Briefcase (Microsoft Windows)
Encyclopedia
In Microsoft Windows
, the Briefcase is a special folder
that supports simple two-way file synchronization
between itself and another folder. The Briefcase is designed for mobile PC users so that they may transfer it to a removable drive and have it synchronize with the computer to which the removable drive is attached. It follows the same metaphor as the file
and file folder
and then, while the file management tasks are performed by Windows Explorer, the briefcase behaves just like another folder
, i.e. with support for copy-paste and drag-and-drop
. It has additional functions and toolbar buttons for updating out-of-sync files. The Windows Briefcase was introduced in Windows 95
.
If there are differences between the copies, the Briefcase shows a dialog box with an icon and a description indicating the action it will take when synchronizing; that is, whether it will replace the copy in the Briefcase with the external file or vice versa. The action the Briefcase will take is configurable by right clicking the icon. For example, users can skip synchronizing individual items by selecting the Skip action upon right clicking the icon. For items deleted in either the Briefcase or the main original folder, the Briefcase can create a copy of the missing item. Users can also sync individual items in the Briefcase by selecting the item first and then clicking the Update button instead of Update All.
The update status of each item is stored in the Briefcase. If any item does not link to any original item outside the briefcase, (for example when the drive containing the briefcase is inserted in a secondary computer, or the original has been deleted in the main computer) it is called an orphan.
In addition to this file, a second Hidden/System file serves as the Briefcase database. This file is Briefcase Database. Except for its first four bytes (the characters DDSH), the format of this database is specialized for Briefcases; a tool to view and edit it does not appear to exist.
If the briefcase medium becomes full during an Update, there will be no space for writing the updated briefcase database. This has the effect of making many of the folders and files orphans, with no easy way to restore their link with their counterparts on the source medium.
Such limitations (and others) make briefcase files very brittle, easily corrupted. This limits robustness as a folder and file backup mechanism.
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, the Briefcase is a special folder
Special Folders
On Microsoft Windows, a special folder is a folder which is presented to the user through an interface as an abstract concept, instead of an absolute folder path...
that supports simple two-way file synchronization
File synchronization
File synchronization in computing is the process of ensuring that computer files in two or more locations are updated via certain rules....
between itself and another folder. The Briefcase is designed for mobile PC users so that they may transfer it to a removable drive and have it synchronize with the computer to which the removable drive is attached. It follows the same metaphor as the file
Computer file
A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...
and file folder
File folder
A file folder is a kind of folder that holds loose papers together for organization and protection. File folders usually consist of a sheet of heavy paper stock or other thin, but stiff, material which is folded in half, and are used to keep paper documents...
and then, while the file management tasks are performed by Windows Explorer, the briefcase behaves just like another folder
Directory (file systems)
In computing, a folder, directory, catalog, or drawer, is a virtual container originally derived from an earlier Object-oriented programming concept by the same name within a digital file system, in which groups of computer files and other folders can be kept and organized.A typical file system may...
, i.e. with support for copy-paste and drag-and-drop
Drag-and-drop
In computer graphical user interfaces, drag-and-drop is the action of selecting a virtual object by "grabbing" it and dragging it to a different location or onto another virtual object...
. It has additional functions and toolbar buttons for updating out-of-sync files. The Windows Briefcase was introduced in Windows 95
Windows 95
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products...
.
Overview
The Windows Briefcase synchronizes files and folders within itself with those in any other folder, even on a removable writable media or the network. It is intended for users with portable media or multiple computers. To use the Briefcase, users only need to use Windows Explorer and then drag or copy their files into the Briefcase once. Any further changes to either the files on disk or those in the Briefcase are synchronized whenever the user right-clicks on the briefcase and selects Update All.If there are differences between the copies, the Briefcase shows a dialog box with an icon and a description indicating the action it will take when synchronizing; that is, whether it will replace the copy in the Briefcase with the external file or vice versa. The action the Briefcase will take is configurable by right clicking the icon. For example, users can skip synchronizing individual items by selecting the Skip action upon right clicking the icon. For items deleted in either the Briefcase or the main original folder, the Briefcase can create a copy of the missing item. Users can also sync individual items in the Briefcase by selecting the item first and then clicking the Update button instead of Update All.
The update status of each item is stored in the Briefcase. If any item does not link to any original item outside the briefcase, (for example when the drive containing the briefcase is inserted in a secondary computer, or the original has been deleted in the main computer) it is called an orphan.
Internals
Most special folders in Windows (such as Briefcase folders) have a Hidden file (with System attribute) Desktop.ini. They may also have Registry entries describing them. The Desktop.ini for a Briefcase contains the following lines:
[.ShellClassInfo]
CLSID={85BBD920-42A0-1069-A2E4-08002B30309D}
ConfirmFileOp=0
In addition to this file, a second Hidden/System file serves as the Briefcase database. This file is Briefcase Database. Except for its first four bytes (the characters DDSH), the format of this database is specialized for Briefcases; a tool to view and edit it does not appear to exist.
Limitations
When a user wishes to sync a file with one in another folder, the filename must be exactly the same. If any item is renamed or moved, it splits from the original, is no longer synchronized and becomes an orphan. If an item is deleted, the associated copy by default is deleted as well when using Update All.If the briefcase medium becomes full during an Update, there will be no space for writing the updated briefcase database. This has the effect of making many of the folders and files orphans, with no easy way to restore their link with their counterparts on the source medium.
Such limitations (and others) make briefcase files very brittle, easily corrupted. This limits robustness as a folder and file backup mechanism.