File Write Permission Rules

Steve Mawer scm at datlog.co.uk
Mon Feb 13 22:40:32 AEST 1989


In article <306 at wubios.wustl.edu> david at wubios.wustl.edu (David J. Camp) writes:
>We have a strange situation where a program can write to a file even
>though it does not have write permission.
>                             I would have required write permission to
>the file itself in order that it be removed.
>-David-

I too, have thought this behaviour bizarre.  However, the (logical) answer
is that deleting a file does *not* involve writing to it, only to the
directory.  Therefore, if you can write to a directory, you can delete
the file.

If you want to protect your files, match the permissions of the file with
those of the directory.  (I know this is not a good answer if you want
users to be able to *create* personal files in the directory.)

-- 
Steve C. Mawer        <scm at datlog.co.uk> or < {backbone}!ukc!datlog!scm >
                       Voice:  +44 1 863 0383 (x2153)



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