ubuntu-cheatsheet

Ubuntu commands for people who don't know Linux

System Management

• Restart the machine: sudo shutdown -r now

User Management

• Create a new user: useradd {username}

Disk Management

• Checking for disk space on available volumes: df -h command
• Check for size of folders in current working directory: du -h --max-depth=1

File System

• Create .tar.gz / .tgz files: tar -czvf {output.tgz} {folder}
• Extract .tar.gz / .tgz files: tar -xzvf {input.tgz} {path}
• Create .zip files: zip -r {output.zip} {folder}
• Extract .zip files to directory: unzip {input.zip} -d {folder}
• Watch a log file real-time: tail -f {file}
• Find files containing text: grep -Rl {search} {path} or case insensitive grep -Rli {search} {path}
• Download a file from the internet: wget {url}
• Back up your stuff locally: rsync {source} {destination}
• Back up your stuff to another server: rsync -avz -e ssh {path} {user}@{host}:{path}

File Permissions

• Make a file executable: chmod +x {filename}

Environment Variables

• Inspect the current PATH variables: echo $PATH
• Append directory to the existing PATH: export PATH=$PATH:/path/to/binary
• Declare a new environment variable: export {variable}=/path/to/binary
• Edit system-wide environment variables: nano /etc/environment
• Create an alias for a command: nano ~/.bash_aliases followed by alias {alias name}='{command}'

Process Management

• Kill a process: kill {pid}
• See all running processes: ps aux
• Get PIDs of running processes under a specific name: ps aux | grep {name} or ps aux | grep {name} | awk '{print $2}'

Machine Properties

• Modify the host name: sudo nano /etc/hostname
• Set a static IP address: sudo nano /etc/network/interfaces
• Modify hosts: sudo nano /etc/hosts

Cron Jobs

• Check existing cron jobs: crontab -e

Networking

• What IP adress is assiged to me? ifconfig
• What TCP/IP ports are open and what programs are listening on them? lsof -i -P (needs to have lsof installed and be run as root)
• Where do I configure my network interfaces? vi /etc/network/interfaces then run ifdown <interface> and then ifup <interface>
• What are the details of a specific network interface? iwlist <interface> scan
• Connect to a specific wireless network for a given interface? iwconfig <interface> essid "<ssid name>"
• Get an IP address assigned from a router? dhclient <interface>
• How do I list all NAT rules? iptables -L
• What are all of the available network devices for this machine? lspci

Databases

• How do I install MySQL? Stab a fork in your eye and install Postgres instead.