How to count number of pages in a PDF?

Rails
1

Does any know a simple way to count the number of pages in a PDF file?
I’m
using teh RTEX plugin to generate a PDF via pdflatex with a defined
start page
number. I want to determine the final page number so I can start the
next PDF
in sequence.

Thanks in advance for your help!

-cal

2

I am using pdfbox for that, open source and simple to use if you are
familiar with java, but comes with the cost of starting a JVM. There is
also
a comercial lib called PDFLib, which now has Ruby bindings and which
works
very well in general.

Maybe there is an even simpler way, I also would like to know.