batch conversion of canon raw files

There were some photos in Canon Raw .CR2 format which were to be uploaded to shutterfly.com which accepts only JPG, JPEG, BMP, PNG, HEIC and HEIF - not CR2 or RAW. So I looked at batch conversions. Most probably it would have been possible to do it in Irfanview, but for Linux, I found this - https://askubuntu.com/questions/483379/how-to-convert-cr2-to-jpg-or-png

In my case, I used

sudo apt install darktable 

for pic in *.CR2
do
     darktable-cli "$pic" "$(basename ${pic%.CR2}.jpg)";
done 

It took nearly 10 seconds per file, but it did the job.