ed is the standard text editor on the Unix operating system. 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 Unix (officially trademarked as UNIX, sometimes also written as Unix with Small caps) is a computer ed was originally written by Ken Thompson and contains one of the first implementations of regular expressions. Kenneth Lane Thompson (born February 4 1943) commonly referred to as Ken Thompson (or simply In Computing, regular expressions provide a concise and flexible means for identifying strings of text of interest such as particular characters words or patterns of characters Prior to that implementation, the concept of regular expressions was only formalized in a mathematical paper, which Ken Thompson had read. ed was influenced by an earlier editor known as QED from University of California at Berkeley, Ken Thompson's alma mater. QED is a line-oriented computer Text editor that was designed by Butler Lampson and L The University of California Berkeley (also referred to as Cal, Berkeley and UC Berkeley) is a major research university located in Berkeley Alma mater is Latin for "nourishing mother" It was used in Ancient Rome as a title for the mother Goddess, and in Medieval ed went on to influence ex, which in turn spawned vi. ex, short for EXtended is a Line editor for Unix systems The original ex was an advanced version of the standard Unix editor ed, included vi is a screen-oriented Text editor written by Bill Joy in 1976 for an early BSD release The non-interactive Unix commands grep and sed were inspired by common special uses of ed; their influence is visible in the design of the programming language AWK, which in turn inspired aspects of Perl. grep is a command line text search utility originally written for Unix. sed ( S tream ED itor refers to a Unix utility which (a parses text files and (b implements a Programming language which can apply textual transformations AWK is a general purpose Programming language that is designed for processing text-based data either in files or data streams and was created at Bell Labs in the 1970s NOTES FOR EDITORS "Perl" is not an acronym (read the "Name" section below

Famous for its terseness, ed gives almost no visual feedback. For example, the message that ed will produce in case of error, or when it wants to make sure the user wishes to quit without saving, is "?". It does not report the current filename or line number, or even display the results of a change to the text, unless requested. This terseness was appropriate in the early versions of Unix, when consoles were teletypes, modems were slow, and memory was precious. A teleprinter ( Modem (from mo dulator- dem odulator is a device that modulates an analog carrier signal to encode Digital information As computer technology improved and these constraints were loosened, editors with more visual feedback became the standard.

In current practice, ed is rarely used interactively, but does find use in some shell scripts. A shell script is a script written for the shell, or Command line interpreter, of an Operating system. For interactive use, ed was subsumed by the sam, vi and Emacs editors in the 1980s. Sam is a multi-file Text editor originally designed at Bell Labs by Rob Pike (with the help of Ken Thompson and other Unix developers in the vi is a screen-oriented Text editor written by Bill Joy in 1976 for an early BSD release Emacs is a class of feature-rich Text editors usually characterized by their extensibility The 1980s was the decade spanning from January 1 1980 to December 31 1989. ed can be found on virtually every version of Unix and Linux available, and as such is useful for people who have to work with multiple versions of Unix. Linux (commonly pronounced ˈlɪnəks If something goes wrong, ed is sometimes the only editor available. This is often the only time when it is used interactively.

The ed commands are often imitated in other line-based editors. For example, EDLIN in early MS-DOS versions and 32-bit versions of Windows NT has a somewhat similar syntax, and text editors in many MUDs (LPMud and descendants, for example) use ed-like syntax. Edlin is a Line editor included with MS-DOS and later Microsoft operating systems MS-DOS (short for M icro' s' oft D isk O perating S ystem is an Operating system commercialized by Microsoft. The range of Integer values that can be stored in 32 bits is 0 through 4294967295 or −2147483648 through 2147483647 using Two's complement encoding Windows NT is a family of Operating systems produced by Microsoft, the first version of which was released in July 1993 In computer gaming, a MUD ( Multi-User Dungeon, Domain or Dimension) is a multi-player computer game that combines elements of LPMud (sometimes shortened to simply " LP " is a MUD variant developed in 1989 by '''L'''ars '''P'''ensjö (hence the LP in LPMud that These editors, however, are typically more limited in function.

Contents 1 Example 2 Bill Joy, vi, and ed 3 See also 4 Footnotes 5 External links

Example

Here is an example transcript of an ed session. For clarity, commands and text typed by the user are in normal face, and output from ed is emphasized.

a
ed is the standard Unix text editor. 
  
This is line number two. 
. 
2i
  
. 
%l
ed is the standard Unix text editor. $
$
This is line number two. $
3s/two/three/
,l
ed is the standard Unix text editor. $
$
This is line number three. $
w text
65
q

The end result is a simple text file containing the following text:

ed is the standard Unix text editor. 
  
This is line number three. 

Started with an empty file, the a command appends text (all ed commands are single letters). The command put ed in insert mode, inserting the characters that follow and is terminated by a single dot on a line. The two lines that are entered before the dot end up in the file buffer. The 2i command also goes into insert mode, and will insert the entered text (a single empty line in our case) before line two. All commands may be prefixed by a line number to operate on that line.

In %l the l stands for the list command. The command is prefixed by a range, in this case % which is a shortcut for 1,$. A range is two line numbers separated by a comma ($ means the last line). In return, ed lists all lines, from first to last. These lines are ended with dollar signs, so that white space at the end of lines is clearly visible.

The error in line 3 is corrected with 3s/two/three/, a substitution command. The 3 will apply it to the correct line, following the command is the text to be replaced, and then the replacement. Listing all lines with ,l (a lone comma is also a synonym for %) the line is shown now to be correct.

w text writes the buffer to the file "text" making ed respond with 65, the number of characters written to the file. q will end an ed session.

Bill Joy, vi, and ed

In the editor wars, Emacs proponents used to say, "even Bill Joy doesn't use vi anymore. Editor war is the common name for the rivalry between users of the Vi and Emacs Text editors The rivalry has become a lasting part of Hacker culture Emacs is a class of feature-rich Text editors usually characterized by their extensibility William Nelson Joy (born Nov 8, 1954) commonly known as Bill Joy, is an American Computer scientist. "

In a 1984 interview^[1] Bill Joy explained that, at Sun, he used an early desktop publishing program, called Interleaf; when visiting labs outside Sun, he used plain old ed. Year 1984 ( MCMLXXXIV) was a Leap year starting on Sunday (link displays the 1984 Gregorian calendar) Sun Microsystems Inc ( is a multinational vendor of Computers computer components Computer software, and Information technology services Founded in 1981 Interleaf was a company that produced a technical publishing software product with the same name Although vi was almost ubiquitous, he could not count on the local version working the way he expected. However, ed was never modified, so he could count on making it work without making himself look like a fool.

See also

• Edlin, the standard MS-DOS line editor. Edlin is a Line editor included with MS-DOS and later Microsoft operating systems
• List of Unix programs
• Editor wars
• vi

Footnotes

External links

• GNU ed homepage
• ed(1): text editor – Linux man page
• GNU ed for Win32
• Unix Editors I
• Examples for ed in scripts
• ed Humor

Linux (commonly pronounced ˈlɪnəks Almost all substantial UNIX and Unix-like Operating systems have extensive documentation known as man pages (short for "manual pages"

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