Git pre-commit hook to prevent non-ascii characters

pre-commit.bash

#!/bin/bash
 
# Save these contents to .git/hooks/pre-commit in your project 
# folder, and give it executable permissions with
# "chmod u+x .git/hooks/pre-commit"
# Git will abort a commit if you have non ASCII characters in 
# the commit, and output the non ASCII characters.
output=`git diff HEAD | tr -d "\000-\011\013-\177" | tr -d '\n'`
cnt=${#output}
if [ -n "$output" ]; then
  echo "Aborting commit! Non ascii characters found in change set:"
  for ((i=0; i < cnt; i++))
  do
    char=${output:$i:1}
    echo ""
    echo "Found character '$char':"
    git diff HEAD -S$char
  done
  exit 1
fi
exit 0

It's a nice directioh, But this approach will work only when adding new non ascii char. However, it will not work when you delete an old non-ascii and the commit will fail..