Re: [tlug] JPEG file timestamp vs EXIF timestamp (was: Ubuntu 13.10 clock problems (was: Ibus and Ubuntu based))

[Bruno Raoult <braoult@example.com>]

On Thu, Nov 14, 2013 at 3:41 AM, Lyle H Saxon <llletters@example.com> wrote:
> > There are many (hot) discussions on this subject. As I use Unix/Linux
> > for long time, I am comfortable with the fact than a copied file is
> > considered as a new file (the way "cp" works). Some people don't
> > agree.
>
> I don't consider the poor use of the term "modify" to mean
> "changeless copy" in exactly the same light, but close....

This is not a semantic issue.
I told you people don't agree on the Unix (and Posix) cp behavior.

I consider myself that when I create a file, the modify date should
be set to current time, and other attributes changed too, such as
ownership, etc... And when I copy a file, the new one is *created*
technically speaking, therefore the new timestamps.
There are options to preserve file times and some other attributes.
But they are options, not default behavior (and clearly written in "cp" manual).

I am not sure about your file manager setup and what it is supposed to do,

however.

> > And again, "exiftool '-DateTimeOriginal>FileModifyDate' dir" would
> > likely solve your issue if you really want to have correct filesystem
> > timestamp from EXIF data.
>
> Yeah - well, I suppose the most convenient thing to do would be to
> change the (nearly meaningless) file names generated by a camera into
> a date and time so I don't have to worry about erratic behavior by
> different software when moving pictures from one machine to another.
> Is that what "exiftool '-DateTimeOriginal>FileModifyDate' dir" would
> do for me?

No: This command would set the filesystem timestamp according to jpeg EXIF
information (if any). As you did not send the output of exiftool, I don't know
which EXIF data is available (i.e. created by your camera).
Maybe the following option (from exiftool manual) is what you want (to set a
filename according to the file EXIF "CreateDate" tag).

exiftool '-FileName<CreateDate' -d %Y%m%d_%H%M%S%%-c.%%e dir
  Rename all images in "dir" according to the "CreateDate" date and time, adding a copy
  number with leading '-' if the file already exists ("%-c"), and preserving the original
  file extension (%e).  Note the extra '%' necessary to escape the filename codes (%c and
  %e) in the date format string.

But again, your favorite photo management software must be able to sort pics

and display information according to their EXIF data, not filesystem's. Mine (shotwell) does.

Good luck.

br.

--
2 + 2 = 5, for very large values of 2.