bitcoin exchange rates

bitcoin/btc_rates.sh

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+#!/usr/bin/env bash
+
+#
+# btc_rates.sh
+#
+# Command line interface for BitBay Bitcoin exchange rates.
+#
+# Author: Nils Knieling - https://github.com/Cyclenerd
+#
+
+PROG=$(basename "$0")
+
+#####################################################################
+# Usage
+#####################################################################
+
+function usage {
+	returnCode="$1"
+	echo
+	echo -e "Usage: $PROG [-b <BTC>] [-d <USD>] [-e <EUR>] [-h]:
+	[-b <BTC>]\t Bitcoins to Eurozone Euro and US Dollar
+	[-d <USD>]\t US Dollar to Bitcoins
+	[-e <EUR>]\t Eurozone Euro to Bitcoins
+	[-h]\t\t displays help (this message)"
+	echo
+	exit "$returnCode"
+}
+
+
+#####################################################################
+# Terminal output helpers
+#####################################################################
+
+# exit_with_failure() outputs a message before exiting the script.
+function exit_with_failure() {
+	echo
+	echo "ERROR: $1"
+	echo
+	exit 9
+}
+
+
+#####################################################################
+# Other helpers
+#####################################################################
+
+# command_exists() tells if a given command exists.
+function command_exists() {
+	command -v "$1" >/dev/null 2>&1
+}
+
+
+#####################################################################
+# Let's start
+#####################################################################
+
+if ! command_exists curl; then
+	exit_with_failure "'curl' is needed. Please install 'curl'. More details can be found at https://curl.haxx.se/"
+fi
+
+while getopts ":b:d:e:h" opt; do
+	case $opt in
+	b)
+		MY_BTC="$OPTARG"
+		;;
+	d)
+		MY_USD="$OPTARG"
+		;;
+	e)
+		MY_EUR="$OPTARG"
+		;;
+	h)
+		usage 0
+		;;
+	*)
+		echo "Invalid option: -$OPTARG"
+		usage 1
+		;;
+	esac
+done
+
+MY_BTC_EUR=$(curl -k -s -f "https://bitpay.com/api/rates/eur" | tr -d '{"code":"EUR","name":"Eurozone Euro","rate":' | tr -d '}')
+MY_BTC_USD=$(curl -k -s -f "https://bitpay.com/api/rates/usd" | tr -d '{"code":"USD","name":"US Dollar","rate":' | tr -d '}')
+
+echo
+echo "---------------------------------------------"
+echo "Bitcoin Exchange Rates"
+echo "    https://bitpay.com/bitcoin-exchange-rates"
+echo "---------------------------------------------"
+
+# 1 BTC to EUR
+if [[ $MY_BTC_EUR =~ ^[0-9\.]+$ ]]; then
+	printf "%.0f BTC  ⤮   € %.6f EUR\n" "1" $MY_BTC_EUR
+else
+	exit_with_failure "Can not find Eurozone Euro (€) exchange rate!"
+fi
+
+# 1 BTC to USD
+if [[ $MY_BTC_USD =~ ^[0-9\.]+$ ]]; then
+	printf "%.0f BTC  ⤮   $ %.6f USD\n" "1" $MY_BTC_USD
+else
+	exit_with_failure "Can not find US Dollar ($) exchange rate!"
+fi
+
+# n BTC to EUR and USD
+if [[ $MY_BTC =~ ^[0-9\.]+$ ]]; then
+	MY_BTC_TO_EUR=$(echo "$MY_BTC * $MY_BTC_EUR" | bc -l)
+	MY_BTC_TO_USD=$(echo "$MY_BTC * $MY_BTC_USD" | bc -l)
+	echo "---------------------------------------------"
+	printf "%.6f BTC  ⤮   € %.6f EUR\n" $MY_BTC $MY_BTC_TO_EUR
+	printf "%.6f BTC  ⤮   € %.6f USD\n" $MY_BTC $MY_BTC_TO_USD
+fi
+
+# n EUR to BTC
+if [[ $MY_EUR =~ ^[0-9\.]+$ ]]; then
+	MY_EUR_TO_BTC=$(echo "1 / $MY_BTC_EUR * $MY_EUR" | bc -l)
+	MY_EUR_TO_MBTC=$(echo "$MY_EUR_TO_BTC * 1000" | bc -l)
+	echo "---------------------------------------------"
+	printf "%.6f EUR  ⤮   ฿ %.6f BTC\n"  $MY_EUR $MY_EUR_TO_BTC
+	printf "%.6f EUR  ⤮   ฿ %.6f mBTC\n" $MY_EUR $MY_EUR_TO_MBTC
+fi
+
+# n USD to BTC
+if [[ $MY_USD =~ ^[0-9\.]+$ ]]; then
+	MY_USD_TO_BTC=$(echo "1 / $MY_BTC_USD * $MY_USD" | bc -l)
+	MY_USD_TO_MBTC=$(echo "$MY_USD_TO_BTC * 1000" | bc -l)
+	echo "---------------------------------------------"
+	printf "%.6f USD  ⤮   ฿ %.6f BTC\n"  $MY_USD $MY_USD_TO_BTC
+	printf "%.6f USD  ⤮   ฿ %.6f mBTC\n" $MY_USD $MY_USD_TO_MBTC
+fi
+
+echo