Git

 
 remote=origin 
 branch=master 
 
 # get current branch name only 
 git rev-parse --abbrev-ref HEAD 
 
 # discard all local work on the branch 
 git reset --hard $remote/$branch 
 
 # zip git archive based on current HEAD 
 git archive --format zip -o "archiveName.zip" HEAD # could be a commit ID too 
 
 # get absolute directory of repository root 
 git rev-parse --show-toplevel 
 
 # get current commit ID 
 git rev-parse HEAD 
 
 # "Squash" all changes on a branch, can be used with master 
 git checkout --orphan new-${branch} ${branch} # create orphan 
 git commit --message "squash" # commit it 
 git branch -M new-${branch} ${branch} # force-rename on top of old 
 

JQ

 
 # "..." is meant to indicate some source of valid json over stdin 
 
 # Get a json list of all keys on an object 
 ... | jq 'keys' 
 

YQ

There's also a tool called "yq", there seem to be two variants floating around.

One is a simple python wrapper around jq

Another is a full-featured, generic configuration-format stream editor. It's called go-yq in archlinux repos.

Connman

 
 # connmanctl requires the connmand daemon to be running. 
 # Any of these commands can be run from within the connmanctl shell, 
 # which (incidentally); has nice things like autocomplete. 
 
 # Get help. 
 connmanctl help 
 
 # summary list of "devices", the names of which are used for further commands 
 connmanctl technologies 
 
 # scan on device named "wifi". This gathers a list of access points 
 connmanctl scan wifi 
 
 # Actually list available access points, SSIDs, etc 
 # SSIDs are given in hexadecimal encoded form, thus accommodating weird names 
 connmanctl services 
 
 # To connect to a protected access point: 
 # 1. drop into interactive mode 
 # 2. Enable the agent 
 # 3. Initiate connection -- connmanctl will prompt you for passphrase 
 connmanctl 
 ... agent on 
 ... connect wifi_abcdef0123456789_managed_psk 
 

SSH

 
 # Change default key password 
 ssh-keygen -p 
 

inotify

 
 # continually watch a file, performing some action when it is modified 
 inotifywait -q -e modify my_file.txt | while read DIRECTORY EVENT FILE; do 
 ... 
 done 
 
 # continually watch an directory tree, fire when creating, modifying, deleting 
 inotifywait -q -r -e modify,delete | while read DIRECTORY EVENT FILE; do 
 ... 
 done 
 

Pacman

Of course there is the Pacman Rosetta