Target Output Streaming in MI

Target Output Streaming in MI

[chanskw]

Hi,

As we are doing more investigation with MI, we having another question
regarding output streaming in MI.  As described in GDB manual:

`"@" STRING-OUTPUT'
     The target output stream contains any textual output from the
     running target.

Some of the examples in the manual show that program's output should be
prefixed with '@'.  However, we have never seen program output prefixed
with '@'.  After doing more experiments and looking into GDB source code,
we found that program output will only be prefixed with '@' during remote
debugging.  Is this really the case?

Thank you.

Regards,
Samantha Chan

Re: Target Output Streaming in MI

[Daniel Jacobowitz]

On Thu, May 02, 2002 at 05:10:56PM -0400, chanskw@ca.ibm.com wrote:
> Hi,
> 
> As we are doing more investigation with MI, we having another question
> regarding output streaming in MI.  As described in GDB manual:
> 
> `"@" STRING-OUTPUT'
>      The target output stream contains any textual output from the
>      running target.
> 
> Some of the examples in the manual show that program's output should be
> prefixed with '@'.  However, we have never seen program output prefixed
> with '@'.  After doing more experiments and looking into GDB source code,
> we found that program output will only be prefixed with '@' during remote
> debugging.  Is this really the case?

Essentially, yes.  There's a known failure in mi-console.exp
corresponding to this; it requires that GDB manage pseudoterminals for
the inferior process, and we don't do that (nor have we really decided
that it is a good idea; I at least have doubts...).


IMVHO, the best thing to do for native would be to have MI traffic on a
separate file descriptor than the inferior's stdin/out/err.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: Target Output Streaming in MI

[Brian Thomson]

Daniel Jacobowitz wrote:

> IMVHO, the best thing to do for native would be to have MI traffic on a
> separate file descriptor than the inferior's stdin/out/err.
>
Could the external MI client pass the fd # on the command line?
Are there host platforms where an fd can't be externalized like that?

Brian Thomson
IBM