Using Fork Commands
AFP provides these fork-level commands:
The AFP client uses the
FPGetForkParms command to read a fork’s parameters.
FPSetForkParms command is used to modify a fork’s parameters.
FPOpenFork command is used to open either fork of an existing file. This command returns an open fork reference number, which is used in subsequent commands for this open fork.
FPReadExt commands are used to read the contents of the fork. The
FPReadExt command differs from the
FPRead command in that the
FPReadExt command is prepared to handle large values that may be returned for volumes greater than 4 GB in size.
FPWriteExt commands are used to write to a fork. The
FPWriteExt command differs from the
FPWrite command in that the
FPWriteExt command is prepared to handle the large values that are required for writing to volumes greater than 4 GB in size.
FPFlushFork command is used to request that server write to disk any of the fork’s data that is in the server’s internal buffers.
FPByteRangeLockExt commands are used to lock ranges of bytes in the fork. The
FPByteRangeLockExt command differs from the
FPByteRangeLock command in that the
FPByteRangeLockExt command is prepared to handle large values that are required for locking ranges on volumes greater than 4 GB in size. Locks allow multiple users to share a file’s open fork. Locking a range of bytes prevents other AFP clients from reading or writing data within the specified range. If an AFP client locks a byte range, that range is reserved for exclusive manipulation by the client that placed the lock.
FPCloseFork command is used to close an open fork. This command invalidates the open fork reference number that was assigned when the fork was opened.