alacritty_opacity_changer

#!/bin/bash

# path of your alacritty config file
# this should be the default path
FILE_LOC="/home/$USER/.config/alacritty/alacritty.yml"

def_change_opacity ()
{
	delta_val="0.05"
	METRIC_ID="background_opacity"

	if [[ $1 -eq 1 ]]; then
		delta_val=$(echo "$delta_val*1" | bc)
	elif [[ $1 -eq -1 ]]; then
		delta_val=$(echo "$delta_val*-1" | bc)
	else
		echo "usage: <cmd> <+1/-1>"
		echo "    +1 : increase opacity"
		echo "    -1 : decrease opacity"
		exit
	fi

	# finding current opacity value and stripping of white space
	opacity_val=$(grep $METRIC_ID $FILE_LOC | cut -d':' -f2 | cut -d' ' -f2)

	# if opacity values are beyond the range of 0/1
	# then exit the program

	val1=$(echo "$opacity_val==0 && $1==-1" | bc)
	val2=$(echo "$opacity_val==1 && $1==1" | bc)

	# lower extreme (min opacity)
	if [[ $val1 -eq 1 ]]; then
		exit
	# upper extreme (max opacity)
	elif [[ $val2 -eq 1 ]]; then
		exit
	fi

	# calculating new opacity value by applying delta change 
	new_opacity_val=$(echo "$opacity_val+$delta_val" | bc)

	# replacing old value with new value
	sed -i "s/$METRIC_ID: $opacity_val/$METRIC_ID: $new_opacity_val/g" $FILE_LOC
}

def_change_opacity $1