How to count number of pages in a PDF?


Does any know a simple way to count the number of pages in a PDF file?
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!



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
a comercial lib called PDFLib, which now has Ruby bindings and which
very well in general.

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