vc++6.0: capture cerr

[Mike - EMAIL IGNORED]

I have a VC++6.0 program than calls library functions
that write to cerr. I would like to capture this output
in the calling program. Would you please let me know
how I could to this? If I should ask on another group,
please let me know.
Thanks in advance,
Mike.

[WW]

Re: vc++6.0: capture cerr

Mike - EMAIL IGNORED wrote:[color=blue]
> I have a VC++6.0 program than calls library functions
> that write to cerr. I would like to capture this output
> in the calling program. Would you please let me know
> how I could to this? If I should ask on another group,
> please let me know.[/color]

You need to. A Microsoft one. Or a POSIX one - if MS really does implement
POSIX as they say the do. The Standard C++ has no support for this. I mean
you can redirect cerr to file (well, not on all MS OSes) and then read that
file, but I think you would rather want something like a pipe. And pipes
are not in standard C++.

--
WW aka Attila

[Ryan Winter]

Re: vc++6.0: capture cerr

Mike - EMAIL IGNORED wrote:[color=blue]
> I have a VC++6.0 program than calls library functions
> that write to cerr. I would like to capture this output
> in the calling program. Would you please let me know
> how I could to this? If I should ask on another group,
> please let me know.[/color]

Take a look at this page. It describes (in a round about way) how to
reassign standard streams to whever you would like.

http://www.noasia.net/taowen/classic/004/2001_3.htm

[Dietmar Kuehl]

Re: vc++6.0: capture cerr

"WW" <wolof@freemail .hu> wrote:[color=blue]
> Mike - EMAIL IGNORED wrote:[color=green]
> > I have a VC++6.0 program than calls library functions
> > that write to cerr. I would like to capture this output
> > in the calling program. Would you please let me know
> > how I could to this? If I should ask on another group,
> > please let me know.[/color]
>
> You need to. A Microsoft one. Or a POSIX one - if MS really does implement
> POSIX as they say the do. The Standard C++ has no support for this. I mean
> you can redirect cerr to file (well, not on all MS OSes) and then read that
> file, but I think you would rather want something like a pipe. And pipes
> are not in standard C++.[/color]

If the library really writes to 'std::cerr' rather than writing to the
standard error stream using eg. 'fprintf(stderr , ...)' or 'write(2, ...)',
there is a perfectly portable C++ solution to the problem: it is possible
install a new stream buffer into 'std::cerr' to which all characters written
to 'std::cerr' are sent:

std::ostringstr eam serr;
std::streambuf* cerr_sbuf = std::cerr.rdbuf ();
std::cerr.rdbuf (serr.rdbuf());
// now everything written to 'std::cerr' is captured by serr
cerr.rdbuf(cerr _sbuf); // restore original stream buffer to avoid
// references to deleted objects
--
<mailto:dietmar _kuehl@yahoo.co m> <http://www.dietmar-kuehl.de/>
Phaidros eaSE - Easy Software Engineering: <http://www.phaidros.co m/>

[Attila Feher]

Re: vc++6.0: capture cerr

Dietmar Kuehl wrote:[color=blue]
> "WW" <wolof@freemail .hu> wrote:[color=green]
>> Mike - EMAIL IGNORED wrote:[color=darkred]
>>> I have a VC++6.0 program than calls library functions
>>> that write to cerr. I would like to capture this output
>>> in the calling program. Would you please let me know
>>> how I could to this? If I should ask on another group,
>>> please let me know.[/color]
>>
>> You need to. A Microsoft one. Or a POSIX one - if MS really does
>> implement POSIX as they say the do. The Standard C++ has no support
>> for this. I mean you can redirect cerr to file (well, not on all MS
>> OSes) and then read that file, but I think you would rather want
>> something like a pipe. And pipes are not in standard C++.[/color]
>
> If the library really writes to 'std::cerr' rather than writing to the
> standard error stream using eg. 'fprintf(stderr , ...)' or 'write(2,
> ...)', there is a perfectly portable C++ solution to the problem: it
> is possible install a new stream buffer into 'std::cerr' to which all
> characters written to 'std::cerr' are sent:
>
> std::ostringstr eam serr;
> std::streambuf* cerr_sbuf = std::cerr.rdbuf ();
> std::cerr.rdbuf (serr.rdbuf());
> // now everything written to 'std::cerr' is captured by serr
> cerr.rdbuf(cerr _sbuf); // restore original stream buffer to avoid
> // references to deleted objects[/color]

"I would like to capture this output in the calling program."

Do you know any standard IPC mechanism in C++? Just because you say that it
can be done using standard C++...

--
Attila aka WW

[Buster]

Re: vc++6.0: capture cerr


"Attila Feher" <attila.feher@l mf.ericsson.se> wrote[color=blue]
> Dietmar Kuehl wrote:[color=green]
> > "WW" <wolof@freemail .hu> wrote:[color=darkred]
> >> Mike - EMAIL IGNORED wrote:
> >>> I have a VC++6.0 program than calls library functions
> >>> that write to cerr. I would like to capture this output
> >>> in the calling program. Would you please let me know
> >>> how I could to this? If I should ask on another group,
> >>> please let me know.[/color][/color][/color]

[...]
[color=blue]
> "I would like to capture this output in the calling program."
>
> Do you know any standard IPC mechanism in C++? Just because you say that it
> can be done using standard C++...[/color]

Read it again. The calling program "calls library functions";
there is no mention, explicit or otherwise, of multiple processes.

Regards,
Buster.

[WW]

Re: vc++6.0: capture cerr

Buster wrote:
[SNIP][color=blue]
> Read it again. The calling program "calls library functions";
> there is no mention, explicit or otherwise, of multiple processes.[/color]

You are right. My English is even worse than I thought. Thanx for the
clarification.

--
WW aka Attila