XEDIT is a visual editor for VM/CMS using block mode IBM 3270 terminals. ^{[1] [2]} It is much more line-oriented than modern PC and Unix editors. For example, it supports automatic line numbers, and many of the commands operate on blocks of lines. One of the features is a command line which allows the user to type arbitrary editor commands. Because IBM 3270 terminals do not transmit data to the computer until certain special keys are pressed (such as enter and function keys) XEDIT is less interactive than many PC and UNIX editors. For example, continuous spell-checking as the user types is impossible.

Typical screen layout

 MOHICANS SCRIPT A1 V 132 Trunc=132 Size=10 Line=10 Col=1 Alt=10
XEDIT:
===== Last of the Mohicans
===== .sp
===== It was a feature peculiar to the colonial wars of North America,
===== that the toils and dangers of the wilderness were to be encountered
===== before the adverse hosts could meet.
===== A wide and apparently an impervious boundary of forests severed
===== the possessions of the hostile provinces of France and England.
===== The hardy colonist, and the trained European who fought at his
===== side, frequently expended months in struggling against the rapids
===== of the streams, or in effecting the rugged passes of the mountains
|...+....1....+....2....+....3....+....4....+....5....+....6....+....7...
===== * * * End of File * * *
====>
                                                         X E D I T 1 File

Notable features of the screen layout:

• The top line provides details about line format where MOHICANS is the file name, SCRIPT is the type, mode is A1 (default, indicating which disk the file is on), V 132 specifies record format (fixed or variable length records/lines in the file) and maximum record length, Size=10 denotes total number of lines in file, Line=10 Col=1 denotes current line & current column.
• The equal signs at the beginning of the lines provide space for line numbers if desired, and a place to enter commands that operate on blocks of lines
• The next-to-bottom line is a command line for typing edit commands.
• There is no mouse pointer because IBM 3270 terminals did not have mice.
• IBM 3270 terminals did have 12 function keys, to which XEDIT macros could be assigned.
• XEDIT commands can be used to change the screen appearance. Examples include moving the position of the command line, moving or eliminating the tabs marker line, changing the prefix line from equal signs to line numbers, changing the background and foreground colors used for the different portions of the screen.

Macro language

The XEDIT macro (script) language is REXX.

History

XEDIT written by Xavier de Lamberterie was first released in 1980.^[3] Its predecessor was EDIT SP (SP is an acronym for System Product used by IBM ). XEDIT also supported EXEC2, the predecessor of REXX.

It is one of the text editors held in almost religious awe by their users; see also Emacs and vi.

PC and Unix adaptations

When PCs and Unix computers began to supplant IBM 3270 terminals, some users wanted text editors that resembled the XEDIT they were accustomed to. To fill this need, several developers provided similar programs:

• KEDIT by Mansfield Software Group, Inc., was the first XEDIT clone. Although originally released in 1983, the first major release was version 3.53 for DOS, released in 1985. The last version for DOS and OS/2 was KEDIT 5.0p4. KeditW (for Windows) is at version 1.6 dated December 2007 (the latest previous release being 1.5 service level 3 dated January 1998). Kedit supports a built-in REXX-subset called KEXX. Mansfield Software created the first non-IBM implementation of REXX (Personal REXX) in 1985.^[4][5]
• SEDIT (first released in 1989) is another implementation on both Windows and Unix, which supports a variant of REXX language called S/REXX (announced in 1994).^[6][7]
• The Hessling Editor THE, written with compatibility for both KEDIT and XEDIT in mind, uses Regina, an open source version of REXX. It was begun in 1990, first released in August 1992. THE can also be built with any of several implementations of REXX, including uni-REXX.

References

1. ↑ XEDIT Commands and Macros Reference. (1st ed. Sept. 2004, pub. no. SC24-6131-00). International Business Machines
2. ↑ XEDIT User's Guide. (2d ed., Dec. 2005, pub. no. SC24-6132-01). International Business Machines
3. ↑ Melinda Varian, "VM and the VM Community: Past, Present, and Future", April, 1991, p92.
4. ↑
5. ↑
6. ↑
7. ↑

External links

• KEDIT, a Mansfield Software Group product, for DOS, OS/2, and Windows.
• KEDIT/KEXX summary by Rex Swain
• KEX macro collection includes x-wiki.kex
• PcXedit, a freeware program for Windows.
• SEDIT and S/REXX for UNIX and Windows product description
• THE, The Hessling Editor, open source using Regina as its macro language
• uni-XEDIT for UNIX product description (2003)

de:XEDIT