xpdf claims to have a utility to convert pdf to plain
text. If memory
I can believe it will extract the text from pdfs that contain text, and
attempt to format it. But if you can find me a utility that will turn a
schematic diagram into plain text, I will be very suprised...
And needless to say, most of the pdfs I want to look at are containers of
scanned schematic diagrams...
-tony