Text editor From Wikipedia, the free encyclopedia.

Notepad is the standard text editor for Microsoft Windows

A text editor is a piece of computer software for editing plain text. It is distinguished from a word processor in that it does not manage document formatting or other features commonly used in desktop publishing.

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.

Some text editors are small and simple, while others offer a broad and complex range of functionality. For example, Unix and Unix-like operating systems have the vi editor (or a variant), but many also include the Emacs editor to edit text as well. Microsoft Windows systems come with the very simple Notepad, though many people (especially programmers) use a more complete program. Under Apple Macintosh's classic Mac OS, there was the native SimpleText, which was replaced or supplemented by WorldText. Under Mac OS X, TextEdit is the included default editor, which saves files in text and other formats. BBEdit is the most popular 3rd party text and source code editor, which is especially popular for creating HTML content. Windows and Mac OS ports of Emacs also exist.

History

Before text editors existed, computer text was punched into Hollerith cards, keypunch machines. The text was carried as a physical box of thin cardboard cards, and read into a card-reader.

The first text editors did not provide a window or screen-oriented display. They provided short commands to print sections of the file. Usually an "edit cursor", an imaginary insertion point, was moved through the file, and short segments of the file could be printed to see the changes. These "character-based text editors" were considered revolutionary improvements over keypunch machines. It was now impossible to drop a box of punch cards.

When computer terminals with video screens became inexpensive, screen-based text editors became common. One of the earliest is "VI", still a standard editor for UNIX and Linux operating systems. The ease of use of these editors motivated many of the early purchases of video terminals.

Types of text editors

Text editors geared for professional computer users place no limit on the size of the file being opened. In particular, they start quickly even when editing large files, and can edit files that are too large to fit the computer's main memory. Simpler text editors often just read files in an array in RAM. On larger files, this is slow, and very large files often do not fit.

The ability to read and write very large files is needed by many professional computer users. For example, system administrators may need to read long log files. Programmers may need to change large source code, or examine naturally large texts, such as an entire dictionary placed in a single file.

Some text editors include specialized computer languages to customize the editor. For example, EMACS can be customized by programming in Lisp. These usually permit the editor to simulate the keystroke combinations and features of other editors, so that users don't have to learn the native command combinations.

Many text editors for software developers include source code syntax highlighting and automatic completion to make a programming language easier to read and write. Programming editors often permit one to select the name of a subprogram or variable, and then jump to its definition and back. Often an auxiliary utility, like ctags is used to locate the definitions.

Some editors include special features and extra functions, for instance,

• Source code editors

• Folding editors

• IDEs

• HTML editors

• Outliners

are packages with text editors included, usually with extra functionality.