Re: ocaml 3.04-3 uploaded

[barbier@linuxfr.org (Denis Barbier)]

On Mon, Jan 14, 2002 at 03:06:15PM +0100, Sven wrote:
[...]
> Mmm, Xavier told me that ld.conf was built using /etc/ld.conf as example, so
> it is more a configuration file.
> 
> Also it makes sense to let users modify them by hand, imagine people adding a
> homebuilt library or something such, without any knowledge of how debian
> works.
> 
> That said, we could imagine handling 2 such databases ?

This indeed looks like a good idea.  Here is a suggestion:
  * /etc/ocaml/paths: configuration file which is manually edited 
    by sysadmins
  * /var/lib/ocaml/dpkg-paths: file automatically modified by dpkg
    (its name is dpkg-paths in this mail to distinguish it from the
    previous one, but it could be /var/lib/ocaml/paths).
  * /usr/lib/ocaml/ld.conf: this file is generated by merging the 2 previous
    ones.

File syntax:
i.  paths:
     <directory>     <action>
    where
      * directory is ..... guess what?
      * action:
         add        add a directory to search path before system wide settings
         addafter   add a directory to search path after system wide settings
         discard    remove a directory from search path even if it is defined
                    in dpkg-paths
ii. dpkg-paths:
     <directory>     add     <package>
    where <package> is the name of the package which inserted this entry.

Thus both files can be described by a similar syntax:
     <directory>     <action>    <package>
the 3rd field being optional.
Allowing comments (with an hash sign for instance) would be nice.

The ocaml-ldconf is used to insert and remove entries from dpkg-paths,
and generate ld.conf.
It could accept the following options:
  -p package     sets package name
  -a dir         adds a line `dir add package' into dpkg-paths if such
                 a line does not exist
  -r dir         remove lines `dir add package' from dpkg-paths if found
  -n             do not update ld.conf

When invoked without -n flag, ocaml-ldconf regenerates ld.conf this way:
  * it reads paths line by line, and builds
     a) D1: list of directories to insert before system dirs
     b) D2: list of directories to insert after system dirs
     c) I:  list of directories to ignore
  * after that, it reads dpkg-paths line by line, and builds a directory
    list D3 by skipping those found in I.
Then D1+D3+D2 is written into /usr/lib/ocaml/ld.conf
It would also be nice if a warning line could be added to ld.conf to
prevent users from manually editing this file.

Last, ocaml-ldconf could be called directly by sysadmin to update ld.conf
after editing paths, or by maintainer scripts with arguments:
  * in postinst:
      ocaml-ldconf -p package -a dir1 -a dir2 -a dir3
  * in postrm:
      ocaml-ldconf -p package -r dir1 -r dir2 -r dir3

Denis