Allow user to create files but not edit/delete

[Colin Law]

On 7 June 2011 13:43, Loïc Grenié <loic.grenie at gmail.com> wrote:
> 2011/6/7 Colin Law <clanlaw at googlemail.com>:
>> Is there a way to setup permissions and ownership such that a user can
>> create new files in a particular directory, and can read existing
>> ones, but cannot edit or delete existing ones?  By giving ownership of
>> the directory and existing files to root,  with permissions 777 on the
>> directory and 774 on existing files, then the user has read-only
>> access to existing files and can create new files, but unfortunately
>> he can delete existing files and re-create them, hence effectively
>> editing them.  Is there any way around this?
>
> chmod 1777 dir

Of course, I did not read far enough down the ubuntu permissions wiki
page [1], I switched off when it started talking about Posix ACLs,
thinking it had finished with the basic stuff.

Many thanks

Colin

[1] https://help.ubuntu.com/community/FilePermissions