XEDIT is a visual editor for VM/CMS using block modeIBM 3270terminals. 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. A pair of features allows selective line and column editing. The ALL command, for example, hides all lines not matching the described pattern, and the COL command allows hiding those columns not specified. Hence changing, for example, the word NO as it appears only in columns 24 thru 28, to YES, and only on lines with the word FLEXIBLE, is doable. Another feature 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, a program function key, or a program [access key, XEDIT is less interactive than many PC and Unix editors. For example, continuous spell-checking as the user types is problematic.
*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 line beginning |...+ is a ruler that e.g. might show tabulator positions.
The following line marks end-of-file, appearing in XEDIT as if it followed the last actual line of the file.
The next-to-bottom line showing => is a command line for entering XEDIT or system commands or macros.
There is no mouse pointer because most IBM 3270 terminals did not have mice.
Most IBM 3270 terminals had 12 or 24 program function keys , to which XEDIT commands or macros could be assigned.
XEDIT commands can be used to change the screen appearance. Some examples include:
*Moving the position of the command line
*Moving the position of the TABS marker line
*Moving the position of the PREFIX lines
*Changing the prefix line from equal signs to line numbers
*Defining whether or not TAB characters are to be expanded
*Defining which lines are to be displayed by scope
*Showing the data on a display screen or in typewriter mode
*Specifying text line to be displayed on the screen
XEDIT macros can be written in Rexx, EXEC 2, or EXEC. XEDIT exposes the majority of its internal state to the macro environment, allowing macros to easily read and set internal variables that control its operation.
KEXX
KEDIT 5 for DOS and OS/2 supports an external Rexx interpreter 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. Macros can be arranged in the .kml file format.
History
XEDIT was written by IBM employee Xavier de Lamberterie and was first released in 1980. Its predecessor was EDIT SP. 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 being a major one. XEDIT also supported EXEC 2, the predecessor of Rexx.
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
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. By 1990, KEDIT 4.0 had a version supporting OS/2, and included the ALL command. The last version for DOS and OS/2 was KEDIT 5.0p4. KeditW is at version 1.6.1 dated December 2012. Some earlier Windows versions were:
KEDIT 1.6 supports syntax highlighting for various languages including C#, COBOL, FORTRAN, HTML, Java, Pascal, and xBase defined in the .kld file format. KEDIT supports a built-in Rexx-subset called KEXX. Mansfield Software created the first non-IBM implementation of Rexx in 1985. In December 2012 Mansfield Software released 1.6.1 to provide compatibility with Windows 8 and extended support to at least June. These 32bit versions work also in the 64bit versions of Windows 7 and Vista, but do not directly support Unicode. As of May 2018, Kedit supports Windows 10 too. Mansfield promised website support until at least the end of 2018 and email support until at least June 2019.
SEDIT
SEDIT is another implementation on both Windows and Unix, which supports a variant of Rexx language called S/REXX.
THE (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.
