seedqr_standard.sh

#!/bin/bash

readonly bip39_list="bip-39-eng-wordlist.txt"

check_wordlist() {
  if [ ! -f "${bip39_list}" ]; then
    curl -s \
    https://raw.githubusercontent.com/bitcoin/bips/master/bip-0039/english.txt \
    > "${bip39_list}"
  fi
}

# ./seedqr_standard decode "000000010002000300040005000600070008000900100011"
decode() {
  check_wordlist
  echo "$@" > .encoded
  while IFS= read -r -n4 char
  do
    if [ -n "${char}" ]; then
      num=$(echo $char | sed 's/^0*//')
      index=$((num+1))
      sed -n "${index}p" "${bip39_list}"
    fi
  done < ".encoded"
}

# ./seedqr_standard encode "abandon ability able about above absent absorb abstract absurd abuse access accident"
encode() {
  check_wordlist
  local words="$1"

  for word in $words; do
    index=$(grep -no -E "^$word\$" $bip39_list | cut -d':' -f1)
    [ -z "${index}" ] && echo "$word not on list" && exit 1
    index=$((index-1))
    printf "%04g" $index
  done
}

# Check if the function exists (bash specific)
if declare -f "$1" > /dev/null
then
  # call arguments verbatim
  "$@"
else
  # Show a helpful error
  echo "'$1' is not a known function name" >&2
  exit 1
fi