OSI/FTAM Programming Guide

ISO FTAM Concepts
HP NonStop OSI/FTAM Programming Guide—528612-001
2-26
File-Access Actions
FADU identities are categorized into three groups according to the method of access to
nodes in a file. Table 2-6 describes the FADU-identity groups, the FADU-identity values
that you can use in each group, and the associated methods of access.
File-Access Actions
The VFS defines actions that can be performed on files in the file storage system.
Document types and constraint sets limit the actions permitted for specific files.
Table 2-7 shows the file-access actions defined by the VFS.
Configuration of Default Values for VFS Parameters
The VFS interface of FTAM has a set of attributes that defines the contents of a file
(called "document type" in FTAM), including the access constraints, the data transfer
characteristics (defined by format effectors, maximum string length, and string
significance of FTAM), and format translations. These attributes in OSI/FTAM are
based on National Institute of Science and Technology (NIST) agreements.
FILCONF Interface
FILCONF aids in configuring the VFS attributes to meet the expectations of a remote
system.
Table 2-6. FADU-Identity Groups
Group Name FADU-Identity Values Method of Access
Traversal Begin, first, next, last, end. Sequential access permitting you to
traverse the file from the first FADU to
the last FADU.
Reverse traversal Begin, first, previous, last,
end.
Sequential access permitting you to
traverse the file from the last FADU to
the first FADU.
Random Current, node-name,
sequence of node names,
node number.
Random access permitting you to select
any FADU by the FADU ID indicated in
a read, write, or locate request.
Table 2-7. File-Access Actions
Action Description
Locate Locates a FADU, specified with one of the FADU identities specified in
Table 2-5
on page 2-25.
Read Reads a FADU.
Insert Creates a new FADU and inserts it into the file structure.
Replace Replaces the contents of a FADU.
Extend Adds data to the end of an existing FADU.
Erase Removes a FADU from the file structure.