View source for Edlin

{{Short description|Line-oriented text editor}}
{{other uses}}
{{Infobox software
| name                   = Edlin
| author                 = [[Tim Paterson]]
| developer              = [[Microsoft]], [[IBM]], Gregory Pietsch
| released               = {{Start date and age|1980}}
| programming language   = [[MS-DOS]]: [[x86 assembly language]]
| operating system       = [[86-DOS]], [[IBM PC DOS]], [[MS-DOS]], [[FreeDOS]], [[OS/2]], [[eComStation]], [[ArcaOS]], [[Microsoft Windows|Windows]]
| replaced_by            = [[MS-DOS Editor]]
| genre                  = [[Line editor]]
| license                = MS-DOS: [[MIT License|MIT]]<br />FreeDOS, ReactOS: [[GNU General Public License|GPL]]<br />86-DOS, PC DOS, OS/2, Windows: [[Proprietary software|Proprietary]] [[commercial software]]
| website                = [https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/edlin_line.mspx?mfr=true Edlin]
}}

'''Edlin''' is a [[line editor]], and the only [[text editor]] provided with early versions of [[IBM PC DOS]],<ref>{{cite web|url=http://www.bitsavers.org/pdf/ibm/pc/dos/6172220_DOS_1.0_Jan82.pdf|title=Disk Operating System|date=January 1982|website=Bitsavers.org|access-date=24 January 2022}}</ref> [[MS-DOS]] and [[OS/2]].<ref>{{cite web| url = http://www.os2museum.com/wp/os2-history/os2-1-0/| title = OS/2 1.0 |website=Os2museum.com}}</ref> Although superseded in MS-DOS 5.0 and later by the full-screen [[MS-DOS Editor]], and by [[Microsoft Notepad|Notepad]] in [[Microsoft Windows]], it continued to be included in the 32-bit versions of Microsoft operating systems up to Windows Server 2008 and Windows 10.

==History==
[[File:IBM PC DOS 1.0 screenshot.png|thumb|300px|<code>EDLIN.COM</code> (among several other commands) in [[IBM PC DOS]] 1.0]]
[[File:ATOK 8 for PC-98 screenshot.png|thumb|300px|Using EDLIN for typing Japanese with the [[ATOK]] 8 input method editor, running on [[MS-DOS]] 3.3C for the [[PC-9800 series]]]]
Edlin was created by [[Tim Paterson]] in two weeks in 1980, for [[Seattle Computer Products]]'s [[86-DOS]] (QDOS)<ref>{{cite web| url-status=dead|archive-url=https://web.archive.org/web/20190518224631/http://www.patersontech.com/dos/byte%E2%80%93history.aspx| archive-date=2019-05-18 | url = http://www.patersontech.com/dos/byte%E2%80%93history.aspx| title = A Short History of MS-DOS|website=Patersontech.com}}</ref> based on the [[CP/M]] context editor ''ED'',<ref>{{Cite web|url=http://www.shaels.net/index.php/cpm80-22-documents/using-cpm/8-ed-utility|archiveurl=https://web.archive.org/web/20130620002545/http://www.shaels.net/index.php/cpm80-22-documents/using-cpm/8-ed-utility|url-status=dead|title=ED Utility|archive-date=20 June 2013|website=Shaels.net|access-date=24 January 2022}}</ref><ref>{{Cite web|url=https://archive.org/details/bitsavers_digitalResrsManual1978_1058478|title=ED: A Context Editor for The CP/M Disk System|website=archive.org|date=1978 |access-date=8 May 2023}}</ref> itself distantly inspired by the [[DEC PDP-10]] [[TOPS-10]] EDIT text editor.

Microsoft acquired 86-DOS and, after some further development, sold it as MS-DOS, so Edlin was included in v1.0–v5.0 of MS-DOS. From MS-DOS 6 onwards, the only editor included was the new full-screen [[MS-DOS Editor]]. 

[[Windows 95]], [[Windows 98|98]] and [[Windows ME|ME]] ran on top of an embedded version of DOS, which reports itself as [[MS-DOS 7]]. As a successor to MS-DOS 6, this did not include Edlin. 

However, Edlin is included in the 32-bit versions of [[Windows NT]]<ref>[http://support.microsoft.com/kb/101929 16-Bit Applications Included with Windows NT], Microsoft.com</ref> and its derivatives—up to and including [[Windows 10]]—because the [[Virtual DOS machine|NTVDM]]'s DOS support in those operating systems is based on MS-DOS version 5.0. However, unlike most other external DOS commands, it has not been transformed into a native [[Windows API|Win32]] program. It also does not support [[long filename]]s, which were not added to MS-DOS and Windows until long after Edlin was written.

The [[FreeDOS]] version was developed by Gregory Pietsch.<ref>{{cite web| url = http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/edlin.html| website=Ibiblio.org|title=FreeDOS Package -- edlin (FreeDOS Base)}}</ref>

==Usage==
There are only a few commands. The short list can be found by entering a ? at the edlin prompt.

When a file is open, typing L lists the contents (e.g., <code>1,6L</code> lists lines 1 through 6). Each line is displayed with a line number in front of it.

 *1,6L
        1: Edlin: The only text editor in early versions of DOS.
        2:
        3: Back in the day, I remember seeing web pages
        4: branded with a logo at the bottom:
        5: "This page created in edlin."
        6: The things that some people put themselves through. ;-)
 *

The currently selected line has an *.  To replace the contents of any line, the line number is entered and any text entered replaces the original.  While editing a line pressing Ctrl-C cancels any changes. The * marker remains on that line.

Entering I (optionally preceded with a line number) inserts one or more lines before the * line or the line given.  When finished entering lines, Ctrl-C returns to the edlin command prompt.

 *6I
        6:*(...or similar)
        7:*^C 
 &nbsp;
 *7D
 *L
        1: Edlin: The only text editor in early versions of DOS.
        2:
        3: Back in the day, I remember seeing web pages
        4: branded with a logo at the bottom:
        5: "This page created in edlin."
        6: (...or similar)
 *

:'''i''' - Inserts lines of text.
:'''D''' - deletes the specified line, again optionally starting with the number of a line, or a range of lines.  E.g.: <code>2,4d</code> deletes lines 2 through 4.  In the above example, line 7 was deleted.

:'''R''' - is used to replace all occurrences of a piece of text in a given range of lines, for example, to replace a spelling error.  Including the ? prompts for each change.  E.g.: To replace 'prit' with 'print' and to prompt for each change: <code>?rprit^Zprint</code> (the ^Z represents pressing CTRL-Z).  It is case-sensitive.

:'''S''' - searches for given text.  It is used in the same way as replace, but without the replacement text.  A search for 'apple' in the first 20 lines of a file is typed <code>1,20?sapple</code> (no space, unless that is part of the search) followed by a press of enter.  For each match, it asks if it is the correct one, and accepts n or y (or Enter).

:'''P''' - displays a listing of a range of lines. If no range is specified, P displays the complete file from the * to the end. This is different from L in that P changes the current line to be the last line in the range.

:'''T''' - transfers another file into the one being edited, with this syntax: [line to insert at]t[full path to file].

:'''W''' - (write) saves the file.

:'''E''' - saves the file and quits edlin.

:'''Q''' - quits edlin without saving.

===Scripts===
Edlin may be used as a non-interactive file editor in scripts by [[Redirection (computing)|redirecting]] a series of edlin commands.

 edlin < script

===FreeDOS Edlin===
A [[GNU General Public License|GPL]]-licensed [[clone (computer science)|clone]] of Edlin that includes long filename support is available for download as part of the [[FreeDOS]] project. This runs on operating systems such as [[Linux]] or [[Unix]] as well as MS-DOS.<ref>{{cite web| url = https://sourceforge.net/projects/freedos-edlin| title = FreeDOS Edlin|website=Sourceforge.net| date = 3 March 2023}}</ref>

==See also==
*[[List of DOS commands]]
*[[ed (text editor)|ed]] and [[ex (text editor)|ex]], similar [[Unix]] line editors. 
*[[86-DOS]]

==References==
{{Reflist}}

==Further reading==
* {{Cite book|title=Microsoft Operating System/2 User's Reference|date=1987|publisher=[[Microsoft]]|url=http://www.os2museum.com/wp/wp-content/uploads/2011/12/1987-Oct-OS2-1.0-Users_Reference.pdf}}

==External links==
{{Wikibooks|Guide to Windows Commands}}
*[https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-xp/bb490632(v=technet.10) Edlin | Microsoft Docs]
*[http://www.computerhope.com/edlin.htm MS-DOS edlin command help]
*[https://github.com/microsoft/MS-DOS/blob/master/v2.0/source/EDLIN.ASM Open source EDLIN implementation that comes with MS-DOS v2.0]

{{Windows commands}}

[[Category:1980 software]]
[[Category:Console applications]]
[[Category:DOS text editors]]
[[Category:Line editor]]
[[Category:OS/2 commands]]
[[Category:Microsoft free software]]
[[Category:Windows components]]
[[Category:Windows text editors]]