Hello, i am using the following code to redirect stdout to a pipe, then read all the data from the pipe to a buffer. I have 2 problems:

first problem: when i send a string (after redirection) bigger then the pipe's BUFF_SIZE, the program stops responding (deadlock or something).

second problem: when i try to read from a pipe before something was sent to stdout. I get the same response, the program stops responding - _read command stuck's ...

The issue is that i don't know the amount of data that will be sent to the pipe after the redirection.

The first problem, i don't know how to handle and i'll be glad for help. The second problem i solved by a simple workaround, right after the redirection i print space character to stdout. but i guess that this solution is not the correct one ...

#include <fcntl.h>
#include <io.h>
#include <iostream>

#define READ 0
#define WRITE 1
#define BUFF_SIZE 5

using namespace std;

int main()
{

  int stdout_pipe[2];
  int saved_stdout;

  saved_stdout = _dup(_fileno(stdout));            // save stdout 

  if(_pipe(stdout_pipe,BUFF_SIZE, O_TEXT) != 0 )   // make a pipe
  {    
    exit(1);
  }

  fflush( stdout );

  if(_dup2(stdout_pipe[1], _fileno(stdout)) != 0 ) //redirect stdout to the pipe 
  { 
    exit(1);
  }

  ios::sync_with_stdio();    
  setvbuf( stdout, NULL, _IONBF, 0 );

  //anything sent to stdout goes now to the pipe
  //printf(" ");//workaround for the second problem

  printf("123456");//first problem

  char buffer[BUFF_SIZE] = {0};
  int nOutRead = 0;
  nOutRead = _read(stdout_pipe[READ], buffer, BUFF_SIZE); //second problem
  buffer[nOutRead] = '\0';

  // reconnect stdout

  if (_dup2(saved_stdout, _fileno(stdout)) != 0 ) 
  {        
         exit(1);
  }
  ios::sync_with_stdio();

  printf("buffer: %s\n", buffer);
  }

Thanks, Alex