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Xedit

 

Xedit

XEDIT is a visual editor for VM/CMS using block mode IBM 3270 terminals.   (Line-mode terminals are also supported.) [1] [2] XEDIT is much more line-oriented than modern PC and Unix editors. For example, XEDIT 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, a program function key (PFK), or a program access key (PAK)], XEDIT is less interactive than many PC and Unix editors. For example, continuous spell-checking as the user types is problematic.

Contents

  • Typical screen layout 1
  • Macro language 2
  • History 3
  • PC and Unix adaptations 4
  • References 5
  • External links 6

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 filename
    • SCRIPT   is the filetype
    • A1   is the filemode (default, indicating which disk the file is on)
    • V   is the record format (RECFM) which can be Fixed or Variable
    • 132   is the length of the records (for V, the maximum length)
    • Trunc=132   indicates changes beyond 132 columns will be ignored
    • Size=10   denotes total number of lines in file
    • Line=10   denotes the current line
    • Col=1   denotes the current column
    • Alt=10   indicates that ten changes have been made while XEDITing
  • The equal signs at the beginning of the lines provide space for line numbers if desired, and a place to enter XEDIT prefix commands that may operate on blocks of lines.
  • The next-to-bottom line is a command line for entering XEDIT or system (CP/CMS) commands or macros.
  • There is no mouse pointer because most IBM 3270 terminals did not have mice.[3]
  • Most IBM 3270 terminals had 12 or 24 program function keys (PFKs) (and also two or three program assist keys), to which XEDIT commands or macros could be assigned.
  • XEDIT commands can be used to change the screen appearance. Some examples include:
    • moving (or eliminating) the position of the command line
    • moving (or eliminating) the TABS marker line
    • moving (or eliminating) the position of the PREFIX lines
    • moving (or eliminating) the current line indicator
    • whether or not TAB characters are to be expanded
    • define which lines to be displayed by scope (SELECT)
    • showing the data on a display screen or typewriter mode
    • specifying text(s) to be displayed on the screen (RESERVED)
    • changing the prefix line from equal signs (=====) to line numbers (nnnnn)
    • eliminating the TOFEOF lines (* * * Top of File * * * --and-- * * * End of File * * *)
    • displaying (or eliminating) SHADOW lines (indications that lines are not being displayed)
    • displaying (or eliminating) the SCALE lines (a scale or ruler to assist editing)
    • changing the background and foreground colors used for the different portions of the screen
    • defining what lines are to be displayed (RANGE)
    • define what columns are to be displayed (and also, if in hexadecimal, text, or both)
    • define multiple XEDIT screens [sizes, location (over/under, side by side, combinations)]

Macro language

XEDIT macros (scripts) can be written in REXX, EXEC2, or EXEC.

KEDIT 5 for DOS and OS/2 supports an external REXX interpreter (native OS/2 REXX or Quercus REXX, for DOS only Quercus REXX replacing the older Mansfield REXX) and its own rather limited KEXX subset. KEDITW 1.6.1 for Windows supports only its own internal KEXX 5.62 version of the REXX language.[4] Macros can be arranged in the .kml file format.

XEDIT exposes the majority of its internal state to REXX, allowing macros to easily read and set internal variables that control its operation.

History

XEDIT was written by IBM employee Xavier de Lamberterie and was first released in 1980.[5] Its predecessor was EDIT SP (SP is an acronym for System Product used by IBM). Other key influences were EDIT, the older editor for CMS, and EDGAR, an IBM Program Product editor for CMS. XEDIT supported many of the EDGAR commands, SOS (Screen Output Simulation) being a major one. XEDIT also supported EXEC2, the predecessor of REXX.

In December 2012 Mansfield Software released 1.6.1 to provide compatibility with Windows 8 and extended support to at least June 2015. These 32bit versions work also in the 64bit versions of Windows 7 and Vista, but do not directly support Unicode.[4][6]

PC and Unix adaptations

Keditw 1.6.1 screenshot

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.[7] The last version for DOS and OS/2 was KEDIT 5.0p4. KeditW (for Windows) is at version 1.6.1 dated December 2012,[6] previously 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.[7][8]
    KEDIT 1.6 supports syntax highlighting for various languages including C♯, COBOL, FORTRAN, HTML, Java, Pascal, and xBase defined in the .kld file format.[9]
  • 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).[10][11]
  • 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. ^
  2. ^
  3. ^
  4. ^ a b
  5. ^
  6. ^ a b
  7. ^ a b
  8. ^
  9. ^
  10. ^
  11. ^

External links

  • KEDIT, a Mansfield Software Group product, for DOS, OS/2, and Windows.
  • KEDIT/KEXX summary by Rex Swain
  • KEXX Macros at the Wayback Machine (archived May 22, 2013) macro collection
  • 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)
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