xforms' glcanvas in linux

hello, I got a problem using xforms’s glcanvas in linux. the problem is the linux version of xforms doesn’t compile with GL (linux are using Mesa’s GL).
the documentation of xforms tell me to extract the object file of libforms.so.0.89, then recompile it with “-lGL” as the linking.
I am kind of new to linux, some one tell me to use “ar …” to extract the object file, I don’t know how to start.
Would you please help me in detail? Thankx a lot.
From Alan.