Inside Macintosh: Networking /

Chapter 9 - AppleTalk Filing Protocol (AFP)

This chapter describes the AppleTalk Filing Protocol (AFP) that allows a workstation on an AppleTalk network to access and manipulate files on an AFP file server, such as an AppleShare server.

Because you can use the native file system to access an AFP server from a workstation,
in most cases you should not need to use AFP directly. For example, few application developers use AFP to access an AppleShare file server because the existing File Manager commands perform most of the functions needed to access and manipulate files on an AppleShare server.

However, if you want to provide functions that are not implemented by the native file system commands or you want to manipulate files on an AFP server other than an AppleShare server, your application can use the AFP programming interface to directly access AFP to send commands to the server. For example, you can use AFP to list the contents of a directory when you need to obtain ProDOS information. You can also use AFP to retrieve or set parameters for a specific file when ProDOS is used.

This chapter describes the programming interface to the workstation portion of AFP only. It does not describe how to implement an AFP server. For information on how to implement an AFP server, see Inside AppleTalk, second edition.

Because AFP is not widely used by application program developers, this chapter provides only the AFP basics. This chapter includes "About" and "Reference" sections. It does not include a "Using" section, as do most of the other chapters in this book. This chapter is included in this book to complete the coverage of the AppleTalk protocol stack.

If you decide to use AFP, it is important to note that to implement an AFP command,
you need information in addition to the information that this chapter provides.
Inside AppleTalk, second edition, and the AppleShare 3.0 Developer's Kit version 3.0, provide information describing the AFP commands and the command block data structure required for each command. The AppleShare 3.0 Developer's Kit includes extensions to AFP not described in Inside AppleTalk.

AFP is built on top of the AppleTalk Session Protocol (ASP) and uses the services of ASP. To use AFP, you should also be familiar with ASP, which is described in the chapter "AppleTalk Session Protocol (ASP)" in this book. For an overview of AFP and how it fits within the AppleTalk protocol stack, read the chapter "Introduction to AppleTalk," which is also in this book.

---

Chapter Contents

About AFP

AFP Reference

Data Structures

AFP Command Block Record

XPP Parameter Block

Routines

Summary of AFP

Pascal Summary

Constants

Data Types

Command Block for AFP Read and AFP Write Commands

XPP Parameter Block for AFP

Routines

C Summary

Constants

Data Types

Command Block for AFP Read and AFP Write Commands

XPP Parameter Block for AFP

Routines

Assembly-Language Summary

Constants

XPP Driver Unit Number

AFP Control Code

AFP Command Codes

Miscellaneous

Data Structures

Parameter Block for General Command Format

Parameter Block for Login Command Format

Parameter Block for AFP Write Command Format

Command Block for the AFP Write Command

Parameter Block for AFP Read Command Format

Command Block for the AFP Read Command

Result Codes