BTC Halving monitor - A simple bash script to tell how many blocks rest for the next halving

halving_monitor

#!/usr/bin/env bash

declare -A COLOR
COLOR['END']='\033[0m'
COLOR['RED']='\033[0;31m'
COLOR['GREEN']='\033[0;32m'
COLOR['YELLOW']='\033[0;33m'
COLOR['BLUE']='\033[0;34m'
COLOR['WHITE']='\033[0;37m'

function json_extract() {
 local key=$1
 local json=$2

 local string_regex='"([^"\]|\\.)*"'
 local number_regex='-?(0|[1-9][0-9]*)(\.[0-9]+)?([eE][+-]?[0-9]+)?'
 local value_regex="${string_regex}|${number_regex}|true|false|null"
 local pair_regex="\"${key}\"[[:space:]]*:[[:space:]]*(${value_regex})"

 if [[ ${json} =~ ${pair_regex} ]]; then
    echo $(sed 's/^"\|"$//g' <<< "${BASH_REMATCH[1]}")
 else
    return 1
 fi
}

readonly period=210000

api="https://mempool.space/api/v1/mining/blocks/timestamp/"
timestamp=$(date +%s)
remain=0
next_halving=0
while true 
do
	clear
	body=$(curl -sSL $api$timestamp)
	timestamp=$(date +%s)
	curret_block=$(json_extract "height" "$body")
	
	if (( $(($curret_block%$period)) == 0 )); then
		echo -e "${COLOR['GREEN']}IT's HALVING BLOCK BABY!!! ${COLOR['END']}"
		remain=0
	else 
		next_halving=$(( ($curret_block/$period)*$period + $period ))
		remain=$(($next_halving-$curret_block))
	fi

	echo -ne "\033[H\033[J"
	echo -e "The timestamp is $timestamp"
	echo -e "${COLOR['YELLOW']}[INFO] The current block is ${COLOR['GREEN']}$curret_block ${COLOR['END']}"	
	echo -e "${COLOR['GREEN']}Halving on block $next_halving ${COLOR['END']}"
	echo -e "${COLOR['BLUE']}Rest ${COLOR['RED']}$remain ${COLOR['BLUE']}blocks to Halving${COLOR['END']}"
	sleep 5
done