Bash script to titlecase chapter titles in UPPERCASE

2titlecase

for filename in chapter-*.xhtml; do
    new12=$(sed -n '12p' "$filename" | cut -b 8- | se titlecase -n)
    sed -i -e '12s#^\(.*<p>\).*#'"\1$new12"'#g' "$filename"
    ## Uncomment next line to echo new title line to terminal for checking
    # sed -n '12p' "$filename"
  done

This doesn't change case: it takes the filename, truncates the extension, saves that string as variable, and does a search/replace with sed. E.g., for short story file: make the id="..." to id=~~ to make delimiting search easier:

ls | while read filename; do
full="${filename}"
id="${full%.*}"
  sed -i "s/~~/$id/g" ${filename}
done;

(The dquo deliimiters with sed are required for variable replacement in bash.)