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File manager

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For the Windows 3.x file manager, see File Manager (Windows).

A file manager or file browser is a computer program that provides a user interface to work with file systems. The most common operations used are create, open, edit, view, print, play, rename, move, copy, delete, attributes, properties, search/find, and permissions. Files are typically displayed in a hierarchy. Some file managers contain features inspired by web browsers, including forward and back navigational buttons.

Some file managers provide network connectivity such as FTP, NFS, SMB or WebDAV. This is achieved either by allowing the user to browse for a file server, connect to it and access the server's file system like a local file system, or by providing its own full client implementations for file server protocols.

Orthodox file managers

Orthodox file managers or "Command based" file managers have three windows (two panels and one command line window).

Orthodox file managers are one of the older families of file managers. They develop and further extend the interface introduced by John Socha's famous[citation needed] Norton Commander for DOS. The concept is more than twenty years old as Norton Commander version 1.0 was released in 1986. Despite their age they are actively developed and dozens of implementations exist for DOS, Unix and Microsoft Windows. Nikolai Bezroukov publishes his own set of criteria for a standard (version 1.2 dated June 1997).[1]

The text-mode Midnight Commander is a well-known orthodox file manager.

Features

The following features define the class of orthodox file managers.

  • They present the user with a two-panel directory view; either panel may be selected to be active and the other then becomes passive. The active panel becomes the working area for delete and rename operations while the passive panel serves as a target for copy and move operations. Panels are shrinkable and if shrunk they expose the terminal window hidden behind them. Normally only the last line of the terminal window (the command line) is visible.
  • They provide close integration with an underlying OS shell via command line and associated terminal window that permits viewing the results of executing the shell command entered on the command line (e.g., via Ctrl-O shortcut in Norton Commander).
  • They provide the user with extensive keyboard shortcuts.
  • The file manager frees the user from having to use the mouse.
  • Users can create their own file associations and scripts that are invoked for certain file types and organize these scripts into a hierarchical tree (e.g., as a user script library or user menu).[citation needed]
  • Users can extend the functionality of the manager via so called User menu or Start menu and extensions menu. Norton Commander introduced the concept of user-defined file associations that is now used in all modern file managers.[citation needed]

Other common features include:

  • Information on the "active" and "passive" panels may be used for constructing commands on the command line. Examples include current file, path to left panel, path to right panel, etc.
  • They provide a built-in viewer for (at least) the most basic file types.
  • They have a built-in editor. In many cases, the editor can extract certain elements of the panels into the text being edited.
  • Many support virtual file systems (VFS) such as viewing compressed archives, or via an FTP connection.
  • They often have the word commander in the name.

An orthodox file manager typically has three windows. Two of the windows are called panels and are symmetrically positioned at the top of the screen. The third is the command line which is essentially a minimized command (shell) window that can be expanded to full screen. Only one of the panels is active at a given time. The active panel contains the "file cursor". Panels are resizable. Each panel can be hidden. Files in the active panel serve as the source of file operations performed by the manager. For example, files can be copied or moved to the passive panel. This gives the user the ability to use only the keyboard with the convenience of the mouse interface. The active panel shows information about the current working directory and the files that it contains. The passive (inactive) panel shows the content of the same or other directory (the default target for file operations). Users may customize the display of columns that show relevant file information. The active panel and passive panel can be switched (often by pressing the tab key). Other user interface elements include:

  1. Path: shows the source/destination location of the directory in use
  2. Information about directory size, disk usage and disk name (usually at the bottom of the panels)
  3. Panel with information about file name, extension, date and time of creation, last modification, permissions (attributes) and other
  4. Info panel with number of files in directory, sum of size of selected files..
  5. Tabbed interface (usually GUI file managers)
  6. Function keys: F1–F10 have all the same functions under all orthodox file managers. Examples: F5 always copies file(s) from the active to the inactive panel, while F6 moves the file.

The introduction of tabbed panels in some file managers (for example Total Commander) made it possible to manipulate more than one active and passive directory at a time.

Orthodox file managers[2] are among the most portable file managers. Examples are available on almost any platform both with command-line interface and graphical user interface. This is unusual among command line managers in that something purporting to be a standard for the interface is published. They are also actively supported by developers. This makes it possible to do the same work on different platforms without much relearning of the interface.

Sometimes they are called dual-pane managers, a term that is typically used for programs such as the Windows File Explorer (see below). But they have three panes including a command line pane below (or hidden behind) two symmetric panes. Furthermore, most of these programs allow using just one of the two larger panes with the second hidden.

In summary, a chief distinguishing feature is the presence of the command line window and direct access to shell via this window - not the presence of two symmetric panes which is relatively superficial.[citation needed]

Examples

Notable examples include:

File-List file manager

Less well-known, but older are the so-called file-list file managers.

Examples include flist which was in use since 1981 on the Conversational Monitor System.[3][4] This is a variant of fulist which originated before late 1978 according to comments by its author Theo Alkema[5]

The flist program provided a list of files in the user's "minidisk"., allowed sorting by any of the file attributes. The file attributes could be passed to scripts or function-key definitions, making it simple to use flist as part of CMS EXEC, EXEC 2 or xedit scripts.

This program ran only on IBM VM/SP CMS, but was the inspiration for other programs, for example filelist[6][7][8] (a script run via the Xedit editor), and programs running on other operating systems. These include a program also called flist running on OpenVMS[9] and fulist (from the name of the corresponding internal IBM program)[10] on Unix.[11]

Directory editors

While this category is known as file managers, an older term is directory editor, which dates back at least to 1978.

There was a directory editor written for EXEC 8 at the University of Maryland, available to other users at that time. The term was used by other developers, e.g., the dired program written by Jay Lepreau in 1980, [12] which ran on BSD. This was in turn inspired by an older program with the same name running on TOPS-20. Dired inspired other programs, e.g., dired the editor script (for emacs and similar editors) as well as ded. [13]

A navigational file manager, also called an "Explorer" type manager, is a newer type of file manager which became prominent because of its integration in Microsoft Windows. The Windows Explorer is a classic representative of the type, using a "navigational" metaphor to represent filesystem locations. Since the advent of GUIs it has become the dominant type of file manager for desktop computers, being used, for example, in all Microsoft Windows products.

Typically it has two panes, with the filesystem tree in the left pane and the current directory in the right one. For Mac OS X, one view in the Finder is an example of a navigational file manager.

The Miller Column browser from GNUstep is a type of Navigational file manager.

Concepts

  • The window displays the location currently being viewed.
  • The location being viewed (the current directory) can be changed by the user, by opening folders, pressing a back button, typing a location, or using additional pane with the navigation tree representing part or all the filesystem.
  • Icons represent files, programs, and directories.

The interface in a navigational file manager often resembles a web browser, complete with back, forward buttons that work with history, and maybe even reload buttons. Sometimes there is also an address bar where the file or directory path (or URI) can be typed.

Moving from one location to another need not open a new window. At the same time several file manager instances can be opened, and they can communicate with each other via drag-and-drop and clipboard operations, so it is possible to view several directories simultaneously and perform cut-and paste operations between instances.

Most navigational managers have two panes with the left pane a tree view of the filesystem. The latter serves as the most common instrument for filesystem navigation. This means that unlike orthodox managers, the two panes are asymmetrical: the first (usually left) provides the tree view of filesystem and the second (usually right) file view of the current directory.

Selecting a directory in the Navigation pane on the left designates it as the current directory, displaying its contents in the Details pane on the right. However, expanding (+) or collapsing (-) a portion of the tree without selecting a directory will not alter the contents of the right pane unless, when collapsing, the current directory is a subdirectory in the path that is being rolled up, in which case the selection is refocused on the collapsed parent directory, thus altering the contents of the Details pane.

File operations are based on drag-and-drop and editor metaphors: users can select and copy files or directories into the clipboard and then paste them in a different place in the filesystem or even in a different instance of file manager.

Examples

Notable examples include:

Spatial file manager

Main article: Spatial file manager
The Nautilus file manager has a spatial mode. Each of these windows displays an open folder.

Spatial file managers use a spatial metaphor to represent files and folders as if they were real physical objects. A spatial file manager imitates the way people interact with physical objects.

Some ideas behind the concept of a spatial file manager are:

  1. A single window represents each opened folder.
  2. Each window is unambiguously and irrevocably tied to a particular folder.
  3. Stability: files, folders, and windows go where the user moves them, stay where the user puts them ("preserve their spatial state"), and retain all their other "physical" characteristics (such as size, shape, color and location).
  4. The same item can only be viewed in one window at a time.

As in navigational managers, when a folder is opened, the icon representing the folder changes—perhaps from an image showing a closed drawer to an opened one, perhaps the folder's icon turns into a silhouette filled with a pattern—and a new window is opened.

Examples

Examples of file managers that to some extent use a spatial metaphor include:

Dysfunctional spatial file managers:

  • Windows Explorer in Windows 95 was set as a spatial file manager model by default; but because it also worked as a navigational file manager, folders could be opened in multiple windows, which made it fail all the above criteria. Later versions gradually abandoned the spatial model.
  • Apple's Finder in Mac OS X — much like in Explorer, the integration of spatial and navigational mode means that the spatial mode does not actually work.[14]

3D file managers

File System Visualizer, one example of a 3D file manager.

Some projects have attempted to implement a three-dimensional method of displaying files and directory structures. The exact implementation tends to differ between projects, as three-dimensional file browsing has not yet become popular and thus there are no common standards to follow.

Examples

Examples of three-dimensional file managers include:

  • fsn, for Silicon Graphics' IRIX systems, notably featured prominently in one scene from the film Jurassic Park, as a representation of Unix systems.
  • File System Visualizer, or fsv, an open source clone of fsn for modern Unix-like systems.
  • BumpTop, a file manager using a three dimensional representation of a desktop with realistic physics, intended for use with a stylus and touchscreen.
  • Real Desktop, a desktop replacement with similarities to BumpTop.

Web based file managers

Web based file managers are typically scripts written in either PHP, Ajax, Perl, ASP or any other server side languages. When installed on a local server or on a remotely hosted server they allow files and folders located there to be managed and edited without the need for FTP Access.

More advanced, and usually commercially distributed, web based file management scripts allow the administrator of the file manager to configure secure, individual user accounts, each with individual account permissions. Authorized users have access to documents stored on the server or in their individual user folders anytime from anywhere via a web browser.

A web based file manager can serve as an organization's digital repository. For example, documents, digital media, publishing layouts, and presentations can be stored, managed, and shared between customers, suppliers, remote workers or just internally.

A 3D file manager is featured in Jurassic Park, during a scene where Lex desperately tries to find an executable file, while a Velociraptor tries to force its way into the command center. The 3D file manager, fsn (mentioned above), was built on top of a Unix system (Silicon Graphics, Inc's IRIX).

See also

References

  1. ^ "OFM standards".
  2. ^ "Home of the OFM standard".
  3. ^ "Discussion of VM/CMS FLIST showing screenshot".
  4. ^ "Textual description of VM/CMS FLIST".
  5. ^ "email by Theo Alkema to Lynn Wheeler". 1978-10-10. Retrieved 2008-01-31.
  6. ^ "Comment on original author of fulist".
  7. ^ "Description of FILELIST".
  8. ^ "User comparing FLIST to FILELIST".
  9. ^ "FLIST - file manager for VAX/VMS".
  10. ^ "User comparing FULIST and FLIST".
  11. ^ "FULIST for Unix".
  12. ^ "Abstract for dired 3.05".
  13. ^ "DED - Directory Editor".
  14. ^ Siracusa, John (2007-10-28). "Mac OS X 10.5 Leopard: the Ars Technica review: The Finder: An application divided against itself". Retrieved 2008-04-20.
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