shell script used as "CGI handler" to use .url files as "hotlinks"

.htaccess

#this does NOT have to be in webroot!
AddType text/x-url url
Action text/x-url /cgi-bin/webroot/relative/path/to/URL.cgi

example.url

[InternetShortcut]
URL=https://gist.github.com/b845f0f9f06cb0db42918107e9eda18c

hiawatha-url.conf.include

# include this from your main hiawatha.conf, or just put its contents in
CGIHandler = /absolute/path/to/URL.cgi:url
# Don't forget to add "CGIHandler = /absolute/path/to/URL.cgi" to cgi-wrapper.conf if you're using CGIWrapper

URL.cgi

#!/bin/sh

while read -r line; do
  case "${line}" in
   "URL="*|"http"*)
      url="${line#"URL="}"
      break
      ;;
  esac
done < "${PATH_TRANSLATED="${1}"}"

if [ ! -z "${url}" ]; then
  status="302 Found"
  content_type="text/x-url"
elif [ -r "${PATH_TRANSLATED}" ]; then
  status="200 OK"
  content_type="application/x-url"
elif [ -e "${PATH_TRANSLATED}" ]; then
  status="403 Access Denied"
fi

exec printf "Status: %s\r\n${content_type+"Content-Type: %s\\r\\n"}${url+"Location: %s\\r\\n"}\r\n"\
 "${status?"500 Internal Server Error"}"\
 ${content_type+"${content_type}"}\
 ${url:+"${url}"}

exec cat "${PATH_TRANSLATED}"