i found that binary has a suid bit, group and other just have x bit can't be copy by user, like /usr/bin/passwd.
so the conclusion is, only root can prevent casual copy of file
i think it just for security reason, suid bit can't be copied
thank you all
On Sat, Feb 23, 2002 at 10:44:37AM -0600, Kevin Krieser wrote:
> A way that would work for special cases is taking away all but owner read
> permissions, then using a SUID bit on the program{s} that are allowed to
> actually read the file. If these programs don't provide a way to make
> another copy of the file, and don't just output the file to the screen in a
> way that can be redirected, you have prevented casual copying.
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Robert Canary
> Sent: Saturday, February 23, 2002 10:11 AM
> To: [EMAIL PROTECTED]
> Subject: Re: deny copying files
>
>
> Depends on what your trying to keep in tact. Cat file1 > file2 will
> copy all contents but the file image and timestamp has changed. So if
> your using any sort of original verification schemes you could detect a
> illegal copy. However, if your trying to prevent people from simply own
> the file on their system then their is nothing you can do while allowing
> read permissions.
>
> Depending on the file format (ie PDF), you can set security setting to
> not allow things like save or print. But those feature are dependant on
> the viewer application not the file or the filesystem permissions.
>
> Duncan Hill wrote:
> >
> > On Sat, 23 Feb 2002, Lewi wrote:
> >
> > > it that possible to restrict file to not able be copying but still can
> be
> > > see the contents.
> >
> > If I can view the contents, I can copy it.
> >
> > cat file1 > file2
> >
> > Hey presto, copied without using cp, and only by viewing it.
> >
> > _______________________________________________
> > Redhat-list mailing list
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> > https://listman.redhat.com/mailman/listinfo/redhat-list
>
> --
> robert canary
> system services
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>
>
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--
ichtus
------
Lewi Supranata .K
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