File: ecbler.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (c) 2026 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the "Software"), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 # ecbler [options...] [amount...]
  27 # European Central Bank Latest Exchange Rates
  28 #
  29 # Emit the latest exchange rates against the euro as 2 lines, the first line
  30 # being a header with the column names. An optional amount multiplies rates,
  31 # if given.
  32 #
  33 # The numbers in the second line are what you multiply each foreign currency
  34 # to get its equivalent amount in euros.
  35 #
  36 # The options are, available both in single and double-dash versions
  37 #
  38 #   -h, -help    show this help message
  39 
  40 
  41 case "$1" in
  42     -h|--h|-help|--help)
  43         awk '/^# +ecbler/, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  44         exit 0
  45     ;;
  46 
  47     --) shift ;;
  48 
  49     -*)
  50         printf "%s: unsupported option '%s'\n" "$0" "$1" >&2
  51         exit 1
  52     ;;
  53 esac
  54 
  55 amt="${1:-1}"
  56 
  57 # load data from the european central bank website
  58 wget -q -O - 'https://www.ecb.europa.eu/stats/eurofxref/eurofxref.zip' |
  59 # decompress payload
  60 gzip -d |
  61 # turn CSV into TSV, ignoring trailing empty fields
  62 sed -E 's- *\r$--; s-,$--; s-, *-\t-g; s-\t+$--' |
  63 # reciprocate dividers into multipliers
  64 awk -F "\t" '
  65     NR == 1 { print }
  66     NR == 2 {
  67         printf "%s", $1
  68         for (i = 2; i <= NF; i++) printf("\t%.6f", 1.0 / $i)
  69         printf "\n"
  70     }
  71 ' |
  72 # pick a subset of the columns
  73 awk -F "\t" -v OFS="\t" '{ print $1, $16, $17, $18, $19, $23, $25, $7, $2 }' |
  74 # turn dates into the yyyy/mm/dd format
  75 sed -E \
  76     -e 's-([0-9]+) ([A-Za-z]{3})[a-z]+ ([0-9]+)-\3/\L\2/\1-g' \
  77     -e 's-jan-01-g' -e 's-feb-02-g' -e 's-mar-03-g' \
  78     -e 's-apr-04-g' -e 's-may-05-g' -e 's-jun-06-g' \
  79     -e 's-jul-07-g' -e 's-aug-08-g' -e 's-sep-09-g' \
  80     -e 's-oct-10-g' -e 's-nov-11-g' -e 's-dec-12-g' |
  81 # multiply by the (optional) amount given
  82 awk -v OFS="\t" -v n="${amt}" 'NR > 1 { for (i = 2; i <= NF; i++) $i *= n } 1'
  83 
  84 # extending the pipe-chain to a step calling `column -t` realigns columns,
  85 # turning tabs into spaces