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. They are very useful for speeding up interaction with files. The most common operations on files are create, open, edit, view, print, play, rename, move, copy, delete, attributes, properties, search/find, and permissions.

Typically files are displayed in a hierarchy. File managers may contain features inspired by web browsers, including forward and back navigational buttons.

Some browsers may also provide network connectivity, e.g. via FTP, NFS, SMB or WebDAV, either by allowing the user to browse for servers and connect to them and then accessing the file system from the server the same way it accesses local file systems, or by providing its own full client implementations for file server protocols.

Some file managers also provide the ability to extend operations using user written scripts. This is a typical feature of Orthodox file managers.

Contents

[edit] Orthodox file managers

Orthodox file managers or "Commander-like" file managers have three windows (two panels and one command line window).

They are one of the older families of file managers. They develop and further extend the interface introduced by John Socha's famous Norton Commander for DOS. That 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. A public standard (version 1.2 dated June 1997) is available from Nikolai Bezroukov's website.[1]

The following features define the class of Orthodox file managers:

  • They present the user with a two-panel directory view consisting of one active and one passive panel. The latter always serves as a target for file 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 can be used without or with minimal use of 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: Example F5 always copies file(s) from active to 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 the 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 GUI interface. This is the only type of command line managers that have a published standard of the interface (and actively supported by developers). This makes 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). It is technically incorrect since they have three windows including a command line window below (or hidden behind) two symmetric panels. Command line windows play a very prominent role in the functionality of this type of file manager. Furthermore, most of these programs allow using just one pane with the second one hidden. Focusing on 'dual panes' may be misleading; it is the combination of all of these features which is important.

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:

[edit] 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]

[edit] 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, which 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]

[edit] Navigational file manager

A navigational file manager is a newer type of file managers which became prominent due to the popularity of Microsoft Windows. It uses a "navigational" metaphor to represent filesystem locations and also often called "Explorer" type of file managers. The Windows Explorer is a classic representative of the type. 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, one with the current directory and one with the filesystem tree. For Mac OS X, the Finder is an example of a navigational file manager.

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

[edit] 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 instances of manager can be opened and they can communicate with each other via drag and drop and clipboard 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 second pane a tree view of the filesystem. The latter serves as the most common instrument for filesystem navigation. That 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.

When a directory of the tree is selected it becomes current and the content of the second (right) pane changes to the files in the current directory.

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:

  • Windows Explorer
  • Mac OS Finder
  • XTree

[edit] Spatial file manager

 This article needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (April 2007)
The Nautilus file manager has a spatial mode. Each of these windows displays an open folder.
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 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 in 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]

[edit] 3D file managers

File System Visualizer, one example of a 3D file manager.
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 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.
  • Knexus, a real-time 3D virtual library interface. 'Books' in the library act as symbolic links to files. The organizational structure is free-form similar to a three-dimensional Mind Map.

[edit] Web based file managers

Web based file managers are typically scripts written in either PHP, Perl, Asp or AJAX. 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.

[edit] See also

[edit] 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 on 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 on 2008-04-20.

[edit] External links