Re: Help wanted with bkgd() rookie mistake

[Bill Gray]

Hi Branden,

On 1/5/25 11:23, G. Branden Robinson wrote:
> Hi folks,
>
> I come once again to confess my confusion with basic curses operations.
>
> Please find attached two C programs; I call them "bkgd" and "bkgrnd",
> because they correspond to curses functions of the same name.
>
> bkgrnd, the wide-character program, works fine.
>
> bkgd, which you'd think would be simpler, doesn't.
>
> In both, I expect the background character to be set to an underlined @
> sign.

   I see the background as underlined @ signs with both programs.  I'm 
using (default,  system-installed,  now getting to be elderly) ncurses 
6.2.20200212.  So perhaps a behavior change between then and now?

   However,  both PDCurses and PDCursesMod show @ with no underscore. 
I agree that this seems wrong.

   (BTW,  why do you have tests for NCURSES_VERSION and NCURSES_OPAQUE? 
 It looks to me as if you aren't using anything ncurses-specific and 
that your code doesn't rely on opaqueness.  FWIW,  PDCursesMod has 
opaque window and screen structures;  PDCurses doesn't.)

-- Bill

> But only bkgrnd() is behaving this way.  It seems that logically or-ing
> the character literal '@' with A_UNDERLINE is somehow wiping out the
> character part.  Except it's not, because if I printf that expression as
> a decimal integer, I can see that they indeed compose.
>
> bkgd() seems to be discarding my character code.  What am I not
> understanding?
>
> Regards,
> Branden