Inside Macintosh: Files /

Chapter 4 - Alias Manager

About the Alias Manager

The Alias Manager is the part of the Operating System that helps you to locate specified files, directories, or volumes at a later time. It stores certain information about the target object in an alias record. When you later want the Alias Manager to find the target, you pass it the alias record and other information regarding the type of search to perform. Sometimes, the Alias Manager can find the original file. In other cases, the Alias Manager builds a list of potential matches and allows you (or the user) to select the desired file.

The Alias Manager creates and resolves (that is, finds the targets of) alias records. In general, you should use the Alias Manager to create an alias record whenever you find yourself storing a specific file description, such as filename and parent directory ID. The Alias Manager stores this information and more in the alias record, and it also provides a set of search strategies for resolving the record later. The search strategies are described in "Search Strategies" beginning on page 4-5. You can use the Alias Manager to create, resolve, and (if necessary) update alias records. You can also obtain information about the target of an alias record without actually resolving the alias record.

The Alias Manager can track files and directories across volumes. If the target of an
alias record is on an unmounted AppleShare volume, the Alias Manager automatically mounts the volume when it resolves the alias. If the target object is on an unmounted ejectable volume, the Alias Manager prompts the user to insert the volume.

When the Alias Manager creates an alias record, it allocates the storage, fills in the record, and returns a handle to it. Your application is responsible for storing the record and retrieving it when needed. Your application must also supply strategies for handling various alias-resolution problems, described in "Resolving Alias Records" on page 4-10.

To help you understand and use the Alias Manager, this section provides

• an overview of alias records
• a description of the search strategies the Alias Manager uses to resolve alias records

---

Subtopics

Alias Records

Search Strategies