Re: [Chicken-users] Installing data files for eggs

[John Cowan]

On Fri, Oct 22, 2010 at 6:24 AM, Felix
<address@hidden> wrote:

> Well, the question is whether it is allowed on systems that use a
> strict policy on what directories can be written to on installation
> (my terminology may be wrong). So on debian systems the egg repository
> ends up somewhere in /var. What I'd like to know whether the same
> policy applies to $PREFIX/share, or more precisely: should the data be
> installed there or in /var ? Installing in the normal repository path
> ($PREFIX/lib/chicken/$BINVERSION or $PREFIX/var/<whatever>) is
> no big deal, and any extension can already install subdirectories
> by simple putting the directory name in the files-list in
> `install-extension'.

The constraint on share directories (or at least on /usr/share and
/usr/local/share) is that files placed there must be read-only (in
normal operation, obviously not during installation) and
architecture-independent.

For example, /usr/share/dict/words is the current system dictionary,
which meets both requirements.  Man pages also meet both requirements
and go in /usr(/local)/share/man (for historical reasons there is a
symlink at /usr/local/man to /usr/local/share/man).  Preformatted man
pages in plain text or HTML, being writable, are supposed to go in
/var/cache/man, but not every distro does this.

Stuff in /var is intended to be mutated in normal operation, like
/var/log (syslogs) or /var/mail.  In principle, if /usr and /var are
different partitions, you can mount /usr read-only except when
installing software (it can even be shared between homogeneous
computers using NFS), whereas /var must be mounted read-write and is
specific to a particular computer.