If the XDR header files are missing you will not be able to compile GRAPE programs, in this case you should get the RPC package which is freely available from Sun and install it on the system.
The XDR library routines might not be contained in the C library, in this case you probably have to link your program with the sun library (-lsun).
Please consider the XDR man pages or ask the system operator if you have one of these problems.
Copyright © by the Sonderforschungsbereich 256 at the Institut für Angewandte Mathematik, Universität Bonn.