104 lines
2.1 KiB
Bash
104 lines
2.1 KiB
Bash
#!/bin/sh
|
|
# xchg-rates
|
|
# Written in 2023 by Lucas
|
|
# CC0 1.0 Universal/Public domain - No rights reserved
|
|
#
|
|
# To the extent possible under law, the author(s) have dedicated all
|
|
# copyright and related and neighboring rights to this software to the
|
|
# public domain worldwide. This software is distributed without any
|
|
# warranty. You should have received a copy of the CC0 Public Domain
|
|
# Dedication along with this software. If not, see
|
|
# <http://creativecommons.org/publicdomain/zero/1.0/>.
|
|
|
|
usage()
|
|
{
|
|
cat - <<EOF >&2
|
|
Usage:
|
|
${0##*/} amount from to
|
|
${0##*/} -l
|
|
|
|
Rates By Exchange Rate API - https://www.exchangerate-api.com
|
|
EOF
|
|
exit 1
|
|
}
|
|
|
|
err()
|
|
{
|
|
printf "%s: %s\n" "${0##*/}" "$*" >&2
|
|
exit 1
|
|
}
|
|
|
|
warn()
|
|
{
|
|
printf "%s: %s\n" "${0##*/}" "$*" >&2
|
|
}
|
|
|
|
date_gt()
|
|
{
|
|
expr "X$1" ">" "X$2" >/dev/null
|
|
}
|
|
|
|
RATES_API=https://open.er-api.com/v6/latest/USD
|
|
fetch_rates()
|
|
{
|
|
ftp -o "$RATES_JSON" "$RATES_API"
|
|
}
|
|
|
|
cachedir=${XDG_CACHE_HOME:-~/.cache}/xchg-rates
|
|
mkdir -p "$cachedir"
|
|
|
|
: ${RATES_JSON:=$cachedir/rates.json}
|
|
|
|
do_list=false
|
|
while getopts l flag; do
|
|
case $flag in
|
|
l) do_list=true ;;
|
|
*) usage ;;
|
|
esac
|
|
done
|
|
shift $(($OPTIND - 1))
|
|
|
|
if [ ! -f "$RATES_JSON" ]; then
|
|
fetch_rates
|
|
fi
|
|
|
|
next_update_unix=$(jq -er .time_next_update_unix "$RATES_JSON")
|
|
if [ $? -ne 0 ]; then
|
|
fetch_rates
|
|
else
|
|
next_update=$(date -r "$next_update_unix" +%Y%m%dT%H%M%SZ)
|
|
now=$(date +%Y%m%dT%H%M%SZ)
|
|
if date_gt "$now" "$next_update"; then
|
|
fetch_rates
|
|
fi
|
|
fi
|
|
|
|
eol=$(jq -r '.time_eol_unix' "$RATES_JSON")
|
|
if [ X"$eol" != X"0" ]; then
|
|
warn "EOL set for $(date -j "$eol" +%Y%m%dT%H%M%SZ)"
|
|
fi
|
|
|
|
if $do_list; then
|
|
jq -r '.rates | to_entries | .[].key' "$RATES_JSON" | sort
|
|
exit $?
|
|
fi
|
|
|
|
if [ $# -ne 3 ]; then
|
|
usage
|
|
fi
|
|
amount=$1
|
|
from=$(echo "$2" | tr a-z A-Z)
|
|
to=$(echo "$3" | tr a-z A-Z)
|
|
|
|
if ! jq --arg k "$from" -er '.rates | has($k)' "$RATES_JSON" >/dev/null; then
|
|
err "no rate for $from"
|
|
fi
|
|
if ! jq --arg k "$to" -er '.rates | has($k)' "$RATES_JSON" >/dev/null; then
|
|
err "no rate for $to"
|
|
fi
|
|
jq -r --arg from "$from" --arg to "$to" \
|
|
'.rates | [.[$from], .[$to]] | @tsv' "$RATES_JSON" | {
|
|
read -r from to
|
|
echo "$amount / $from * $to" | bc -l
|
|
}
|