Re: Display file attributes

[Douglas Handy <dhandy@xxxxxxxxx>]

> I've not bothered to look at this in probably 15 years, but doesn't
> client access support some APIs like the old emulation did?  

FWIW, client access does indeed support APIs to get the "presentation
space" of an emulated session, and IBM even has some sample programs. 
Running the Emulator HLL API (EHLLAPI) sample, it appears that I can
read any byte on the screen but only update bytes which are within
input capable fields.  Trying to place a character in a non-field area
or over a display attribute causes a return code of 5 instead of 0. 
The docs define return code 5 as:

  "The target presentation space is protected or inhibited, or
incorrect data was sent to the target presentation space (such as a
field attribute byte)."

Or at least that is the case when using the "copy string to
presentation space" function -- maybe thre is another API which would
act more like the old 5250 emulation APIs and let you modify non-input
capable bytes too.  That's how I made them visible in the old days.

Doug