Inside Macintosh: Files /

Chapter 4 - Alias Manager

This chapter describes how your application can use the Alias Manager to establish and resolve alias records, which are data structures that describe file system objects (that is, files, directories, and volumes). You create an alias record to take a "fingerprint" of a file system object, usually a file, that you might need to locate again later. You can store the alias record, instead of a file system specification, and then let the Alias Manager find the file again when it's needed. The Alias Manager contains algorithms for locating files that have been moved, renamed, copied, or restored from backup.

Note

The Alias Manager lets you manage alias records. It does not directly manipulate Finder aliases, which the user creates and manages through the Finder. The chapter "Finder Interface" in Inside Macintosh: Macintosh Toolbox Essentials describes Finder aliases and ways to accommodate them in your application.

The Alias Manager is available only in system software version 7.0 or later. Use the Gestalt function, described in the chapter "Gestalt Manager" of Inside Macintosh: Operating System Utilities, to determine whether the Alias Manager is present.

Read this chapter if you want your application to create and resolve alias records. You might store an alias record, for example, to identify a customized dictionary from
within a word-processing document. When the user runs a spelling checker on the document, your application can ask the Alias Manager to resolve the record to find the correct dictionary.

To use this chapter, you should be familiar with the File Manager's conventions for identifying files, directories, and volumes, as described in the chapter "Introduction to File Management" in this book.

This chapter begins with a description of the Alias Manager, alias records, and the search strategies that the Alias Manager uses to resolve an alias record. Then this chapter shows how you can

• create alias records
• resolve alias records
• store alias records as resources
• get information about the target of an alias record

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Chapter Contents

About the Alias Manager

Alias Records

Search Strategies

Relative Searches

Absolute Searches

Fast Searches

Exhaustive Searches

Using the Alias Manager

Creating Alias Records

Resolving Alias Records

Identifying a Single Target

Identifying Multiple Targets

Maintaining Alias Records

Getting Information From Alias Records

Customizing Alias Records

Alias Manager Reference

Data Structures

Alias Records

Alias Manager Routines

Creating and Updating Alias Records

Resolving and Reading Alias Records

Application-Defined Routines

Filtering Possible Targets

Summary of the Alias Manager

Pascal Summary

Constants

Data Types

Alias Manager Routines

Application-Defined Routine

C Summary

Constants

Data Types

Alias Manager Routines

Application-Defined Routine

Assembly-Language Summary

Data Structure

Trap Macros

Result Codes