bruxxx

Q: Access Special Info in files, like photos, audio, video

I am trying to automate the sorting of files using shell scripting.

I want to file different things in different places based on things like:

 

- what camera they were taken from

- what resolution the picture is

- perhaps GPS location

- for mp3's maybe audio compression or codec

- for audio files, are the podcasts, from an iPhone, voice recorder.

 

For example I dump files into a directory and want a cron job to take

any .jpg files and figure out where they came from?  Were they downloaded

from the Internet, saved from email, taken from a camera or phone, if so

what device.

 

I know there is data somewhere in these files, and that finder, preview

and other programs can find it and get at it, but is there a way to do it

on my own?

 

I have heard of resource forks but I really have no idea what they are or

how to access them.  If I could figure that out, or even where the data

might be inside the file and I could pull it out with shell commands, but

where is any of this data documented?

 

Just a pointer for jpg's, mp3's. mov's, mp4's would be a great start.

iMac, OS X Yosemite (10.10.3), 24",120G SSD,6GRAM,2T home,4T TM

Posted on Jan 15, 2016 12:52 AM

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Q: Access Special Info in files, like photos, audio, video

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  • by Mark Jalbert,

    Mark Jalbert Mark Jalbert Jan 15, 2016 7:06 AM in response to bruxxx
    Level 5 (4,649 points)
    Jan 15, 2016 7:06 AM in response to bruxxx

    Metadata is stored in multiple file forks or streams (data forks, extended attributes, resource forks) on HFS+.  These days, resource forks are rarely used. Apple supplies command line metadata readers- xattr and mdls but these tools lack some of the functionality that you are looking for. I recommend using Phil Harvey's exiftool in conjunction with the Apple supplied tools.

  • by bruxxx,

    bruxxx bruxxx Jan 15, 2016 12:40 PM in response to Mark Jalbert
    Level 1 (39 points)
    Mac OS X
    Jan 15, 2016 12:40 PM in response to Mark Jalbert

    Thanks Mark.  I will check it out.

     

    In wikipedia they mention this:

    From the POSIX interface, the resource fork could be accessed as filename/..namedfork/rsrc or as filename/rsrc; the shorter form was deprecated in OS X 10.4 and removed completely in Mac OS X 10.7


    I did not really get far with that other than they actually do show up under the ls command.


    I'm trying to find a way to do this programmatically in a script.

    I guess there are two parts to this:

    1. what kind of files have what kind of data

      2. how to access and retrieve the data associated with a given file type.

  • by Roote,

    Roote Roote Jan 17, 2016 12:16 AM in response to bruxxx
    Level 2 (417 points)
    Jan 17, 2016 12:16 AM in response to bruxxx

    Hi bruxxx. For drag-and-drop convenience of a GUI app to view the attributes and metadata of files, check out Orange Card.