ledger price database "getquote" tool for cryptocurrencies using coinmarketcap

getquote-coinmarketcap.sh

#!/bin/bash

# by colindean
# unlicensed, public domain: https://unlicense.org

# invocation:
#   getquote-coinmarketcap.sh crypto-transactions.ledger
#
# This tool may try to look up any commodity that is in the commodity list.
# I recommend tracking cryptocurrencies in a separate ledger file that is
# included from the main file used in querying.

LEDGER_FILE="$1"

if [[ -z "${LEDGER_FILE}" ]]; then
  >&2 echo "Specify a ledger file as the first argument"
  exit 1
fi

LEDGER="$(command -v ledger)"
if [[ -z "${LEDGER}" ]]; then
  >&2 echo "Ledger not found in PATH. Is it installed?"
  exit 2
fi

CURL="$(command -v curl)"
if [[ -z "${CURL}" ]]; then
  >&2 echo "curl not found in PATH. Is it installed?"
  exit 3
fi

JQ="$(command -v jq)"
if [[ -z "${JQ}" ]]; then
  >&2 echo "jq not found in PATH. Is it installed?"
  exit 4
fi

JSON="$("${CURL}" -q 'https://api.coinmarketcap.com/v1/ticker/?limit=0')"

for symbol in `"${LEDGER}" -f "${LEDGER_FILE}" commodities`; do
  case ${symbol} in
    # cryptos not tracked on coinmarketcap plus some common fiat currencies that might be commingled.
    "NSC" | "cyberShare" | "USD" | "EUR" | "CAD" )
      continue
      ;;
    # ambiguous symbols need special handling
    "BTG" )
      price="$(echo "$JSON" | "${JQ}" -r ".[] | select(.id == \"bitcoin-gold\") | .price_usd")"
      last_updated_secs="$(echo "$JSON" | "${JQ}" -r ".[] | select(.id == \"bitcoin-gold\") | .last_updated")"
      ;;
    *)
      price="$(echo "$JSON" | "${JQ}" -r ".[] | select(.symbol == \"${symbol}\") | .price_usd")"
      last_updated_secs="$(echo "$JSON" | "${JQ}" -r ".[] | select(.symbol == \"${symbol}\") | .last_updated")"
      ;;
  esac
  #TODO: this is dependent on BSD date, not GNU date, which wants `date -d @secs format`
  ts="$(date -r ${last_updated_secs} "+%Y-%m-%d %H:%I:%S")"
  echo "P ${ts} ${symbol} ${price} USD"
done

# TODO: can jq handle the output formatting?