I/O operations performed on a basic Channel are sequential. This means that if you write more than one Object to a Channel, each new Object's textual description is simply appended to the previous one. You can store any number of Objects in this way, subject only to the storage space you have available.
After you read an Object back from a basic Channel, the
Channel is ``positioned'' at the end of that Object's
textual description. If you then perform another read, you will
read the next Object's textual description and therefore
retrieve the next Object. This process may be repeated to read
each Object in turn. When there are no more Objects to be
read, AST_READ will return the value AST__NULL to indicate an
end-of-file.
AST A Library for Handling World Coordinate Systems in Astronomy