An eXternal Data Representation (XDR) is a data representation standard that is independent of languages, operating systems, manufacturers, and hardware architecture. This standard enables networked computers to share data regardless of the machine on which the data is produced or consumed. The XDR language permits transfer of data between diverse computer architectures.
An XDR approach to standardizing data representations is canonical. That is, XDR defines a single byte (big endian), a single floating-point representation (IEEE), and so on. Any program running on any machine can use XDR to create portable data by translating its local representation to the XDR standards. Similarly, any program running on any machine can read portable data by translating the XDR standard representations to its local equivalents.
The XDR standard is the backbone of the RPC, because data for remote procedure calls is sent using the XDR standard.
To use XDR routines, C programs must include the <RPC\XDR.H> header file, which is automatically included by the <RPC\RPC.H> header file.