Finds missing pdf files from conversion, then re-fetches them

mhtml-to-pdf2.sh

# Based on my [previous script](https://gist.github.com/J0hnL0cke/95dbf624465034e399592c5d9690eb11) for converting mhtml -> pdf
# This script scans the output directory, in order to figure out if the conversion has failed for any mhtml files

# Instructions
# Install docker
# Set the number on the `tail` commands (in 2 locations now!) to strip file paths (ie "./Readings/filename.mhtml" -> strip first 8 chars -> "filename.mhtml" )
# Run in a directory where you have run `mkdir ./out` and have mhtml files in current folder or subfolders
# To customize where the program searches, for files, edit the path used by the `find` command

IFS=$'\n' &&
 # run a script to get all the missing filenames to iterate over
for filename in $(
  # recursively find all mhtml in the input directory
	for filename in $(find ./ -iname "*.mhtml" -type f )
	do
    # open the file, figure out how the output file should be named.
	  newname=$(grep -m 1 -o "<title>[^<]*" $filename | tail -c+8 | sed 's/[^a-zA-Z0-9 \_\.\-\/\\]//g')
	  newname="$newname.pdf"
	  r=$(find ./out -name "$newname")
	  #echo $r
	  if [ -z "${r}" ]; then
		#echo "file not found! (./out/$newname) "
    # output a list of missing files
		echo "${filename}"
	  #else
		#echo "found file ($newname)"
	  fi
	done

)

do
  # open the file and grep for the content location tag (Snapshot-Content-Location: https://example.com/x)
  tag=$(grep -m 1 "Snapshot-Content-Location: " $filename)
  
  # trim to just the url
	url=$(echo $tag | sed -r 's#.*Snapshot-Content-Location: (.*)#\1#' | sed 's/[^a-zA-Z0-9 \_\.\-\:\/\\]//g')
  
	# name the output file based on the input file's name
  newname=$(grep -m 1 -o "<title>[^<]*" $filename | tail -c+8 | sed 's/[^a-zA-Z0-9 \_\.\-\/\\]//g')
  
	# set the path to save to, append file extension
  newname="./data/out/$newname.pdf"
  
	echo "processing file ($newname) ($url)"
  
	# run wkhtmltopdf on an auto-deleting docker container, and mount the current directory into the container
	sudo docker run --rm --volume "./:/data" --user `id -u`:`id -g` madnight/docker-alpine-wkhtmltopdf $url $newname
	
done && unset IFS