How to run PDF to TIFF conversion in parallel? I have this command here for batch converting PDF documents (first 2 pages) to TIFF files using `pdftoppm`. The goal is to put the TIFF images into its own folder with folder name matching the original PDF file name. for file in *.pdf; do pdftoppm -tiff -f 1 -l 2 "$file" ~/tiff/directory/"$file"/"$file" done How can I run 8 instances of the `pdftoppm` command concurrently? I am running Debian. I have 10000s of PDFs to convert to TIFF.

One way would be to create the shell input for all the jobs:


for file in *.pdf
do
printf 'pdftoppm -tiff -f 1 -l 2 "%q" ~/tiff/directory/"%q"/"%q"' \
"$file" "$file" "$file"
done


and then pipe that to `parallel -j N` where N is the number of jobs you want to run simultaneously:


for file in *.pdf
do
printf 'pdftoppm -tiff -f 1 -l 2 "%q" ~/tiff/directory/"%q"/"%q"' \
"$file" "$file" "$file"
done |
parallel -j 8