Strip PDF Metadata

The article describes a shell script (`clean_pdf.sh`) that recursively finds PDF files in a specified directory (or the current directory) and strips their top-level metadata using `exiftool` and `qpdf`. The script creates a temporary clean copy of each PDF, linearizes it, and replaces the original file, though it notes that only file-level metadata is removed, not metadata within embedded images. The code is provided as-is with no guarantees of safety or effectiveness.

clean pdf.sh This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters Show hidden characters -------------------------------------------------------------------- Recursively find pdfs from the directory given as the first argument, otherwise search the current directory. Use exiftool and qpdf both must be installed and locatable on $PATH to strip all top-level metadata from PDFs. Note - This only removes file-level metadata, not any metadata in embedded images, etc. Code is provided as-is, I take no responsibility for its use, and I make no guarantee that this code works or makes your PDFs "safe," whatever that means to you. You may need to enable execution of this script before using, eg. chmod +x clean pdf.sh example: clean current directory: ./clean pdf.sh clean specific directory: ./clean pdf.sh some/other/directory -------------------------------------------------------------------- Color Codes so that warnings/errors stick out GREEN="\e 32m" RED="\e 31m" CLEAR="\e 0m" loop through all PDFs in first argument $1 , or use '.' this directory if not given DIR="${1:-.}" echo "Cleaning PDFs in directory $DIR" use find to locate files, pip to while read to get the whole line instead of space delimited Note -- this will find pdfs recursively find $DIR -type f -name " .pdf" | while read -r i do output file as original filename with suffix clean.pdf TMP=${i%. } clean.pdf remove the temporary file if it already exists if -f "$TMP" ; then rm "$TMP"; fi exiftool -q -q -all:all= "$i" -o "$TMP" qpdf --linearize --deterministic-id --replace-input "$TMP" echo -e $ printf "${GREEN}Processed ${RED}${i} ${CLEAR}as ${GREEN}${TMP}${CLEAR}" done