The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 1994
Filed:
Jun. 10, 1991
David Hendricks, Menlo Park, CA (US);
Evan Adams, San Leandro, CA (US);
Tom Lyon, Palo Alto, CA (US);
Terrence C Miller, Menlo Park, CA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
In a computer system having a hierarchical file structure, a file system is provided which permits users of the system to share a file hierarchy and also have a private hierarchy in which files are automatically copied to as they are modified. Through the system of the present invention, a directory appears to the user as a single directory but may actually comprise files originating from a number of directories which are connected to one another through search links. Each directory has a search link associated with it which contains the path name of the back layer or directory behind it. The first layer seen through the system of the present invention is the front layer, private to the user. The back layers behind the front layer and connected to the front layer through the search links are shared layers accessible to multiple users. Thus transparent to the user of the directory accessible comprises multiple layers comprising shared and private files. The system further provides a copy-on-write feature which protects the integrity of the shared files by automatically copying a shared file into the users private layer when the user attempts to modify a shared file in a back layer.