# bulk / batch PDF manipulation
# rename based on metdata
pdf-title-rename *.pdf -d /path/to/files -n -i

# remove unsafe chars
detox -n -r -v /path/to/files

# minor tidy up
rename -n "s/-/ /g" *
rename "s/-/ /g" *
rename "s/  / /g" *
rename "s/?/ /g" *
rename "s/\?/ /g" *

# then the icing...
find -type f -name "*.pdf" -exec bash -c 'gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dBATCH -dQUIET -sOutputFile="new.pdf" "{}"; rm "{}"; mv "new.pdf" "{}";' {} \;