China DOS Union

I tried echo N|xcopy c:\txt d:\txt /d /u /p

But the result shown was as follows:

C:\Documents and Settings\Dell>echo N|xcopy c:\txt d:\txt /d /u /p
C:\txt\1.txt (Y/N)? N
C:\txt\15204.txt (Y/N)?
C:\txt\15204.txt (Y/N)?

C:\txt\15204.txt (Y/N)?

C:\txt\15204.txt (Y/N)? C:\txt\21195.txt (Y/N)? 0 File(s) copied

Why did it turn out like this?

Because what echo N sends is not just the keyboard scan code for N.
You can solve it with for ......... exist................, or write a binary file whose contents are all 4e, then use < to redirect it to xcopy's input.

Thanks to Michael for the helpful explanation, I basically understand the reason now, and I'm currently thinking of a way to solve it. Thanks again!

You can have a look here. I've already proposed adding an /I switch to the CP command, to automatically answer "No", that is, skip files that already exist:

http://www.cn-dos.net/forum/viewthread.php?tid=28739&fpage=1

How do I suppress the [y|n] in the sc command?