[Buildroot] Qt command line issue

[Buildroot] Qt command line issue

[Karl Krach]

Hello,

I have two configuration problems:

1) After initializing Qt (new QApplication()) all output to the cmd is 
blocked (stderr, stdout, etc). This happens on the tty (serial 
connection) but not when connecting via SSH.

2) The output via SSH lacks of a "carriage return". On X11 it's working 
fine, but on the ARM evaluation board the output looks like this:
my debug output
                my debug output
                               my debug output
                                              my debug output
                                                             ...

Are these a known problems and how can I solve them?


Best Regards,

Charly

[Buildroot] Qt command line issue

[Arnout Vandecappelle]

On Friday 20 January 2012 12:32:17 Karl Krach wrote:
> 2) The output via SSH lacks of a "carriage return". On X11 it's working 
> fine, but on the ARM evaluation board the output looks like this:
> my debug output
>                 my debug output
>                                my debug output
>                                               my debug output
>                                                              ...
 
 Are you sure you get this over SSH?  This is typically what you see on a
serial terminal.  The serial terminal should be configured to expect LF
instead of CRLF.  Alternatively, if you have a shell on the other side,
you can do 'stty onlret' (or is it -onlret?) to let the tty driver insert
the CR.

 Don't know about your other issue.


 Regards,
 Arnout


-- 
Arnout Vandecappelle                               arnout at mind be
Senior Embedded Software Architect                 +32-16-286540
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[Buildroot] Qt command line issue

[Karl Krach]

On Sat, 21 Jan 2012 03:53:59 +0100, Arnout Vandecappelle wrote:
> Are you sure you get this over SSH?  This is typically what you see 
> on a
> serial terminal.  The serial terminal should be configured to expect 
> LF
> instead of CRLF.  Alternatively, if you have a shell on the other 
> side,
> you can do 'stty onlret' (or is it -onlret?) to let the tty driver 
> insert
> the CR.

You ve been right. I was just so naive to type "stty onlret" before 
starting my application. This is how it works:

     // Save terminal settings
     int m_tty_fd = 0;
     struct ::termios termdata;
     tcgetattr(m_tty_fd, &termdata);

     QApplication app( argc, argv, QApplication::GuiServer );

     // Restore terminal settings
     tcsetattr(m_tty_fd, TCSANOW, &termdata);


There is a line in the Qt sources (which I found after Frank gave me 
the tip, that the problem only appears when setting the QWS_KEYBOARD 
environment variable) which removes the "onlret flag" when isatty(0) 
returns true. Issue #1 is also solved with this lines - but I don't know 
why :)

Best regards,

Charly