Linux cheat sheet

Linux commands I frequently use:

1. Change to root (on Ubuntu): sudo -i
2. uname -r 
3. sudo apt update && sudo apt upgrade
4. Show processes whose name contains a specific string: ps -ef | grep <string>
5. Forcefully kill process: pkill -f <process name>
• Example: pkill -f update-notifier
6. Run process in background: ./<process name> &
7. Show network card info: ifconfig
8. Show resource usage of running processes: top, htop
9. Reverse-i-search with ctrl+r
10. Change MAC address: sudo ifconfig enp2s0 hw ether 64:00:6a:28:fa:ac
11. Ubuntu: Allow GUI root login
12. Enable SSH to root user by adding the line PermitRootLogin yes to /etc/ssh/sshd_config
13. Enable receiving UDP packets 
1. Disable firewall completely: sudo ufw disable
2. Or you can allow for example on port 5000: sudo ufw allow from any to any port 5000 proto udp
14. Create image of USB with size of 8GB: dd if=/dev/sdb of=/home/myimage.img bs=1G count=8 status=progress

Tools:

1. sudo apt install net-tools
2. sudo apt install build-essential
• gcc --version
• make --version
3. Eclipse IDE for C++
1. In a project, when you remove a folder and copy another version of the same folder but with fewer files, during build, you might get the error "No rule to make target…". Right click on the project and select refresh, this rebuilds the index. Now you can build successfully.
4. To use psftp from another Windows computer for file transfer: sudo apt install openssh-server
5. sudo apt install rt-tests
• Sample usage: cyclictest l100000 -t 8 p95
6. sudo apt install htop
7. For remote connection from Windows: 
• sudo apt install xrdp
• sudo systemctl restart xrdp
• Note that you have to be logged out from Ubuntu for remote from Windows to work.