KEDIT Hints and Tips: Retrieving and Updating the Contents of the Focus Line from within a Macro

EXTRACT /CURLINE/

If you write KEDIT macros then there will likely come a time when you will want to retrieve the contents of the focus line. You might want to examine the line to see if it begins with some special character or contains a particular character string. EXTRACT /CURLINE/ lets you do this.

A note here about terminology:

The focus line is the line of the file relative to which KEDIT commands operate. When the cursor is in the file area, the cursor line is the focus line. When the cursor is on the command line, the current line is the focus line. In textmode KEDIT the current line is, by default, displayed in the middle of the file window in a different color to distinguish it from the other lines of the file that are visible in the text area. In KEDIT for Windows the current line is delimited by thin horizontal lines above and below it when the cursor is on the command line. When the cursor is in the text area these lines disappear to indicate that the focus line is now the cursor line.

For historical reasons, and to maintain compatibility with macros written for IBM's XEDIT editor, the command used to obtain the contents of the focus line is EXTRACT /CURLINE/, rather than EXTRACT /FOCUSLINE/.

Say you have a text file that looks like this, where line 4 is the focus line:

Your macro could use the EXTRACT /CURLINE/ command like this:

* Retrieve information regarding the focus line
"extract /curline/"

if pos("CANADA", upper(curline.3)) > 0 then say "It's from Canada"
   else say "It's from somewhere other than Canada"

EXTRACT /CURLINE/ sets several variables but the one you are interested in is CURLINE.3 which is the contents of the focus line. In this example, CURLINE.3 is set to "Victoria, BC Canada".

As noted above, EXTRACT /CURLINE/ returns more information than just the contents of the focus line. This EXTRACT command sets CURLINE.1 through CURLINE.6. This is really more information than is needed for this example. A slightly more efficient method of retrieving just the contents of the focus line is to use an implied extract function. For example:

FocusLine = curline.3()

if pos("CANADA", upper(FocusLine)) > 0 then say "It's from Canada"
   else say "It's from somewhere other than Canada"

Note that there is no explicit EXTRACT command used here and rather than referencing the variable CURLINE.3, the curline.3() implied extract function is called. This function returns only the contents of the focus line. In fact, in this example the contents of the focus line are extracted only once so the above code can be written in this more compact form:

if pos("CANADA", upper(curline.3())) > 0 then say "It's from Canada"
   else say "It's from somewhere other than Canada"

Retrieving a copy of the focus line is an important thing to be able to do in a macro. Being able to change the contents of the focus line is just as important though.

The REPLACE Command

The REPLACE command takes whatever text is specified after it and replaces the contents of the focus line with this text. For example, if you were to enter this on the KEDIT command line:

replace This is a new focus line string

then the contents of the focus line would be replaced with "This is a new focus line string" beginning in column 1. The single space between the command REPLACE and the beginning of the text acts as a separator so this is not part of the text that replaces the focus line. Any further leading spaces on the text though become part of the updated focus line. Here's an example of a macro that conditionally modifies the contents of the focus line:

* Get a copy of the focus line
FocusLine = curline.3()

* Update the focus line based on the first blank-delimited string in
* the line
if word(FocusLine, 1) = "NX" then "replace This was an NX entry"
   else "replace This was a non-NX entry"