How to attach to other Process's stdin?

[egrath]

Hi,

i currently try to write to a other's process standard input. I am using the OpenProcess Function and then the DuplicateHandle Function to get the Handle of the other's stdin.

Below is my non-working code:

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

int	main( int argc, char* argv[] )
{
	HANDLE hProcess, hMyProcess;
	HANDLE hInput;
	unsigned int nProcess;

	if( argc != 2 ) {
  fprintf( stderr, "illegal arg count\n" );
  exit( -1 );
	} else {
  nProcess = atoi( argv[1] );
	}

	fprintf( stdout, "Attaching pro Process %d ... ", nProcess );
	if(( hProcess = OpenProcess( PROCESS_ALL_ACCESS, TRUE, ( DWORD ) nProcess )) != NULL ) {
  fprintf( stdout, "OK\n" );
	} else {
  fprintf( stdout, "FAILED\n" );
  exit( -1 );
	}

	hMyProcess = GetCurrentProcess();

	fprintf( stdout, "Trying to get STDIN Handle from Process ... " );
	if( ! DuplicateHandle( hProcess, GetStdHandle( STD_INPUT_HANDLE ), hMyProcess, &hInput, 0, TRUE, DUPLICATE_SAME_ACCESS )) {
  fprintf( stdout, "FAILED\n" );
  fprintf( stdout, "%08X\n", GetLastError());
  exit( -1 );
	} else {
  fprintf( stdout, "OK\n" );
	}

	CloseHandle( hInput );
	return 0;
}

Does anyone see why this doesn't work? Do i have any logical errors?

Thanks, Egon

[egrath]

Hi,

found out that it's impossible to connect to another's process stdin/stdout/stderr Handle when you are not the father of that process. It's a security thing.

Egon