System

$EDITOR

1 min read · system

The System's default text editor can be defined within /etc/profile. It's given the variable EDITOR. Add these lines to /etc/profile.d/custom.sh: 1echo 'export EDITOR=vim' >> /etc/profile.d/custom.sh 2echo 'export VISUAL=$EDITOR' >> /etc/profile.d/custom.sh Then reload that profile with: 1source /etc/profile If you …

android

1 min read · system phone

mtpfs Start Install: 1yay -S simple-mtpfs List available phones: 1simple-mtpfs -l Make a mount point: 1mkdir phone Check your phone, and tell it to allow access to the USB. 1simple-mtpfs --device 1 phone Stop 1fusermount -u phone 2rmdir phone

Ansible Basics

2 min read · system ansible orchestration

Start Locally Start by doing normal actions on the computer. Say 'hello' to yourself: 1ansible --module-name=ping localhost Ansible takes a lot of information about each machine during setup: 1TMP=$(mktemp) 2ansible --module-name=setup localhost | tee $TMP 3less !$ If you have jq, you can pull out info: 1sed -i …

Ansible with Docker

2 min read · system ansible docker

'Docker module', you say? No need for that fancy stuff. We're just going to set up a couple of docker containers and connect to them like any other machine. Set up two containers: deb and arch, add them to an ansible hosts file, then do a 'ping' to see if they respond. Required Packages ansible jq docker Debian …

awk

2 min read · system .csv

Basics See a file's contents: Return full contents of a string: 1awk '{ print }' file Print the first and second column: 1awk '{print$1$2}' Return every line with the word 'the' (like grep): 1awk '/the/{print}' file Print everything containing a lowercase letter: 1awk '/[a-z]/{print}' file Same with numbers [0-9], or …

character-encoding

1 min read · system encoding

Convert a text file from one encoding type to another with: 1iconv -f ascii -t utf8 oldfilename > newfilename Available options are: ISO-8859-15 UTF-8 ASCII Lots more Generate a full list of encoding types available with: 1iconv -l

Clean Your Downloads

1 min read · system tmpfs

'Downloads` directory always too full of crap? Make it a temporary filesystem! Everything will be deleted whenever you reboot. 1rm -rf ~/Downloads # Be brave! 2mkdir Downloads 3cp /etc/fstab /tmp/ 4echo "tmpfs $HOME/Downloads tmpfs defaults,size=1G 0 0" | sudo tee -a /etc/fstab 5sudo systemctl daemon-reload # Ignore …

deduplicate

1 min read · system deduplicate maintenance storage

rdfind: find duplicate files, then delete them, or turn them into links. Ask if a directory has duplicates (rdfind will not delete anything): 1rdfind $dir 2$EDITOR results.txt Replace the duplicated files with hard links. 1rdfind -makehardlinks true $dir

fstab

1 min read · system disk

Basics The ordering of /etc/fstab is disk mount point filesystem type options dump pass Example: 1UUID=877f14e8-4738-46b0-884f-ba330dad1a7d /mnt/biggie ext4 nofail,rw,relatime 0 2 2 3UUID=B21648C416488AF5 /mnt/share ntfs nofail,rw,nosuid,nodev,user_id=0,group_id=0,allow_other,blksize=4096 0 0 5: Dump Ignore this …

kernel modules

1 min read · system

Kernel modules live in lib/modules/$(uname -r) Change Load them with 1modprobe ath9k Or remove one with 1modprove uvcvideo The PC's irritating speaker beep can be really annoying. Disable it with: 1modprobe -r pcspeaker Permanently disable a module by blacklisting it in /etc/modprobe.d: 1echo 'blacklist pcspkr' > …