Shows Bitcoin transactions and updates when a new block is added to the blockchain.

main.go

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"strconv"
	"time"
)

type Block struct {
	Hash       string `json:"hash"`
	Time       int    `json:"time"`
	BlockIndex int    `json:"block_index"`
	Height     int    `json:"height"`
	TxIndexes  []int  `json:"txIndexes"`
}

type RawTransaction struct {
	Out []Transaction `json:"out"`
}

type Transaction struct {
	Addr  string `json:"addr"`
	Value int    `json:"value"`
}

type BTCPrice struct {
	Last string `json:"last"`
}

var lasthash string
var currentex float64
var bltrans int

func reqFromUrl(url string) []byte {
	res, err := http.Get(url)
	if err != nil {
		panic(err)
	}
	b, err := ioutil.ReadAll(res.Body)
	defer res.Body.Close()
	if err != nil {
		panic(err)
	}

	return b
}

func main() {
	go func() {
		for {

			btcp := new(BTCPrice)
			err := json.Unmarshal(reqFromUrl("https://www.bitstamp.net/api/ticker/"), btcp)
			if err != nil {
				panic(err)
			}
			currentex, err = strconv.ParseFloat(btcp.Last, 64)
			if err != nil {
				panic(err)
			}
			time.Sleep(time.Second * 60)
		}
	}()

	time.Sleep(time.Second * 3)

	for {
		bl := new(Block)
		err := json.Unmarshal(reqFromUrl("https://blockchain.info/latestblock"), bl)
		if err != nil {
			panic(err)
		}

		if bl.Hash == lasthash {
			time.Sleep(time.Minute)
			continue
		} else {
			lasthash = bl.Hash
		}

		for _, x := range bl.TxIndexes {
			tr := new(RawTransaction)
			err = json.Unmarshal(reqFromUrl(fmt.Sprintf("https://blockchain.info/rawtx/%d", x)), tr)
			if err != nil {
				panic(err)
			}
			for _, a := range tr.Out {
				if a.Addr == "" {
					continue
				}
				btc := float64(a.Value) / float64(100000000)
				fmt.Printf("\033[1;37m①\033[0;32m #%-4d  \033[1;37m②\033[0;32m %-7d  \033[1;37m③\033[0;32m %-34s  \033[1;37m④\033[0;32m ฿%-12f  \033[1;37m⑤\033[0;32m $%-12.2f\n",
					bltrans, bl.Height, a.Addr, btc, currentex*btc)
				bltrans++
			}
		}
		bltrans = 0
	}
}