Basic Commands

Basic Commands

Add/Remove Programs

• dpkg -l | grep -i someapp - find package name
• apt-get update (fetch updates)
• apt-get upgrade (apply updates)
• see askUbuntu, What is the correct way to completely remove an application?
  • apt-get remove packagename → removes the binaries, but not the configuration or data files of the package. It will also leave dependencies installed with it on installation time untouched.
  • apt-get purge packagename or apt-get remove --purge packagename → will remove about everything regarding the package, but not the dependencies installed with it on installation. Both commands are equivalent.
    Useful when you want to 'start all over' with an application because you messed up the configuration. However, it does not remove configuration or data files residing in users home directories, usually in hidden folders there. There is no easy way to get those removed as well.
  • apt-get autoremove → removes orphaned packages, i.e. installed packages that used to be installed as an dependency, but aren't any longer.
• ask Ubuntu, How to uninstall a package installed from snapcraft?

Upgrade Programs

Sometimes need to know how a program was installed — Example for zoom:

• First, try which zoom or which zoom-client to get the path to the executable. Inspect the path root:
  • /snap was installed by Snap (Or the Ubuntu Software Center), then snap list | grep -i zoom to get full/correct Snap name
  • /usr/bin it was probably installed with apt or Synaptic — dpkg -l | grep -i zoom or apt policy zoom* will tell you more.
• Run the Synaptic Package Manager (sudo apt install synaptic) and look at the "Installed (Local or Obsolete)" filter
• Flatpak — check with flatpak list | grep -i zoom
• Ubuntu Make — check with umake --list-installed (For example, IDEs)

Create Users

• useradd is native binary compiled with the system
  • requires -m to create '/home/username' directory
• adduser is a perl script which uses useradd:
  • more user friendly and interactive than useradd
  • automatically creates '/home/username' directory

man page for adduser

adduser and addgroup add users and groups to the system according to options and configuration in /etc/adduser.conf.

They are friendlier front ends to the low level tools like useradd, groupadd and usermod programs, by default choosing policy conformant UID and GID values, creating a home directory with skeletal configuration, running a custom script, and other features.

adduser and addgroup can be run in one of five modes...

man page for useradd:

useradd is a low level utility for adding users. Administrators should usually use adduser.

GPU/NVDIA Commands

This section has been expanded and moved to NVIDIA Setup & Maintenance

Make the uploads folder writable

> cd /home/shanebow/public_html
> sudo chmod -R 775 uploads
> sudo chown shanebow uploads

Install node.js and PM2

> curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -
> curl -sL https://deb.nodesource.com/setup_10.x | sudo bash -
> sudo apt-get install -y nodejs
> node -v
v10.14.0
> sudo npm i -g npx
> sudo apt-get install -g pm2

Don't forget to make the server executable withsudo chmod 775 server.js

alias ll='ls -lsah --color=auto'
alias dc=docker-compose
alias d=docker

ip a