Re: Porting C app from FreeBSD 4.6 to RH7.3

[Thomas Dickey]

On Thu, Feb 13, 2003 at 09:27:46AM -0500, Billy Davis wrote:
> We successfully converted our ncurses based application from FreeBSD4.6 to
> Redhat 7.3 and all seems to be running well except for two display problems,
> as follows:
> 
>     1. When we enter text into a window in the RedHat version, the text is
> properly echoed in the input field, but it is also echoed at the top left
> hand of the main screen, (ie, at line 1, column 1).  This does not seem to
> affect the data, but is distracting to the User.  This problem occurs BOTH
> when we are logged into the System console, and when we do a telnet login
> from a PC that is emulating a vt100.

I haven't seen any reports before related to this.  Normally echoing is
controlled by ncurses.  If the application works fine on FreeBSD it's
still possible that there may be some uninitialized memory location.  I'd
try running the application with valgrind, for instance.
 
>     2. When a window is defined to display a max of 12 lines at a time, but
> we have more lines to display, we use the up/down arrow keys to scroll the
> lines.  On the RedHat system, when we try to scroll rapidly, the scrolling
> seems to get jumbled, with some lines showing up twice.  Again, the data is
> not affected.  This problem ONLY occurs when we do a telnet login from a PC
> that is emulating a vt100, leading us to believe that it may be a terminfo

or network delays (man ncurses):

       ESCDELAY
            Specifies  the total time, in milliseconds, for which
            ncurses will await  a  character  sequence,  e.g.,  a
            function  key.  The default value, 1000 milliseconds,
            is enough for most uses.  However, it is made a vari-
            able to accommodate unusual applications.

            The most common instance where you may wish to change
            this value is to work with slow hosts, e.g.,  running
            on  a  network.   If  the host cannot read characters
            rapidly enough, it will have the same  effect  as  if
            the  terminal did not send characters rapidly enough.
            The library will still see a timeout.

> problem, but the only modification that we made to the vt100 terminfo entry
> was to delete two entries (rmkx=\E[?1l\E> and smkx=\E[?1h\E=), which solved
> a command mode switching problem.   If we do a page scroll up/down (via
> Fkeys), it works fine.
> 
> The ncurses version within FreeBSD is 5.1 (version patch 20001009), and the
> programs run perfectly fine with it, using the same equipment and the same
> vt100 emulator.
> 
> Has anyone else experienced (and solved) this problem?
> 
> Thanks,
> Billy Davis
> 
> 
> 
> 
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-- 
Thomas E. Dickey <address@hidden>
http://invisible-island.net
ftp://invisible-island.net