strange behaviour -- gdbtk & stdin on winxp

strange behaviour -- gdbtk & stdin on winxp

[James Lemke]

I did some searching on the archives but didn't find anything similar.
I'm using xscale-elf-insight.exe built from 6.1 sources, serially
connected to an xscale board.  I'm debugging a simple program that reads
a string via fgets((char *)input_char, MAX_INPUT_LINE, stdin).

All works as expected with xscale-elf-gdb or xscale-elf-insight -nw. 
But with the GUI, fgets() returns immediately with NULL, and errno set
to 9 (EBADF).

When built for a Linux host, xscale-elf-insight with and without -nw
work fine.

Does this problem sound familiar to anyone?
Jim.

-- 
James Lemke   jim@TheLemkes.ca   Orillia, Ontario
1992 ST1100, STOC #3750;   FWD# M:245401 H:246889
Life is what happens while you're busy making other plans. --John Lennon

Re: strange behaviour -- gdbtk & stdin on winxp

[Keith Seitz]

On Fri, 2005-04-15 at 16:36 -0400, James Lemke wrote:
> All works as expected with xscale-elf-gdb or xscale-elf-insight -nw. 
> But with the GUI, fgets() returns immediately with NULL, and errno set
> to 9 (EBADF).
> 
> When built for a Linux host, xscale-elf-insight with and without -nw
> work fine.

I am assuming that you're trying to run on windows, and your problem
doesn't surprise me in the least. Quite frankly, I don't think we ever
got windows working as well as unix hosts.

While I would guess this works for native cygwin apps, I'll bet insight
never gets stdin reopened for some "terminal", and I don't believe that
there is any special magic in gdb/insight to re-route stdin calls to the
console window (although on a remote that shouldn't be too hard). 

I suspect some hacking is in your future...

Keith

Re: strange behaviour -- gdbtk & stdin on winxp

[James Lemke]

On Fri, 2005-04-15 at 16:50, Keith Seitz wrote:
> On Fri, 2005-04-15 at 16:36 -0400, James Lemke wrote:
> > All works as expected with xscale-elf-gdb or xscale-elf-insight -nw. 
> > But with the GUI, fgets() returns immediately with NULL, and errno set
> > to 9 (EBADF).
> > 
> > When built for a Linux host, xscale-elf-insight with and without -nw
> > work fine.
> 
> I am assuming that you're trying to run on windows, and your problem
> doesn't surprise me in the least. Quite frankly, I don't think we ever
> got windows working as well as unix hosts.
> 
> While I would guess this works for native cygwin apps, I'll bet insight
> never gets stdin reopened for some "terminal", and I don't believe that
> there is any special magic in gdb/insight to re-route stdin calls to the
> console window (although on a remote that shouldn't be too hard). 
> 
> I suspect some hacking is in your future...

Yup, sounds like it.  Thanks for the thoughts.
Jim.

-- 
James Lemke   jim@TheLemkes.ca   Orillia, Ontario
1992 ST1100, STOC #3750;   FWD# M:245401 H:246889
Life is what happens while you're busy making other plans. --John Lennon

Re: strange behaviour -- gdbtk & stdin on winxp

[James Lemke]

On Fri, 2005-04-15 at 16:50, Keith Seitz wrote:
> On Fri, 2005-04-15 at 16:36 -0400, James Lemke wrote:
> > All works as expected with xscale-elf-gdb or xscale-elf-insight -nw. 
> > But with the GUI, fgets() returns immediately with NULL, and errno set
> > to 9 (EBADF).
> > 
> > When built for a Linux host, xscale-elf-insight with and without -nw
> > work fine.
> 
> I am assuming that you're trying to run on windows, and your problem
> doesn't surprise me in the least. Quite frankly, I don't think we ever
> got windows working as well as unix hosts.
> 
> While I would guess this works for native cygwin apps, I'll bet insight
> never gets stdin reopened for some "terminal", and I don't believe that
> there is any special magic in gdb/insight to re-route stdin calls to the
> console window (although on a remote that shouldn't be too hard). 
> 
> I suspect some hacking is in your future...

FYI and to archive for future searchers...

If I use an rxvt window (rxvt -e /bin/bash) vs the default Cygwin
window, insight reads from stdin fine just as it does on Linux.

Cheers,
Jim.

-- 
James Lemke   jim@TheLemkes.ca   Orillia, Ontario
1992 ST1100, STOC #3750;   FWD# M:245401 H:246889
Life is what happens while you're busy making other plans. --John Lennon

RE: strange behaviour -- gdbtk & stdin on winxp

[Dave Korn]

----Original Message----
>From: James Lemke
>Sent: 18 April 2005 15:55

> On Fri, 2005-04-15 at 16:50, Keith Seitz wrote:
>> On Fri, 2005-04-15 at 16:36 -0400, James Lemke wrote:
>>> All works as expected with xscale-elf-gdb or xscale-elf-insight -nw.
>>> But with the GUI, fgets() returns immediately with NULL, and errno set
>>> to 9 (EBADF). 
>>> 
>>> When built for a Linux host, xscale-elf-insight with and without -nw
>>> work fine.
>> 
>> I am assuming that you're trying to run on windows, and your problem
>> doesn't surprise me in the least. Quite frankly, I don't think we ever
>> got windows working as well as unix hosts.
>> 
>> While I would guess this works for native cygwin apps, I'll bet insight
>> never gets stdin reopened for some "terminal", and I don't believe that
>> there is any special magic in gdb/insight to re-route stdin calls to the
>> console window (although on a remote that shouldn't be too hard).
>> 
>> I suspect some hacking is in your future...
> 
> FYI and to archive for future searchers...
> 
> If I use an rxvt window (rxvt -e /bin/bash) vs the default Cygwin
> window, insight reads from stdin fine just as it does on Linux.
> 
> Cheers,
> Jim.


  Jim, do you have 'tty' set in your $CYGWIN environment variable?  I don't
know if it'll help or not, but it affects tty-handling in the cygwin lib:

http://cygwin.com/cygwin-ug-net/using-cygwinenv.html

"(no)tty - if set, Cygwin enables extra support (i.e., termios) for
UNIX-like ttys. It is not compatible with some Windows programs. Defaults to
not set, in which case the tty is opened in text mode. Note that this has
been changed such that ^D works as expected instead of ^Z, and is settable
via stty. This option must be specified before starting a Cygwin shell and
it cannot be changed in the shell."

  It might or might not help to experiment with it.

    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....

RE: strange behaviour -- gdbtk & stdin on winxp

[James Lemke]

>   Jim, do you have 'tty' set in your $CYGWIN environment variable?  I don't
> know if it'll help or not, but it affects tty-handling in the cygwin lib:
> 
> http://cygwin.com/cygwin-ug-net/using-cygwinenv.html
> 
> "(no)tty - if set, Cygwin enables extra support (i.e., termios) for
> UNIX-like ttys. It is not compatible with some Windows programs. Defaults to
> not set, in which case the tty is opened in text mode. Note that this has
> been changed such that ^D works as expected instead of ^Z, and is settable
> via stty. This option must be specified before starting a Cygwin shell and
> it cannot be changed in the shell."
> 
>   It might or might not help to experiment with it.

Thanks for the idea Dave.  Unfortunately it didn't help.
I tried adding the following to c:\autoexec.bat:
set CYGWIN=tty

and the following to ~/.bash_profile:
export CYGWIN=tty

-- 
James Lemke   jim@TheLemkes.ca   Orillia, Ontario
1992 ST1100, STOC #3750;   FWD# M:245401 H:246889
Life is what happens while you're busy making other plans. --John Lennon