git pre-commit hook to prevent committing files that contain a certain string

pre-commit

#!/bin/sh

git diff-index --name-status --cached HEAD -- | cut -c3- | while read FILE
do
  if git diff --cached "$FILE" | grep -q "^+[^+].*// NOCOMMIT"; then
    echo $FILE ' contains a NOCOMMIT string!'
    exit 1
  fi
done