SPLITPIPE(5) Manual Page

NAME

splitpipe - data format used by splitpipe(1) and joinpipe(1)

SYNOPSIS

The splitpipe data format is used by splitpipe(1) and joinpipe(1) to allow piped data to span volumes.

DEFINITIONS

session: All data sent to splitpipe. In other words, the full pipe.
volume: Sessions are split into volumes, each volume might be a CD, DVD, disk or file.
stretch: Each volume consists of stretches. Each stretch includes its own length, excluding its own three byte header. A stretch also has a type, each of which has its own meaning. One of these types is data.

STRETCHES

Currently, the following stretch types have been allocated, followed by their assigned type number:

Session Name (0): Optional name given to this session. Intended for human consumption.
Session UUID (1): Used to verify that a volume belongs to a session
Volume Number (2): Incremented by 1 for each volume, starting at zero, to verify the proper order of volumes within a session.
Volume EOF (3): Designates the end of a volume. Not to be used on the last volume!
Data (4): Actual content of the pipe
MD5 Checksum (5): Running MD5 checksum of all Data stretch contents up to this stretch.
SHA1 Checksum (6): Running SHA1 checksum of all Data stretch contents up to this stretch.
Session EOF (7): Designates end of a session. Implies a Volume EOF.

FORMAT

Each stretch starts with 16 bits in which its size is stored, in network byte order. This is followed by 8 bits which describe the type.

SEMANTICS

The reader of a splitpipe stream is free to ignore optional stretch types, but the following behaviour is mandatory.

Each volume has, before the first Data stretch, at least a UUID and Volume stretch. A volume shall end with a Volume EOF stretch, except when it is the last volume in a session, in which case it shall end on a Session EOF.

MD5 or SHA1 checksum stretches may be interleaved at any point during the stream, but shall at least be included at the end of each volume.

AUTHOR

Written by Netherlabs Computer Consulting BV, bert hubert, <ahu@ds9a.nl>

RESOURCES

Website: http://ds9a.nl/splitpipe