RE: Problems with stringstream

RE: Problems with stringstream

[Moore, Mathew L]

I wonder if this problem can be narrowed down?  Does it take this exact code
listing to reproduce the problem?  Can you just print out a string?

	string mystr("test");
	cout << mystr;

If your debugger produces the correct result, it would at least seem that
the stringstream portion is working correctly.  I wonder if your stdout was
remapped somewhere (is that possible?).

--Matt



> -----Original Message-----
> From: Jessee, Mark [mailto:Mark.Jessee@gdcanada.com]
> Sent: Friday, October 25, 2002 12:30
> To: 'gcc-help@gcc.gnu.org'
> Cc: 'John Love-Jensen'
> Subject: RE: Problems with stringstream
> 
> 
> I'm running it on Mandrake Linux.  When I run it from the 
> command line - no
> output.  However when I run it from the ddd debugger, it 
> works fine!  Huh?!?
> 
> -----Original Message-----
> From: John Love-Jensen [mailto:eljay@adobe.com]
> Sent: Friday, October 25, 2002 10:22 AM
> To: Jessee, Mark
> Subject: Re: Problems with stringstream
> 
> 
> Using GCC 3.2 on Cygwin, your example worked perfectly as one 
> would expect.
> 
> Hmmm.
> 
> --Eljay
> 

RE: Problems with stringstream

[Andrea Bocci]

At 10.48 25/10/2002 -0600, Jessee, Mark wrote:
>Matt,
>
>Your example fails as well.  But I found if I modify it a bit (see below),
>it works fine.  Still not sure why though.  Thoughts?  Something to do with
>flushing the stream?

I guess you're right.
Probably the standard out is not automatially flushed at the end of the 
program, so you don't get the last output.

Does this...

#include <iostream>
#include <sstream>
#include <string>
using namespace std;

int main ()
{
    stringstream oss;
    string mystr;

    oss << "Sample string";
    mystr=oss.str();

    cout << mystr << endl;      // flushes stdout

    return 0;
}

...work ?

fwyzard

RE: Problems with stringstream

[Moore, Mathew L]

std::endl will flush the buffer (after adding a new line).  If you don't
want to add the newline then you can just flush() it:

  cout << mystr;
  cout.flush();

Do you need to add the extra strings as well, or does just the flush() work
for you?

I thought that the streams were automatically flushed when they reached the
end of their scope (at the end of your main function here).  Anybody know if
that is incorrect?

--Matt


> -----Original Message-----
> From: Jessee, Mark [mailto:Mark.Jessee@gdcanada.com]
> Sent: Friday, October 25, 2002 12:48
> To: 'Moore, Mathew L'; Jessee, Mark; 'gcc-help@gcc.gnu.org'
> Subject: RE: Problems with stringstream
> 
> 
> Matt,
> 
> Your example fails as well.  But I found if I modify it a bit 
> (see below),
> it works fine.  Still not sure why though.  Thoughts?  
> Something to do with
> flushing the stream?
> 
> #include <iostream>
> #include <sstream>
> #include <string>
> using namespace std;
> 
> int main ()
> {
>    stringstream oss;
>    string mystr;
> 
>    oss << "Sample string";
>    mystr=oss.str();
> 
>    cout << "get ready..." << endl;
>    cout << mystr;
>    cout << "all done" << endl;
> 
>    return 0;
> }
> 
> -----Original Message-----
> From: Moore, Mathew L [mailto:MooreML@BATTELLE.ORG]
> Sent: Friday, October 25, 2002 10:44 AM
> To: 'Jessee, Mark'; 'gcc-help@gcc.gnu.org'
> Subject: RE: Problems with stringstream
> 
> 
> I wonder if this problem can be narrowed down?  Does it take 
> this exact code
> listing to reproduce the problem?  Can you just print out a string?
> 
> 	string mystr("test");
> 	cout << mystr;
> 
> If your debugger produces the correct result, it would at 
> least seem that
> the stringstream portion is working correctly.  I wonder if 
> your stdout was
> remapped somewhere (is that possible?).
> 
> --Matt
> 
> 
> 
> > -----Original Message-----
> > From: Jessee, Mark [mailto:Mark.Jessee@gdcanada.com]
> > Sent: Friday, October 25, 2002 12:30
> > To: 'gcc-help@gcc.gnu.org'
> > Cc: 'John Love-Jensen'
> > Subject: RE: Problems with stringstream
> > 
> > 
> > I'm running it on Mandrake Linux.  When I run it from the 
> > command line - no
> > output.  However when I run it from the ddd debugger, it 
> > works fine!  Huh?!?
> > 
> > -----Original Message-----
> > From: John Love-Jensen [mailto:eljay@adobe.com]
> > Sent: Friday, October 25, 2002 10:22 AM
> > To: Jessee, Mark
> > Subject: Re: Problems with stringstream
> > 
> > 
> > Using GCC 3.2 on Cygwin, your example worked perfectly as one 
> > would expect.
> > 
> > Hmmm.
> > 
> > --Eljay
> > 
> 

Re: Problems with stringstream

[bjorn rohde jensen]

Hi guys,

  Input and output on unix systems are buffered.
std::cerr is usually line buffered, std::cout
is line buffered, when directed to a terminal
and block buffered, when connected to a file.
  In case of line buffered output, you dont see
any, unless you flush it, or write a newline
character to the stream, which causes the buffer
to be flushed.

Yours sincerely,

Bjorn

RE: Problems with stringstream

[Jessee, Mark]

Matt,

Your example fails as well.  But I found if I modify it a bit (see below),
it works fine.  Still not sure why though.  Thoughts?  Something to do with
flushing the stream?

#include <iostream>
#include <sstream>
#include <string>
using namespace std;

int main ()
{
   stringstream oss;
   string mystr;

   oss << "Sample string";
   mystr=oss.str();

   cout << "get ready..." << endl;
   cout << mystr;
   cout << "all done" << endl;

   return 0;
}

-----Original Message-----
From: Moore, Mathew L [mailto:MooreML@BATTELLE.ORG]
Sent: Friday, October 25, 2002 10:44 AM
To: 'Jessee, Mark'; 'gcc-help@gcc.gnu.org'
Subject: RE: Problems with stringstream


I wonder if this problem can be narrowed down?  Does it take this exact code
listing to reproduce the problem?  Can you just print out a string?

	string mystr("test");
	cout << mystr;

If your debugger produces the correct result, it would at least seem that
the stringstream portion is working correctly.  I wonder if your stdout was
remapped somewhere (is that possible?).

--Matt



> -----Original Message-----
> From: Jessee, Mark [mailto:Mark.Jessee@gdcanada.com]
> Sent: Friday, October 25, 2002 12:30
> To: 'gcc-help@gcc.gnu.org'
> Cc: 'John Love-Jensen'
> Subject: RE: Problems with stringstream
> 
> 
> I'm running it on Mandrake Linux.  When I run it from the 
> command line - no
> output.  However when I run it from the ddd debugger, it 
> works fine!  Huh?!?
> 
> -----Original Message-----
> From: John Love-Jensen [mailto:eljay@adobe.com]
> Sent: Friday, October 25, 2002 10:22 AM
> To: Jessee, Mark
> Subject: Re: Problems with stringstream
> 
> 
> Using GCC 3.2 on Cygwin, your example worked perfectly as one 
> would expect.
> 
> Hmmm.
> 
> --Eljay
> 

RE: Problems with stringstream

[Jessee, Mark]

I'm running it on Mandrake Linux.  When I run it from the command line - no
output.  However when I run it from the ddd debugger, it works fine!  Huh?!?

-----Original Message-----
From: John Love-Jensen [mailto:eljay@adobe.com]
Sent: Friday, October 25, 2002 10:22 AM
To: Jessee, Mark
Subject: Re: Problems with stringstream


Using GCC 3.2 on Cygwin, your example worked perfectly as one would expect.

Hmmm.

--Eljay

Problems with stringstream

[Jessee, Mark]

Hi,

I'm trying to build the following program using gcc 3.0.3.  It compiles okay
but when it runs there is no output.  When I compile and run on MS Visual
C++ the output is "Sample string" as expected.  I did a quick check of the
FAQ for this topic but couldn't find any information.  Any suggestions are
appreciated!

#include <iostream>
#include <sstream>
#include <string>
using namespace std;

int main ()
{
   stringstream oss;
   string mystr;

   oss << "Sample string";
   mystr=oss.str();

   cout << mystr;

   return 0;
}

Thanks,
Mark