GNU/Linux

Determining IP Address on Ubuntu

ip addr show

Finding out If a Command Is Available to Run on Ubuntu

compgen -c | grep <COMMAND>

Disk Usage

In current directory: du -h . --max-depth=1 on Ubuntu or du -hd1. on macOS

Installing GNU/Linux on an Apple Computer

On Mac, no screen when booting installation: highlight the boot option, press e, add radeon.modeset=0 to the menu that pops up, then press enter. I spent ages to arrive at that!!

Resources:

trash-cli not going to ~/.local/share/Trash/files

It is probably going to /files/scratch/.Trash

Using Gnome Settings in i3

XDG_CURRENT_DESKTOP=Gnome && gnome-control-center

Enabling Compose Key for Typing Accented Letters

Often, in a desktop environment, there is a way to do this through the settings. Otherwise,

In ~/.Xmodmap, add

keycode 108 = Multi_key Alt_R Meta_R Alt_R Meta_R

May need to change the keycode depending on the keyboard; see https://wiki.archlinux.org/title/Keyboard_input#Identifying_keycodes_in_Xorg.

To source this, run xmodmap ~/.Xmodmap. To use with i3, add exec --no-startup-id "xmodmap ~/.Xmodmap" to \~/.config/i3/config.

Kernel Module Not Loaded on Startup

Check it is not blacklisted. You can run journalctl -b and search for the module, and it might say it was blacklisted, "deny-listed", etc. There may be an entry in /etc/modprobe.d/ blacklisting it. If not, there may also be one in /usr/lib/modprobe.d.

Network Interface Not Showing

If the network interface does now show when running ip link, try running lspci -k to see find the relevant kernel module. You can manually load this kernel module by running modprobe <module> as root. If this works, it is likely that the module is blacklisted from loading on startup; see Kernel Module Not Loaded on Startup

Screen Order for Dual Monitor

See which displays are connected using xrandr. Say you want display DP-2 to be the primary display, which is to the left of DP-0, run xrandr --output DP-2 --primary --auto --left-of DP-0. To save this configuration by running this on startup, put it in /.xprofile.

No Display After pacman -Syu with Nvidia Graphics

This can happen if you installed the Nvidia driver from the Nvidia website rather than using Pacman, as described here. Uninstall the existing Nvidia drivers using the the commande here, then reinstall using pacman -S nvidia, and pacman -S nvidia-utils.

gtk-WARNING **: cannot open display

Install an X server. E.g. on macOS, brew install xquartz (then reboot).

"Unable to Verify Startup Disk" Error When Trying to Boot Linux on Mac

Press CMD+R during startup, then under Utilities, choose Startup Security Utility. Set Secure Boot to No Security, and set Allowed Boot Media to Allow booting from external or removable media.