Convert terrible 8.3-formatted font filenames to their internal fullname using the Fontconfig library tools.

convert_font_filenames

#!/usr/bin/env bash

needs() {
  local bin="$1";
  shift;
  command -v "$bin" > /dev/null 2>&1 || {
    printf "%s is required but it's not installed or in PATH; %s\n" "$bin" "$*" 1>&2;
    return 1
  }
}

needs fc-scan install fontconfig || exit 1

for file in *.{ttf,TTF,otf,OTF,ttc,TTC,pfm,PFM,pfb,PFB}; do
  # Extract fullname and take the first item if comma-separated
  fontname=$(fc-scan --format "%{fullname}\n" "$file" | awk -F ',' '{print $1}' | tr -dc '[:alnum:][:space:]()_\-.\[\]')
  
  # If the fullname is empty, skip renaming
  if [ -z "$fontname" ]; then
    echo "Could not extract a name for file: $file. Skipping..." >&2
    continue
  fi

  # Get file extension and rename the file
  ext="${file##*.}"
  # downcase it. requires bash 4+
  ext="${ext,,}"
  newname="$fontname.$ext"

  # If the new name is the same as the old name, continue
  if [ "$file" = "$newname" ]; then
    echo "File $file already has the correct name. Skipping..." >&2
    continue
  fi

  # If a file with the new name already exists and they are the same, delete the old file
  if [ -e "$newname" ] && cmp --silent "$file" "$newname"; then
    rm "$file"
    echo "Removed duplicate file: $file"
  else
    mv "$file" "$newname"
  fi
done