Page Break
Encyclopedia
A page break is a marker in an electronic document
that tells the document interpreter that the content which follows is part of a new page. A page break causes a form feed to be sent to the printer during spooling of the document to the printer.
control character
. It forces the printer
to eject the current page and to continue printing at the top of another. Often, it will also cause a carriage return
. The form feed character code is defined as 12 (0xC in hexadecimal
), and may be represented as control+L or ^L. In the C programming language (and other languages derived from C), the form feed character may be represented as
.
Form feed is seldom used when programming with modern printers in modern operating environments like Windows
, Unix
, Linux
or Mac OS
. Instead, form feeds are generated by having the printing program call a form feed API
function. For example, when printing using the .NET Framework
, the
The form feed character is sometimes used in plain text files of source code as a delimiter for a page break, or as marker for sections of code. Some editors, in particular emacs
, have built-in commands to page up/down on the form feed character. This convention is predominantly used in Lisp code, and is also seen in Python
source code.
In Usenet
, the form feed character is used by several newsreaders as a "spoiler character", causing them to automatically hide the following text until prompted, as a way to prevent spoiler
s from being inadvertently revealed. The precise behavior depends on the client displaying the article: for example, Gnus
displays "Next page..." in boldface, and switches to a second screen to display text after the form feed; slrn
displays all non-space characters following the form feed as asterisk
s; Dialog turns the font and background color red between form feeds; and XRN simply inserts blank lines to fill up the remainder of the article display area so the user must scroll down to reveal the spoiler. This use of the form feed character is not supported by all newsreaders, and is not standardized, although it has appeared in a draft of a Usenet Best Practices document by the IETF's USEFOR working group, as a feature that user agents should (but are not required to) support.
Document
The term document has multiple meanings in ordinary language and in scholarship. WordNet 3.1. lists four meanings :* document, written document, papers...
that tells the document interpreter that the content which follows is part of a new page. A page break causes a form feed to be sent to the printer during spooling of the document to the printer.
Form feed
Form feed is an ASCIIASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
control character
Control character
In computing and telecommunication, a control character or non-printing character is a code point in a character set, that does not in itself represent a written symbol.It is in-band signaling in the context of character encoding....
. It forces the printer
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...
to eject the current page and to continue printing at the top of another. Often, it will also cause a carriage return
Carriage return
Carriage return, often shortened to return, refers to a control character or mechanism used to start a new line of text.Originally, the term "carriage return" referred to a mechanism or lever on a typewriter...
. The form feed character code is defined as 12 (0xC in hexadecimal
Hexadecimal
In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
), and may be represented as control+L or ^L. In the C programming language (and other languages derived from C), the form feed character may be represented as
'\f'Escape character
In computing and telecommunication, an escape character is a character which invokes an alternative interpretation on subsequent characters in a character sequence. An escape character is a particular case of metacharacters...
.
Form feed is seldom used when programming with modern printers in modern operating environments like Windows
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...
, Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
or Mac OS
Mac OS
Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
. Instead, form feeds are generated by having the printing program call a form feed API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
function. For example, when printing using the .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
, the
PrintPageEventArgs.HasMorePages property is used to indicate a form feed is desired.The form feed character is sometimes used in plain text files of source code as a delimiter for a page break, or as marker for sections of code. Some editors, in particular emacs
Emacs
Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...
, have built-in commands to page up/down on the form feed character. This convention is predominantly used in Lisp code, and is also seen in Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
source code.
In Usenet
Usenet
Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
, the form feed character is used by several newsreaders as a "spoiler character", causing them to automatically hide the following text until prompted, as a way to prevent spoiler
Spoiler (media)
Spoiler is slang for any element of any summary or description of any piece of fiction that reveals any plot element which will give away the outcome of a dramatic episode within the work of fiction, or the conclusion of the entire work. It can also be used to refer to any piece of information...
s from being inadvertently revealed. The precise behavior depends on the client displaying the article: for example, Gnus
Gnus
Gnus is a message reader running under GNU Emacs and XEmacs. It supports reading and composing both news and e-mail.Gnus blurs the distinction between news and e-mail, treating them both as "articles" that come from different sources. News articles are kept separate by group, and e-mail can be...
displays "Next page..." in boldface, and switches to a second screen to display text after the form feed; slrn
Slrn
slrn is an open source text-based news client. It was originally developed for Unix-like operating systems, but is now available for many other operating systems, including Microsoft Windows....
displays all non-space characters following the form feed as asterisk
Asterisk
An asterisk is a typographical symbol or glyph. It is so called because it resembles a conventional image of a star. Computer scientists and mathematicians often pronounce it as star...
s; Dialog turns the font and background color red between form feeds; and XRN simply inserts blank lines to fill up the remainder of the article display area so the user must scroll down to reveal the spoiler. This use of the form feed character is not supported by all newsreaders, and is not standardized, although it has appeared in a draft of a Usenet Best Practices document by the IETF's USEFOR working group, as a feature that user agents should (but are not required to) support.