Re: Meaningless symlink redirection in Edgy for qmake

Trent Lloyd <lathiat@xxxxxx> writes:
> On Sun, Mar 18, 2007 at 06:20:48PM +0530, Shriramana Sharma wrote:
>> In Edgy I do:
>> 
>> $ cd /usr/bin
>> $ ls -l qm*
>> lrwxrwxrwx 1 root root      23 2007-01-27 22:48 qmake -> 
>> /etc/alternatives/qmake
>> -rwxr-xr-x 1 root root 2034776 2006-10-23 18:16 qmake-qt3
>> -rwxr-xr-x 1 root root 2064732 2007-02-12 23:27 qmake-qt4
>> $ ls /etc/alternatives/qmake -l
>> lrwxrwxrwx 1 root root 18 2007-02-13 15:24 /etc/alternatives/qmake -> 
>> /usr/bin/qmake-qt3
>> 
>> Is there any meaning to this unnecessary symlink redirection? The 
>> /usr/bin/qmake symlink could well directly point to the qmake-qt3 binary 
>> in its own folder rather than point to a file under /etc which points 
>> back to the /usr/bin folder.
>> 
>> If there is no meaning, then this can be rectified.
>
> This is part of the Debian alternatives infrastructure
>
> Some user-orientated information on how this works is available here
> http://www.debian-administration.org/articles/91

Moreover, Trent didn't mention the *why* explicitly here:

The reason those symlinks exists -- and various other tools including
'vi' will be the same -- is because there are multiple competing tools
that provide 'qmake'.

In this case you may want 'qmake' to be the QT3 version or you may want
it to be the QT4 version.

With vi you may want nvi, vim or one of the other vi options to be the
"default" vi.


So, yes, there is a meaning.  There is also a good reason why it
indirectly links through /etc -- you can share /usr via NFS between
multiple machines and maintain different 'alternatives' on them.

Regards,
        Daniel
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