Hierarchical File System APIs

The hierarchical file system (HFS) APIs and the functions they support are part of the OS/400 program. These APIs provide applications with a single, consistent interface to the file systems registered with the hierarchical file system on your AS/400 system. They automatically support the document library services (DLS) file system and the optical file system (QOPT), and they can also support user-written file systems.

With HFS APIs you can work with nonrelational data stored in objects, such as directories and files in existing file systems. You can also perform such tasks as creating and deleting directories and files, reading from and writing to files, and changing the directory entry attributes of files and directories.

• HFS APIs alphabetically by name
• HFS APIs by category

The following diagram shows the relationship of the HFS APIs to your applications and to other file systems:

The links at the bottom of this page provide additional information that you should read before using the HFS APIs. They discuss basic HFS concepts, explain authority to use file systems and their objects, and describe directory entry attributes in detail. Next, if you plan to use the HFS APIs to work with an existing file system, read the documentation provided by the file system for any differences or additional considerations. If you are working with the document library services (DLS) file system, refer to the Office Services Concepts and Programmer's Guide book . If you are working with the optical file system (QOPT), refer to the Optical Support book . If you are not writing applications but instead creating or installing a new file system for other programmers to use with the HFS APIs, turn to User-Written File Systems and HFS.