Title: Simple scripts I made over time

	Title: Simple scripts I made over time
	Author: Solène
	Date: 19 July 2021
	Tags: openbsd scripts shell
	Description:

	# Introduction

	I wanted to share a few scripts of mine for some time, here they are!

	# Scripts

	Over time I'm writing a few scripts to help me in some tasks, they are
	often associated to a key binding or at least in my ~/bin/ directory
	that I add to my $PATH.

	## Screenshot of a region and upload

	When I want to share something displayed on my screen, I use my simple
	"screen_up.sh" script (super+r) that will do the following:

	* use scrot and let me select an area on the screen
	* convert the file in jpg but also png compression using pngquant and
	pick the smallest file
	* upload the file to my remote server in a directory where files older
	than 3 days are cleaned (using find -ctime -type f -delete)
	* put the link in the clipboard and show a notification

	This simple script has been improved a lot over time like getting a
	feedback of the result or picking the smallest file from various
	combinations.

	```script shell requiring scrot, pngquant, ImageMagick and notify-send
	#!/bin/sh
	test -f /tmp/capture.png && rm /tmp/capture.png
	scrot -s /tmp/capture.png
	pngquant -f /tmp/capture.png
	convert /tmp/capture-fs8.png /tmp/capture.jpg
	FILE=$(ls -1Sr /tmp/capture* \| head -n 1)
	EXTENSION=${FILE##*.}

	MD5=$(md5 -b "$FILE" \| awk '{ print $4 }' \| tr -d '/+=' )

	ls -l $MD5

	scp $FILE perso.pw:/var/www/htdocs/solene/i/${MD5}.${EXTENSION}
	URL="https://perso.pw/i/${MD5}.${EXTENSION}"
	echo "$URL" \| xclip -selection clipboard

	notify-send -u low $URL
	```

	## Uploading a file temporarily

	Second most used script of mine is a uploading file utility. It will
	rename a file using the content md5 hash but keeping the extension and
	will upload it in a directory on my server where it will be deleted
	after a few days from a crontab. Once the transfer is finished, I get
	a notification and the url in my clipboard.

	```script shell
	#!/bin/sh
	FILE="$1"

	if [ -z "$1" ]
	then
	echo "usage: [file]"
	exit 1
	fi


	MD5=$(md5 -b "$1" \| awk '{ print $NF }' \| tr -d '/+=' )
	NAME=${MD5}.${FILE##*.}

	scp "$FILE" perso.pw:/var/www/htdocs/solene/f/${NAME}

	URL="https://perso.pw/f/${NAME}"
	echo -n "$URL" \| xclip -selection clipboard

	notify-send -u low "$URL"
	```

	## Sharing some text or code snippets

	While I can easily transfer files, sometimes I need to share a snippet
	of code or a whole file but I want to ease the reader work and display
	the content in an html page instead of sharing an extension file that
	will be downloaded. I don't put those files in a cleaned directory and
	I require a name to give some clues about the content to potential
	readers. The remote directory contains a highlight.js library used to
	use syntactic coloration, hence I pass the text language to use the
	coloration.

	```
	#!/bin/sh

	if [ "$#" -eq 0 ]
	then
	echo "usage: language [name] [path]"
	exit 1
	fi

	cat > /tmp/paste_upload <<EOF
	<html>
	<head>
	<meta http-equiv="Content-type" content="text/html; charset=utf-8" />
	</head>
	<body>
	<link rel="stylesheet" href="default.min.css">
	<script src="highlight.min.js"></script>
	<script>hljs.initHighlightingOnLoad();</script>

	<pre><code class="$1">
	EOF

	# ugly but it works
	cat /tmp/paste_upload \| tr -d '\n' > /tmp/paste_upload_tmp
	mv /tmp/paste_upload_tmp /tmp/paste_upload

	if [ -f "$3" ]
	then
	cat "$3" \| sed 's/</\</g' \| sed 's/>/\>/g' >> /tmp/paste_upload
	else
	xclip -o \| sed 's/</\</g' \| sed 's/>/\>/g' >> /tmp/paste_upload
	fi


	cat >> /tmp/paste_upload <<EOF


	</code></pre> </body> </html>
	EOF


	if [ -n "$2" ]
	then
	NAME="$2"
	else
	NAME=temp
	fi

	FILE=$(date +%s)_${1}_${NAME}.html

	scp /tmp/paste_upload perso.pw:/var/www/htdocs/solene/prog/${FILE}

	echo -n "https://perso.pw/prog/${FILE}" \| xclip -selection clipboard
	notify-send -u low "https://perso.pw/prog/${FILE}"
	```

	## Resize a picture

	I never remember how to resize a picture so I made a one line script to
	not have to remember about it, I could have used a shell function for
	this kind of job.

	```shell code
	#!/bin/sh

	if [ -z "$2" ]
	then
	PERCENT="40%"
	else
	PERCENT="$2"
	fi

	convert -resize "$PERCENT" "$1" "tn_${1}"
	```

	# Latency meter using DNS

	Because UDP requests are not reliable they make a good choice for
	testing network access reliability and performance. I used this as
	part of my stumpwm window manager bar to get the history of my internet
	access quality while in a high speed train.

	The output uses three characters to tell if it's under a threshold (it
	works fine), between two threshold (not good quality) or higher than
	the second one (meaning high latency) or even a network failure.

	The default timeout is 1s, if it works, under 60ms you get a "_",
	between 60ms and 150ms you get a "-" and beyond 150ms you get a "¯",
	if the network is failure you see a "N".

	For example, if your quality is getting worse until it breaks and then
	works, it may look like this: _-¯¯NNNNN-____-_______ My LISP code
	was taking care of accumulating the values and only retaining the n
	values I wanted as history.

	Why would you want to do that? Because I was bored in a train. But
	also, when network is fine, it's time to sync mails or refresh that
	failed web request to get an important documentation page.

	```shell script
	#!/bin/sh

	dig perso.pw @9.9.9.9 +timeout=1 \| tee /tmp/latencecheck

	if [ $? -eq 0 ]
	then
	time=$(awk '/Query time/{
	if($4 < 60) { print "_";}
	if($4 >= 60 && $4 <= 150) { print "-"; }
	if($4 > 150) { print "¯"; }
	}' /tmp/latencecheck)
	echo $time \| tee /tmp/latenceresult
	else
	echo "N" \| tee /tmp/latenceresult
	exit 1
	fi
	```

	# Conclusion

	Those scripts are part of my habits, I'm a bit lost when I don't have
	them because I always feel they are available at hand. While they
	don't bring much benefits, it's quality of life and it's fun to hack on
	small easy pieces of programs to achieve a simple purpose. I'm glad to
	share those.