ClearCase: Can I hijack a file in dynamic view?

Question

I am working in a dynamic view in Unix platform. I need to hijack a file temporarily and cancel the hijacking later. But the command chmod +w filename is not working.
I get the message chmod: WARNING: can't change filename.
I can change the read-only attribute of the file from a snapshot view in windows.

Questions:

1. Is hijacking possible in a dynamic view? If yes, how?
2. Is there a cleartool command to cancel hijacking of a file?

Answer 1

One of the side-effects of a dynamic view is that ClearCase will control the attributes of the file you access to through the network, as opposed of a snapshot view (where everything is copied on your hard drive).

1/ Yes it is possible, even though it isn't really an "hijacked" state.
The dynamic equivalent is named "eclipsed": the idea is for a private file of the same name than a versioned one to take the place ("eclipsing") of the versioned file.

You simply make a copy of that file as a backup, and make that file invisible by not selecting it (type "cleartool edcs" anywhere within the dynamic view):

element /vob/path/to/file -none

Then you rename the backup copy, restoring its original name.

2/ to undo an eclipsed file, you simply move it or delete it.
The versionned file (eclipsed by the private one) is restored instantly.

See IBM article "About eclipsed files and ClearCase" for more.

Answer 2

Why not doing an unreserved checkout?

cleartool checkout -unreserved filename