This is just a quick-and-dirty one-liner. I was compiling beamer slides, and for some reason the TikZ-generated PDF figures contained two pages under some circumstances. This way we can quickly see whether just some PDF files or all of them suffered a problem:

$ find figure/ -type f -name "*.pdf" -exec pdftk "{}" dump_data \; | grep NumberOfPages | awk '{print $2}'
1
1
1
1
1
1

(in this case they were all one page long).

• https://stackoverflow.com/questions/14704274/how-to-write-shell-script-for-finding-number-of-pages-in-pdf

This is just awesome! An open source magnetic stir heating plate!