linux

Command reference

Command Keywords/Description
cat /proc/cmdline Commandline options kernel was started with
lsb_release -a Distribution version details
uname -a Kernel details
sudo dmidecode -s system-serial-number Machine serial number
journalctl --system -S "2024-03-22 14:00" System log (add -no-tail when piping to something)
edid-decode /sys/class/drm/card0-eDP-1/edid Get display details
sudo lshw -C memory Memory (RAM) details
sudo smartctl -a /dev/nvme0 NVMe SSD details
lsblk Block device e.g. disk details
lscpu CPU details
lsusb USB bus details
sudo hwinfo Firehose of hardware info
df -H Disk space stats in human friendly format
sudo systemctl status <service name> Service status
sudo systemctl start|stop|enable <service name> Enable, start and stop to control services
cat /sys/power/mem_sleep Sleep mode details
cat /sys/power/disk What the kernel should do after creating a hibernation image
sudo systemctl mask hibernate.target hybrid-sleep.target Mask sleep states
sudo systemctl status sleep.target suspend.target hibernate.target hybrid-sleep.target Examine masked states
lpstat Get printer details
lp print files
echo $XDG_CURRENT_DESKTOP Current window manager
sudo vi /etc/default/grub Edit GRUB configuration
sudo update-grub Write out GRUB configuration (Ubuntu)
sudo grub2-mkconfig -o /boot/grub/grub.cfg If update-grub is not available
avahi-browse -a Find devices via mDNS
avahi-resolve-address 192.168.8.1 Find mDNS name for given address
getent hosts 192.168.8.1  
apt show X Show details (including size) of a package
ifconfig Networking interface configuration
mtr 8.8.8.8 Trace route to host
ls -R List directory contents recursively
cmd > std.out 2> std.err Redirect stdout of cmd to std.out and stderr to std.err
cmd 2> out.txt Redirect stdout and stderr to out.txt
du -sh <directory> Size of directory
df -H Used and free sizes of all mount points
find . -type d -empty -print Find and print all empty directories
find . -type d -empty -delete Delete all empty directories
find Takeout -name "*.json" -type f -print Find and print all files with given extension
iperf3 -s Start iperf3 server on target machine “hostname”
iperf3 -c hostname connect to “hostname” and determine speed of connection
xhost + local:user2 grant “user2” access to your display on the
(non-network) local machine  
su - user2 open a login shell as “user2”
pdfjam <input file> <page ranges> -o <output file> Extract pages from pdf

mDNS: Local hostname resolution

Multicast DNS (mDNS) enables machines to resolve devices on the LAN using <hostname>.local scheme. The implementation for Linux is Avahi. Ubuntu installs this automatically, but some other distributions, like openSUsE, do not. The arch wiki page is a great resource for setting it up yourself.

ControlMaster: persist/reuse ssh connections e.g. for rsync

https://man.openbsd.org/ssh_config.5#ControlMaster

Example:

# in ~/.ssh/config
ControlMaster auto
ControlPath ~/.ssh/control:%C
ControlPersist 5m

tmux

Add setw -g mouse on in ~/.tmux.conf to enable scrollback with mouse scroll.

Synology NAS

Vi(m) / NeoVim

.vimrc
Config files

Command Keywords/Description
gq} Wrap paragraph
34% Go to 34% of the file
GitGutterStageHunk Stage the hunk the cursor is on

Auto save for markdown files

In .vimrc/init.vim

" Auto save for markdown files in insert mode
autocmd BufNewFile,BufRead *.md :autocmd TextChangedI <buffer> if &readonly == 0 | silent write | endif

Refs: [1], [2]

Copy-paste

Check if compiled with clipboard support

vim --version | grep clipboard

# or
:echo has('clipboard'))

Paste from clipboards (When compiled with +clipboard option

"+p
"*p

Copy large number of lines

  1. In command mode mark starting line: ma
  2. In command mode, at last line, yank from mark: y`a

This can be used to delete too d`a

Tabs

Open file in new tab

:tabedit <file>

# Goto tab
[tab number]gt

# e.g. 2gt will go to second tab

Esc ape from insert mode is slow

https://vi.stackexchange.com/a/20220

set tttimeoutlen=5

Builtin file explorer: netrw

# Start with
:Explore
:Sexplore
:Vexplore

Refs: [1], [2]

Color schemes

# See available
:colorscheme [space] [CTRL+D]

The built in colorschemes are in /usr/share/vim/vim90/colors/

Plugins

  1. git gutter
  2. A.L.E
  3. NERDTree Actually, the “builtin” explorer netrw is good enough for me.

Topic sheets

  1. Gnome
  2. Utilities
  3. Bash multiple history files
  4. Multiple Dosbox configurations
  5. Writing

Software I use

General

sudo apt install git flatpak simple-scan

Flatpaks

flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo

flatpak install flathub org.mozilla.firefox
flatpak install flathub io.github.dosbox-staging
flatpak install flathub net.sf.VICE

Flatpack commandlines

flatpak run --filesystem=/home/kghose/RetroComputing/dosbox io.github.dosbox-staging

flatpak run --filesystem=/home/kghose/RetroComputing/c64/ net.sf.VICE

flatpak run org.mozilla.firefox

Examine permissions

flatpak info --show-permissions org.mozilla.firefox
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