Asciify a spell-check dictionary (word list). It filters words from a .dic with non-ascii chars and transforms the words into ascii-only versions. https://github.com/streetsidesoftware/cspell/issues/1060#issuecomment-1006199819

asciify-dic.sh

#!/usr/bin/env bash
#License: "Zero-Clause BSD" <https://opensource.org/licenses/0BSD>
# Requires perl and unidecode module (in Ubuntu, it can be installed with sudo apt install libtext-unidecode-perl).
# Example usage: asciify-dic $DIC_NAME.dic > $DIC_NAME-asciified.dic

if [[ "$1" == "--help" ]]; then
  echo "Usage: $(basename "$0") INPUT_FILE > OUTPUT_FILE"
  echo "Asciify a .dic file (list of dictionary words)."
  echo ""
  echo "Generates a file with ASCII-only versions of the words that have non-ASCII chars."
  echo "These additional words can be used to make spell-checking accent-insensitive."
  echo "Comment lines beginning with % are left unchanged."
  exit
fi
# Filter words containing non-ascii characters, except in comments
grep -P '^\%|[^\x00-\x7F]' $1 |
# Make words accent-insensitive, except in comments
perl -C -MText::Unidecode -pe'next if /^\s*%/;unidecode($_)' |
# Remove duplicate lines, except in comments
awk '/^\s*%/||!seen[$0]++'