#!/bin/sh while getopts f:t: opt; do case $opt in f) from="$OPTARG";; t) to="$(echo "$OPTARG" | tr '[:lower:]' '[:upper:]')";; \?) exit 1;; esac done # https://docs.cloud.coinbase.com/sign-in-with-coinbase/docs/api-exchange-rates curl -s "https://api.coinbase.com/v2/exchange-rates?currency=${from:-xmr}" | jq -r ".data.rates.${to:-USD}"