C#

private void SendString(StringBuilder sb) {
	IntPtr pipe2=CreateFile(pipeName, GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
	Thread.Sleep(200);
	int count;
	bool OK=WriteFile(pipe2, sb, sb.Length, out count, 0);
	if (!OK) ... report error
	ClosePipe(pipe2);
}

// Writes data to a file at the position specified by the file pointer.
[DllImport("kernel32.dll", SetLastError=true)]
public static extern bool WriteFile(
	IntPtr hHandle,				// handle to file
	StringBuilder lpBuffer,			// data buffer
	int nNumberOfBytesToWrite,		// number of bytes to write
	out int lpNumberOfBytesWritten,		// number of bytes written
	uint lpOverlapped			// overlapped buffer
);