Terminal Tuesday ‼️

Ulfnic · January 6, 2021, 3:49pm

community@dlnforum:~$ chmod +x ~/tt.sh && ~/tt.sh
▄▄▄▄▄▄▄▄ .▄▄▄  • ▌ ▄ ·. ▪   ▐ ▄  ▄▄▄· ▄▄▌         
•██  ▀▄.▀·▀▄ █··██ ▐███▪██ •█▌▐█▐█ ▀█ ██•         
 ▐█.▪▐▀▀▪▄▐▀▀▄ ▐█ ▌▐▌▐█·▐█·▐█▐▐▌▄█▀▀█ ██▪         
 ▐█▌·▐█▄▄▌▐█•█▌██ ██▌▐█▌▐█▌██▐█▌▐█ ▪▐▌▐█▌▐▌       
 ▀▀▀  ▀▀▀ .▀  ▀▀▀  █▪▀▀▀▀▀▀▀▀ █▪ ▀  ▀ .▀▀▀        
▄▄▄▄▄▄• ▄▌▄▄▄ ..▄▄ · ·▄▄▄▄   ▄▄▄·  ▄· ▄▌    ▄▄ ▄▄ 
•██  █▪██▌▀▄.▀·▐█ ▀. ██▪ ██ ▐█ ▀█ ▐█▪██▌    ██▌██▌
 ▐█.▪█▌▐█▌▐▀▀▪▄▄▀▀▀█▄▐█· ▐█▌▄█▀▀█ ▐█▌▐█▪    ▐█·▐█·
 ▐█▌·▐█▄█▌▐█▄▄▌▐█▄▪▐███. ██ ▐█ ▪▐▌ ▐█▀·.    .▀ .▀ 
 ▀▀▀  ▀▀▀  ▀▀▀  ▀▀▀▀ ▀▀▀▀▀•  ▀  ▀   ▀ •      ▀  ▀ 
Make your own text art: "https://patorjk.com/software/taag/#f=Elite&t=Terminal%0ATuesday !!"

Rule 0: Break the rules.
Rule 1: You can install any brew you want… as long as it can run in a virtual terminal.
Rule 2: No one should need to tesseract your screenshot.
Rule 4: If Shell were a breakfast cereal, which fun scripts/tips would be on the back?
Rule 8: https://wiki.archlinux.org/
Rule 15: echo "enoemos esirprus" | rev
Rule 32: Suggest how people could make their code better.
Rule ∞: Some things can’t be done in terminal.
Rule declare -A arr[∞]=16;echo ${arr[∞]}: The last rule is false.

Ulfnic · December 7, 2020, 3:48pm

Something I learned recently…

0 can be used as a shorthand for localhost.

Examples:
ping 0
curl 0 # Outputs self-hosted site among other things.
ssh -L 5900:0:5900 USER@ADDR # Local forwarding of VNC port over SSH

MarkofCain · December 7, 2020, 8:55pm

I knew that I could reach the local host in three different ways:

localhost
127.0.0.1
0.0.0.0

Thanks for the shortcut. Now I have a fourth.

BTW the shortcut 0:some_port works in a browser that doesn’t have “search from the address bar” (omnibox) enabled.

esbeeb · December 7, 2020, 11:45pm

Is this where to post the sexiest terminal? The hot red LED’s of the “6802 Serial Terminal” are a contender…

Ulfnic · December 13, 2020, 7:46pm

Getting your public IP in terminal:

Using curl

curl ifconfig.me
curl ifconfig.co
curl icanhazip.com
curl ipecho.net/plain
curl bot.whatismyipaddress.com
curl https://diagnostic.opendns.com/myip
curl http://checkip.amazonaws.com
curl http://whatismyip.akamai.com
curl icanhazip.com
curl https://ipinfo.io/ip
curl -s https://checkip.dyndns.org | sed -e ‘s/.Current IP Address: //’ -e 's/<.$//’

Using the lynx terminal Web browser

lynx -dump ifconfig.me | grep ‘IP Address’

Using wget

wget -q -O - ifconfig.me
# -q for quiet
# -O - to output to terminal

Using DNS lookup through host

host myip.opendns.com resolver1.opendns.com | grep “Address:” | awk ‘{print $2}’
(Seems to only return X-forwarded so it can be innacurate)

Getting your IP’s geolocation:

curl ipinfo.io
curl ipinfo.io/`wget -q -O - ifconfig.me`
curl http://api.geoiplookup.net/?query=`wget -q -O - ifconfig.me`
curl https://freegeoip.app/xml/`wget -q -O - ifconfig.me`
curl https://freegeoip.app/csv/`wget -q -O - ifconfig.me`
curl https://freegeoip.app/json/`wget -q -O - ifconfig.me`

MarkofCain · December 14, 2020, 10:54pm

beautiful. These will go into my “commands file.” That’s a file I keep of cli commands that I don’t need to know every day – but need them from time to time. It’s just a text file that has the command with a short description. Then occasionally at times when I waiting for something to start, I will just read through the file and keep those commands refreshed. Thanks for the new content.

esbeeb · December 15, 2020, 1:23pm

I have one of those too.

Ulfnic · December 16, 2020, 2:21pm

NGINX script for making your own public IP API in the cloud like the ones above:

location /ip {
    default_type text/plain;
    return 200 $remote_addr;
}
location /ip_json {
    default_type application/json;
    return 200 "{\"ip\":\"$remote_addr\"}";
}

From scratch:

# Fedora/CentOS/RHEL:
sudo dnf install nginx -y
sudo nano /etc/nginx/nginx.conf

# Debian/Ubuntu:
sudo apt install nginx -y
sudo nano /etc/nginx/sites-available/default

# Paste inside the "server {" encapsulation:
	location /ip {
		default_type text/plain;
		return 200 $remote_addr;
	}
	location /ip_json {
		default_type application/json;
		return 200 "{\"ip\":\"$remote_addr\"}";
	}
# Save and exit

sudo systemctl start nginx
curl 0/ip # Test
curl 0/ip_json # Test
sudo systemctl reload nginx # If you need to apply changes

# From your local machine:
curl MY_SERVER_IP_HERE/ip # Test

# Please ask for finer grained instructions.

PatPlusLinux · December 15, 2020, 4:10pm

Unlike this post, that’s value added.

esbeeb · December 16, 2020, 9:13pm

Cross-post

rastacalavera · December 16, 2020, 10:51pm

It’s Wednesday but I’ve been using the terminal a lot recently to edit mp3 files! I have been using mp3cut to trim up the DLN file system talks from previous episodes. I find this is quicker than using audacity!
It is really nice to have a tool like this and clear documentation that provides example use cases. +1 As you can see from my history, I had to play a bit to get the hang of it

  127  mp3cut -o media.mp3 -t 01:00:40-01:02:44 190.mp3
  128  mp3cut -o media.mp3 -t 01:00:59-01:02:44 190.mp3
  129  mp3cut -o media.mp3 -t 01:01:10-01:02:44 190.mp3
  130  mp3cut -o media.mp3 -t 01:01:21-01:02:44 190.mp3
  131  mp3cut -o media.mp3 -t 01:01:21-01:02:46 190.mp3
  132  mp3cut -o opt.mp3 -t 47:36-51:08 191.mp3
  133  mp3cut -o opt.mp3 -t 47:48-51:08 191.mp3
  134  mp3cut -o opt.mp3 -t 47:47+500-51:08 191.mp3
  135  mp3cut -o opt.mp3 -t 47:46+500-51:08 191.mp3
  136  mp3cut -o proc.mp3 -t 01:09:48-01:08:50 192.mp3
  137  mp3cut -o proc.mp3 -t 01:09:48-01:11:50 192.mp3
  138  mp3cut -o proc.mp3 -t 01:10:10-01:11:50 192.mp3
  139  mp3cut -o proc.mp3 -t 01:10:13-01:11:50 192.mp3
  140  mp3cut -o proc.mp3 -t 01:10:13+500-01:11:50 192.mp3
  141  mp3cut -o proc.mp3 -t 01:10:13+400-01:11:50 192.mp3
  142  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:50 192.mp3
  143  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:30 192.mp3
  144  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:46 192.mp3
  145  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:47 192.mp3
  146  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:50+800 192.mp3
  147  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:44+800 192.mp3
  148  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:43 192.mp3
  149  mp3cut -o proc.mp3 -t 01:10:13+900-01:11:43+800 192.mp3

esbeeb · December 16, 2020, 11:58pm

Check out EDEX-UI:

Ulfnic · December 21, 2020, 11:28pm

Rendering images in terminal.

sudo dnf install chafa # Fedora/CentOS/RHEL
sudo apt install chafa # Debian/Ubuntu

chafa IMAGE_FILE

Terminal font size set at: 2pt

Terminal font size set at: 12pt

Virtual console:

Awoooooooo…

Ulfnic · December 22, 2020, 12:55am

chafa animated GIF example:

chafa https://media.giphy.com/media/f63ra8KYIvWGA/giphy.gif

Similar to the next one, this is a GIF of a GIF so expect smoother results.

Cooked up some chafa sprite animation instructions:

# Sprites source: https://www.gameart2d.com/free-dino-sprites.html

wget https://www.gameart2d.com/uploads/3/0/9/1/30917885/freedinosprite.zip
unzip freedinosprite.zip
cd ./png
nano run.sh
# Paste the following:

#!/bin/bash
i=1
while true; do
	chafa --clear -size 50 "Walk ($((i++))).png"
	if [ $i = 11 ]; then i=1; fi
	sleep 0.05
done

# Save
chmod +x ./run.sh
./run.sh
# Hold down Ctrl+C to stop

Peek 2020-12-22 00-35

Ulfnic · December 27, 2020, 5:20am

Tip of the week: Notice my bad practice above --^

Train yourself to use chmod u+x instead of chmod +x

chmod +x grants executable rights system wide, chmod u+x just grants rights to the file’s owner which is usually all you want.

Try it yourself:

# Create files named A, B and C in the current directory
touch ./A ./B ./C

# Observe the initial file rights
ls -la ./A ./B ./C

# Give everyone executable access to A (same as chmod a+x)
chmod +x ./A

# Give just the owner executable access to B
chmod u+x ./B

# Give just the owner and group executable access to C
chmod ug+x ./C

# Observe the new rights
ls -la ./A ./B ./C

# Cleanup
rm ./A ./B ./C

Security Bonus:

Don’t give executable rights to files at all and just run them directly. Examples:
bash ./MY_FILE
sh ./MY_FILE

rwaltr · December 27, 2020, 6:24am

Add these to your bashrc and thank me later

#Shell Options
shopt -s autocd # change to named directory
shopt -s cdspell # autocorrects cd misspellings
shopt -s cmdhist # save multi-line commands in history as single line
shopt -s dotglob
shopt -s histappend # do not overwrite history
shopt -s expand_aliases # expand aliases
shopt -s checkwinsize # checks term size when bash regains control
bind "set completion-ignore-case on"

# Custom Alias

# easy resource
alias resource="source ~/.bashrc"


# Easy Open
alias open="xdg-open"

# IP colors
alias ip='ip -br -c'

alias tb='nc termbin.com 9999'
alias termbin=tb

Ulfnic · December 27, 2020, 8:02am

ip has colors and a tabular mode… whhhhattttttt

Ulfnic · December 29, 2020, 10:46am

.bashrc lsusers()

Credit to terminalforlife, arguably THE most underrated terminal focused show on YouTube.

Lots of .bashrc goodies here:

https://github.com/terminalforlife/BashConfig/blob/master/source/.bash_functions

Highlighting a really nice one, this’ll list all the users on the system (from /etc/passwd) in a human readable table.

nano ~/.bashrc
# Paste the following somewhere within:

# lsusers() Repo: https://github.com/terminalforlife/BashConfig/blob/master/source/.bash_functions
# lsusers() License: https://github.com/terminalforlife/BashConfig/blob/master/LICENSE
lsusers(){ #: List users on the system, according to '/etc/passwd'.
	printf "%-20s %-7s %-7s %-25s %s\n" "USERNAME" "UID" "GID" "HOME" "SHELL"

	local X
	while IFS=':' read -a X; do
		if [ "$1" == "--nosys" ]; then
			# It's possible some users might show up if they mistakenly
			# were given a HOME, but '--nosys' should otherwise work.
			if [[ ${X[5]/\/home\/syslog} == /home/* ]]; then
				printf "%-20s %-7d %-7d %-25s %s\n"\
					"${X[0]}" "${X[2]}" "${X[3]}"\
					"${X[5]}" "${X[6]}"
			fi
		else
			printf "%-20s %-7d %-7d %-25s %s\n" "${X[0]}"\
				"${X[2]}" "${X[3]}" "${X[5]}" "${X[6]}"
		fi
	done < /etc/passwd
}

Compare:

Ulfnic · January 4, 2021, 11:36am

Exitting VIM

A 2017 study including over 1,000,000 developers found jQuery devs were the most likely to get stuck in VIM:

Know your way out!

Pressing Escape won’t allow you to “escape” VIM but it will get you back to Normal mode.
From Normal mode you can enter Command mode by pressing :
Now you can enter a command to exit VIM, then press enter (to exit).

Examples:

:q #Quit
:q! #Rage quit (quit and discard changes)
:wq #Save and quit
:x #Also Save and quit
:qa #Quit all open files
:qa! #Rage quit all open files

Exit directly from Normal mode:

Esc + Shift ZZ #Save and quit
Esc + Shift ZQ #Rage quit

Remote recovery: (if all else fails)

SSH into the machine and run: pkill vim

grumpey · January 4, 2021, 11:51am

:w !sudo tee %

I always need to save when I forget to sudo.