getting information from standard output ( C   )?
string s;
fstream fs("/dev/stdout", fstream::in);
fs >> s;

cat file_with_nulls

cat file_with_nulls > otherfile

./myprog > output.bin

char cstr[] = { 'H', 'e', 0, 'l', 'l', 'o', 0 };

std::string s1(cstr);  // wrong, gives you "He"
std::string s2(cstr, sizeof(cstr));  // correct

std::string result;
std::fstream fs( "/dev/stdout", std::fstream::in|std::fstream::binary );
while ( !fs.eof() ) {
  std::string b;
  fs >> b;
  result += b;
}
fs.close();

std::fstream out( "C:\tmp\test1.txt", std::fstream::out );
out.write( "aaanbbbccc", 13 );
out.close();