C / C++ / MFC

30-Nov-03 22:43

hi friends,
i have a c++ program like this :

#include "iostream.h"
int main()
{
cout << "John" << endl;
return 1;
}

The program will print "John" on screen.
Now my problem is that i want to print "Hello John Bye" on the screen without changing anything inside main function.
CAN SOMEBODY PROVIDE ME THE ANSWER.

Imran Farooqui30-Nov-03 22:57

Imran Farooqui

30-Nov-03 22:57

#include "stdafx.h"

using std::cout;
using std::endl;

class CTest
{
public:
  
   CTest()
   {
     cout << "Hello John bye" << endl;
   
     exit(0);
  }

};


int main(int argc, char* argv[])
{
   cout << "John" << endl;

   return 0;
}


CTest test;

Anonymous30-Nov-03 23:17

30-Nov-03 23:17

Hi Imran,
It will print ,"Hi John bye John" but i need "Hi john bye".

Antti Keskinen30-Nov-03 23:48

Antti Keskinen

30-Nov-03 23:48

Based on Imran's solution, here is a bit more customized version which does as desired.

#include <iostream>
using namespace std;<DIV>

class CFirst
{
public:
   CFirst() { cout << "Hi "; }
}<DIV>

class CLast
{
public:
   CLast() { cout << " Bye"; }
}<DIV>

CFirst object1;<DIV>

int main( int argc, char* argv[] )
{
  cout << "John" << endl;
  return 0;
}<DIV>

CLast object2;

This piece would print "Hi John\n Bye". Removing the line change from inside main is impossible, as far as I know, without doing some serious stream interception. All this seems unnecessary though. Just boot the line change from there, or pretend that you didn't notice it :P

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

cmk1-Dec-03 0:04

1-Dec-03 0:04

Actually this will/may put :
"Hi ByeJohn"
because both objects are initialized (constructors called) before main().

I say may, because as far as i know you can't count on the order that global objects will be initialized within a given init_seg.
Having said that you could use the
#pragma init_seg()
directives to put CFirst, CLast and main in different .cpp files and use init_seg(lib) for CFirst and init_seg(user) for CLast to ensure the order they were constructed ... but that seems like a whole lot of work to still get the wrong output. Smile | :)

...cmk

Save the whales - collect the whole set

Imran Farooqui1-Dec-03 0:03

Imran Farooqui

1-Dec-03 0:03

Please refer the code i wrote above:

In the constructor of CTest class, there is an exit(0) call. So this program will never enter the main function.

Trick is that, in C++, global objects are created before program enters the main function. So we created the object of CTest class as a global object. As such its constructor gets called in which we first print our desired string and then exit(0) gets calls and the program ends.

cmk30-Nov-03 23:55

30-Nov-03 23:55

What about as Imran had but :

CTest()
{
    cout << "Hello ";
}

~CTest()
{
    cout << " Bye";
}

... although you should really do your own homework. Wink | ;)

[edit]
Hmmm, this doesn't print the " Bye", altough the code goes there. Even adding cout.flush() doesn't print it. Looks like ostream system has been shut down by then. Using printf() does work in printing " Bye", but you need to eat the \n first, and adding \b doesn't seem to work ... hmmm
[/edit]

...cmk

Save the whales - collect the whole set

cmk1-Dec-03 0:32

1-Dec-03 0:32

Couldn't remember the console cursor movement functions (ala curses).
However, here is a hack that works (and is within the contraints given Smile | :)

), but not likely the solution you need :

#include <iostream>
using namespace std;

class CFirst{
public:   
	CFirst() {
		cout << "Hi ";
	}
	~CFirst() {
		printf("Bye\n");
	}
};
CFirst f;

#define  endl  ' '

int main( int argc, char* argv[] )
{
	cout << "John" << endl;
	return 0;
}

...cmk

Save the whales - collect the whole set

Mail-Monty1-Dec-03 0:33

Mail-Monty

1-Dec-03 0:33

Hello all,
please don't laugh Laugh | :laugh:

but here is one solution

#include <iostream.h>

#define cout cout << "Hello "
#define endl " Bye" << endl

int main(int argc, char* argv[])
{
cout << "John" << endl;
return 1;
}
Roll eyes | :rolleyes:

When all else fails read the manual

cmk1-Dec-03 0:36

1-Dec-03 0:36

Not laughing, as valid a solution as any, given the constraints. Smile | :)

...cmk

Save the whales - collect the whole set

Joaquín M López Muñoz1-Dec-03 0:40

Joaquín M López Muñoz

1-Dec-03 0:40

That's the kind of solution that pisses teachers off. I love it.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Anonymous1-Dec-03 2:53

1-Dec-03 2:53

hi,
this solution should result in compilation error, although i haven't checked it but we can't apply #define on the cout and endl like this.

Antti Keskinen1-Dec-03 10:43

Antti Keskinen

1-Dec-03 10:43

It isn't doable, because you #define cout as a part of itself.. Like, what you're doing is:

#define MAX_AMOUNT  MAX_AMOUNT + 20

Similar type of error.

Man I really wish that that thing would've worked, it would've been a kickass "spoil-a-teacher's-day" for some C++-course Smile | :)

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

Help on DirectSoundFullDuplexCreate8() ??

Monty²1-Dec-03 20:05

Monty²

1-Dec-03 20:05

IT REALLY WORKS like a charm ,
go ahead try to compile , it works !!!
Poke tongue | ;-P

When All Else Fails Read the Manual

elza30-Nov-03 21:25

elza

30-Nov-03 21:25

anybody out there ever used DirectSoundFullDuplexCreate8() of the DirectSound???

I keep getting E_INVALIDARG...can't figure out the reason..Code as follows.. Can anyone figure out where the prob is???

HRESULT hr;
DSBUFFERDESC dsbdesc;
DSCBUFFERDESC dscbdesc;
DSCEFFECTDESC dsceffectdesc;
WAVEFORMATEX Capwfx;

LPDIRECTSOUNDFULLDUPLEX8 m_pDSFullDuplex = NULL;
LPDIRECTSOUNDBUFFER8 m_pDSBOutput = NULL;
LPDIRECTSOUNDCAPTUREBUFFER8 m_pDSBCapture8 = NULL;

// Initialize COM
if( FAILED( hr = CoInitialize(NULL) ) )
return DXTRACE_ERR_MSGBOX( TEXT("CoInitialize"), hr );

memset(&Capwfx, 0, sizeof(WAVEFORMATEX));
Capwfx.wFormatTag = WAVE_FORMAT_PCM;
Capwfx.nChannels = 1;
Capwfx.nSamplesPerSec = 16000;
Capwfx.nBlockAlign = 4;
Capwfx.nAvgBytesPerSec = Capwfx.nSamplesPerSec * Capwfx.nBlockAlign;
Capwfx.wBitsPerSample = 16;

// Obtain Sec buffer
ZeroMemory( &dsbdesc, sizeof(DSBUFFERDESC) );
dsbdesc.dwSize = sizeof(DSBUFFERDESC);
dsbdesc.dwFlags = 0;
dsbdesc.dwBufferBytes = 3 * Renwfx.nAvgBytesPerSec ;
dsbdesc.dwBufferBytes = 0;
dsbdesc.lpwfxFormat = &Capwfx;

//DS Capture Effects Struct
ZeroMemory( &dsceffectdesc, sizeof(DSCEFFECTDESC) );
dsceffectdesc.dwSize = sizeof(DSCEFFECTDESC);

//DS Capture BUffer Desc
ZeroMemory( &dscbdesc, sizeof(DSCBUFFERDESC) );
dscbdesc.dwSize = sizeof(DSCBUFFERDESC);
dscbdesc.dwFlags = DSCBCAPS_CTRLFX;
dscbdesc.lpwfxFormat = &Capwfx;
dscbdesc.dwBufferBytes = 250000;
dscbdesc.dwFXCount = 1;
dscbdesc.lpDSCFXDesc = &dsceffectdesc;

//Effect specified by guidDSCFXInstance must be in software

dsceffectdesc.dwFlags = DSCFX_LOCSOFTWARE;
dsceffectdesc.guidDSCFXClass = GUID_DSCFX_CLASS_AEC;
dsceffectdesc.guidDSCFXInstance = GUID_DSCFX_MS_AEC;

if( FAILED( hr = DirectSoundFullDuplexCreate8(g_pcGuidCaptureDevice,g_pcGuidRenderDevice,&dscbdesc,&dsbdesc,NULL,DSSCL_PRIORITY,&m_pDSFullDuplex,&m_pDSBCapture8,&m_pDSBOutput,NULL)))
return DXTRACE_ERR_MSGBOX( TEXT("DirectSoundFullDuplexCreate8"), hr );

return S_OK;

Re: Help on DirectSoundFullDuplexCreate8() ??

Roger Allen1-Dec-03 1:45

Roger Allen

1-Dec-03 1:45

I was only doing my first Dx stuff yesterday, but dont you need:

Capwfx.dwSize = sizeof(WAVEFORMATEX);

You have the equivalent for the other structures

Roger Allen - Sonork 100.10016
If your dead and reading this, then you have no life!

Re: Help on DirectSoundFullDuplexCreate8() ??

elza1-Dec-03 1:56

elza

1-Dec-03 1:56

WAVEFORMATEX Capwfx;

Capwfx is an object of WAVEFORMATEX so I don't think we need to do that.
Moreover Capwfx does not have a member called dwsize..

anyhting else u can think of?

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Anonymous30-Nov-03 21:13