[TAG] problem in coding of problem in linux

[Kapil Hari Paranjape]

Hello,

On Tue, 27 Nov 2007, Smit Jadhav wrote:
> i m student in computer science . i m doing a project in linux about
> security systems
> my concept is when a user tries to open a proteected file or folder he must
> be redirected to a other file or folder specified by us
> their is some sort of linking have to be done but how i dont know pls send
> any help message on my email id

One way this can be done is to preload an alternative to the "open"
file system call.

Another way is to create a new file-system kernel module which
implements the appropriate open call for files within that particular
file-system.

The "union" file-system concept is that if a file cannot/should not be
written to then a copy of this file is created in another location and
this copy is written to. This has been implemented in both the above
ways.

The "cowdancer" Debian package implements the "preload" way.

The "aufs" and "unionfs" kernel modules implements it the file-system
way.

All three programs are available under FOSS licenses. May the source
be with you!

Kapil.
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