[Digikam-users] command line tool to normalize exif orientation flag

[Remco Viëtor]

On Thursday 31 May 2012 17:09:25 John Stumbles wrote:
> On 31/05/12 16:21, Elle Stone wrote:
> 
> > To be doubly safe, make a backup of your main image folders before
> > using exiftool to change the orientation tag.
> 
> On a unix-ey filesystem with hard links doing
>    cp -rl <pictures_filetree> <backup_place>
> e.g.
>    cp -rl /home/john/pix /home/john/pix.20120531-backup
> makes an image of my main image folders in the backup location without 
> using (much) extra disk space, since only the directory entries of the 
> files are copied, not the files themselves.
> 
> It's not bulletproof: since the files are hard-linked any utility that 
> changes the contents of the file in one location without breaking the 
> link will change it in the other location as well.
> 

Also, to make the risks abundantly clear: anything that damages the file, will 
damage it for *all* locations, meaning that the original data is /lost/...

So, for me, hard-links *cannot* be considered as backups, you'll have to use a 
real copy for that (that actually copies the data to another location).

Hard links are very useful to give another 'view' on a collection of files, 
among other things, but please, please, do not even think of them as any form 
of 'back-up'... And we've seen in another thread that Digikam doesn't play 
nice with hard-linked files, either.

Remco

P.S. @John: this is not to attack you, but hard links are a slightly more 
advanced feature, and if someone thinks that they work as a backup, they could 
be in for a lot of grief...