How to create a Junction Point using WinApi?

Question

There is CreateHardLink function to create Hardlinks.(Since Win2000)
And there is CreateSymbolicLink function since Vista has been released.

But why isn't there a CreateJunction?

How does mklink make a junction?
And How do I write codes to make junction in my app?

score 14 · Accepted Answer · answered Sep 01 '10 at 12:27

14

They're reparse points, so FSCTL_SET_REPARSE_POINT is the magic FSCTL. Here's an example, never tried it but seems right:

http://www.flexhex.com/docs/articles/hard-links.phtml

-scott

answered Sep 01 '10 at 12:27

snoone

5,409
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19

@efotinis where did you get this info from? Documentation has no mention of this. – Teivaz Jul 23 '19 at 09:23
@teivaz, I don't know why I wrote that... My mistake. – efotinis Jul 26 '19 at 20:44

score 6 · Answer 2 · answered Apr 20 '12 at 20:32

There's currently no built-in single function for creating junctions like there is for symbolic links or hard links. Like snoone said, it's a reparse point, so you have to use DeviceIoControl to interact with it. If I remember correctly, the source he linked is the same source I played around with when I was trying to figure this out, and I don't think I ran into any issues with it.

Alternatively, if you're not against using an external library in your application, and you're going to need functionality for reading/checking/deleting junctions, you might want to look into reparselib, which is a pretty decent library wrapping junctions, symbolic links, mount points, and custom reparse points.

How to create a Junction Point using WinApi?

2 Answers2