE	Shows hidden files in Finder
which python3	Shows you where the python command is located
python -V or python --version	Shows you the version of Python

Files editing

| touch scriptname.sh | create shell script scriptname.sh | | | echo "hello" > file.txt | print "hello" to file.txt | | | cat filename | display contents of in terminal| | | head filename | print first x lines of filename | | | tail filename | print last x line of filename | | | tail -f your.log | Open a live version of the file your.log in the terminal | history > file1.txt | replace contents of file1.txt with history | | | history >> file1.txt | append contents of file1.txt with history | | | history \ grep "git" > file1.txt | Find the word "git" in my history and replace the content of file1.txt with the result| |

Find

Command	meaning	example
find . -name "file*"	find files and folders with the characters "file" AS part of the name
find / -name "postgresql.conf"	find the file 'postgresql.conf' recursively from the root folder

Task management

Command	meaning	example
lsof -i tcp:8000	List open files on tcp port 8000
kill -9 pid	kills the process with the pid
lsof -t -i tcp:8000 | xargs kill -9	kill all processes on port 8000
killall Finder	Restarts the Mac Finder program
ps aux	report a snapshot of the current processes. a = show processes for all users, u = display the process's user/owner, x = also show processes not attached to a terminal
top	Show all the running processes within your Linux environment

Permissions

Command	meaning	example
chmod 124 filename.ext	change permissions - owner, user, guest

User

| echo $USER | print the username to the console | | whoami | Shows your user | | sudo su | Change to root user |

Update

Command	Description
sudo apt update	Fetches the list of available updates
sudo apt upgrade	Installs some updates; does not remove packages
sudo apt full-upgrade	Installs updates; may also remove some packages, it needed
sudo apt autoremove	Removes any old packages that are no longer needed
reboot	Reboot computer

Background tasks

Commmand	Description
python3 script.py &	Run python script in the background
nohup python3 script.py &	Run python script in the background and detach from session

Postgres

Commmand	Description
sudo service postgresql stop	Stop postgres database
sudo service postgresql start	Star postgres database

Networking

Command	Description
curl ifconfig.me	Get own ip number
curl https://freegeoip.app/xml/143.204.247.98	Get the geolocation of an ip number using the freegeoip service
curl https://freegeoip.app/xml/bitmex.com	Get the geolocation of an ip number
dig 143.204.247.98	DNS lookup utility
dig bitmex.com	DNS lookup utility
traceroute 143.204.247.98	print the route packets take to network host
traceroute bitmex.com	print the route packets take to network host

CLI options

option	Effect
-r	recursively
-m	message

Customization

Change ~/.bash_profile, .profile or ~/.zscrc to set custom command aliases

alias	Resolves to	Description
zshcf	vim ~/.zshrc	Edit zsh profile settings

Permissions

drwxr

rwx = Read Write Execute

Directory	Owner	Group	User
-	- - -	- - -	- - -
d	rwx	rwx	rwx
1	421	421	421

Examples

chmod 777 = read(4), write(2) and execute(1) right for owner(4), group(2) and user(1)
chmod 777  = give owner, group and user read, write and execute rights
chmod 444 = give owner, group and user read access
chmod 400 = give owner read access and all others no rights

Shell Scripting

Everything is a file!

#!/bin/bash/
echo "starting script...
touch ~/Desktop/virus"
echo "creating virus"
echo "=============="
echo "adding to virus..."
find /Users/vkng/Dropbox/99_code/Python/CodingNomads -name "*week*" >> ~/Desktop/virus
open ~/Desktop/virus

#!/bin/bash/ is called the shbang