[Sussex] Unix file permissions question

[Tony Austin]

I want to be able to set permissions on a directory such that group (a)
has read-only access and group (b) has read-write access.

Possibilities that I have considered include:-

1.  multiple symbolic links to the folder - but permissions are not
recognised on symbolic links
2.  multiple hard links - but this seems to be difficult if not impossible
to do and seems to lead to a multitude of other problems
3.  two layers of directories so that the upper layer has read-only and
the lower layer has read-write - this is not practical in my apllication
as I cannot alter the existing directory structure

I have Googled extensively on this and find that I am not the the first to
come across this dilemma.  The usual answer seems to be something like
"You shouldn't need more than one set of group permisssions because I have
never found it necessary in the 999 years that I have been using Unix. 
There is usually another way of doing what you need to do."

Unfortunately none of these sages has actually suggested what some of the
alternatives might be.

The only other answer seems to be on the lines of  "It's an application
problem, if your application doesn't handle it you could install software
to handle ACLs."  Well maybe, but this seems a bit heavy-handed.

Anyone her got any ideas?

Regards.

Tony Austin
Gigaday Computing Limited
http://www.gigaday.com
tony at gigaday.com



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