File viewer
Encyclopedia
A file viewer is application software
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...

 that presents the data stored in a computer 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...

 in a human-friendly form. The file contents are generally displayed on the screen
Display device
A display device is an output device for presentation of information in visual or tactile form...

, or they may be printed
Computer printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...

. Also, they may be read aloud using speech synthesis
Speech synthesis
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware...

.

Overview

File viewers do not edit files, yet it is common for them to be able to save data in a different file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

, or to copy information from the viewed file to the system-wide clipboard
Clipboard
A clipboard is a thin, rigid board with a clip at the top for holding paper in place. A clipboard is typically used to support paper with one hand while writing on it with the other, especially when other writing surfaces are not available.-Other uses:...

.

File viewers have to have sufficient knowledge about the format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

 of the file to be viewed. Even plain text
Plain text
In computing, plain text is the contents of an ordinary sequential file readable as textual material without much processing, usually opposed to formatted text....

 files are not so simple — file viewers may have to handle different code page
Code page
Code page is another term for character encoding. It consists of a table of values that describes the character set for a particular language. The term code page originated from IBM's EBCDIC-based mainframe systems, but many vendors use this term including Microsoft, SAP, and Oracle Corporation...

s and newline
Newline
In computing, a newline, also known as a line break or end-of-line marker, is a special character or sequence of characters signifying the end of a line of text. The name comes from the fact that the next character after the newline will appear on a new line—that is, on the next line below the...

 styles.

A fundamental type of file viewer are filter
Filter (Unix)
In Unix and Unix-like operating systems, a filter is a program that gets most of its data from its standard input and writes its main results to its standard output . Unix filters are often used as elements of pipelines...

s that translate binary files into plain text (one example antiword
Antiword
Antiword is a free software reader for proprietary Microsoft Word documents, and is available for most computer platforms. Antiword can convert the documents from Microsoft Word version 2, 6, 7, 97, 2000, 2002 and 2003 to plain text, PostScript, PDF, and XML/DocBook .-Overview:The Word format is...

). However, depending on the competence of the translating routines, some information may be lost. Disassembler
Disassembler
A disassembler is a computer program that translates machine language into assembly language—the inverse operation to that of an assembler. A disassembler differs from a decompiler, which targets a high-level language rather than an assembly language...

s also fall in this category.

Another common type of file viewer is a picture viewer that can display picture files of various formats. Common features here are thumbnail
Thumbnail
Thumbnails are reduced-size versions of pictures, used to help in recognizing and organizing them, serving the same role for images as a normal text index does for words...

 preview and creation, and image zooming.

For more complex or proprietary file formats, file viewers are usually provided by the same companies that make the editing software using those formats (viewers may be distributed free of charge, while editors have to be bought).

A file viewer is limited-functionality software in the sense that it does not have a capability to create a file, or modify the content of an existing one. Instead, it is used only to display or print the content.

The primary reason behind this missing functionality is often due to marketing and control. For example, a popular software program, Adobe Acrobat
Adobe Acrobat
Adobe Acrobat is a family of application software developed by Adobe Systems to view, create, manipulate, print and manage files in Portable Document Format . All members of the family, except Adobe Reader , are commercial software, while the latter is available as freeware and can be downloaded...

, can be used to create content for most computer platforms, under various operating systems. To ensure that people can access the documents created with Adobe Acrobat, the software publisher created a viewer program, the Acrobat Reader, and made it available for free. This viewer application allows the content created by the proprietary authoring software to be readable on all supported operating-system platforms, free of charge, thus making it a more attractive solution.

There are many products that can qualify as a file viewer: Microsoft Word
Microsoft Word
Microsoft Word is a word processor designed by Microsoft. It was first released in 1983 under the name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other platforms including IBM PCs running DOS , the Apple Macintosh , the AT&T Unix PC , Atari ST , SCO UNIX,...

 viewer or Microsoft PowerPoint
Microsoft PowerPoint
Microsoft PowerPoint, usually just called PowerPoint, is a non-free commercial presentation program developed by Microsoft. It is part of the Microsoft Office suite, and runs on Microsoft Windows and Apple's Mac OS X operating system...

 viewer, and the OpenOffice equivalents are examples. In a sense, a web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...

 is a type of file viewer, which translates, or renders, the HTML
HTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....

 markups into a human-friendly presentation. Although HTML is plain text, viewing an HTML file in a browser and in a text editor
Text editor
A text editor is a type of program used for editing plain text files.Text editors are often provided with operating systems or software development packages, and can be used to change configuration files and programming language source code....

 produces significantly different results.

Although web browsers are arguably the best file viewer, since they support many graphic, multimedia, and document formats, they are likely to always be somewhat lacking in the output quality and feature performance of more specialized software packages. Creating and using alternative publishing systems and their accompanying file viewers still makes a lot of business sense, given the content and presentation control they provide.

Streaming media

There are also types of data that are not intended for static display — these incorporate the time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

 dimension. Viewers for such formats are named players. But the essence is the same — presenting file contents in human-friendly form (i.e. displaying video on the screen as intended, or playing sound through loudspeakers). And the same consideration of different file formats is present.

Microsoft Office Documents

  • Microsoft Word Viewer
    Microsoft Word Viewer
    Microsoft Word Viewer is a standalone freeware program for Microsoft Windows that lets users who do not own Microsoft Word view and print documents that were created in Microsoft Office....

  • Microsoft Excel Viewer
  • FreeFileViewer
  • Free Opener

PDF Files


Binary Files

  • Text viewer with *Incremental search for huge files of up to several 100 MByte
  • frhed (win)
  • YaHEbwinPy (multi-platform)
  • Beye
  • lfex (lx)
  • fb (*)
  • Midnight Commander
    Midnight Commander
    GNU Midnight Commander is a free cross-platform orthodox file manager and a clone of Norton Commander originally created by Miguel de Icaza.Midnight Commander is licensed under the terms of the GNU General Public License.-Design:...

  • ExifTool

See also

  • Binary file#Viewing binary files
  • Electronic document
    Electronic document
    An electronic document is any electronic media content that are intended to be used in either an electronic form or as printed output....

  • Image viewer
    Image viewer
    An image viewer or image browser is a computer program that can display stored graphical image; it can often handle various graphics file formats...

  • Media player
  • Text editor
    Text editor
    A text editor is a type of program used for editing plain text files.Text editors are often provided with operating systems or software development packages, and can be used to change configuration files and programming language source code....

  • Web browser
    Web browser
    A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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