Date format

[gnespolino]

Hello, first of all thank you to Phil and all devs involved in this wonderful piece of code.
I'm writing a java application to catalog and query images and I'm very interested in extracting meta data using exiftool.
I already looked around and found some projects that already wrapped exiftool and expose a java api to use this tool, but you know developers too many times like to reinvent the wheel.
Basically I'm developing a spring boot application which will act as a daemon, monitoring source folder(s), detect changes and extract/update metadata accordingly into some kind of store. Then  I'll expose rest services to query this database basically in every possible way.
I'm doing this as a hobby, since I tried most photo management software out there and none satisfied me completely. Then will come a web interface to tide everything up.
To make a long story short, I'm developing a new java api to extract metadata using exiftool, using a pool of thread, taking advantage of stay_open, recursive, json format, group tags etc. and trying to apply all best practice I can, so to keep the code clean and the most agnostic as possible, I need to extract data using -n (no print conversion) option (which in as far as I understand should return "raw" data).
Unfortunately I'm observing that dates are returned as ISO strings instead, even if "-d %s" is specified.
Basically with "-d %s" I can have dates as epoch, but other fields are formatted in a human readable way, while when using "-n" all field are machine readable except dates which are still human readable. Using both has same behavior as "-n" alone.
So, does anyone knows how to have all fields machine readable, using epoch for dates ?

Giuseppe

[Phil Harvey]

Hi Giuseppe,

The "machine-readable" data format that ExifTool uses is equivalent to the EXIF date format.  If you want seconds since the epoch, you can use -d %s, but you can't do this with -n because that would disable the conversion.  If you really need ExifTool to convert to seconds since the epoch with -n for the other tags, you could do this using a complicated -api filter option, but I would think it would be easier to do this on your side in the Java code.

- Phil

[gnespolino]

Hey Phil, thank you for your answer!
probably on my side it's better to parse dates than all other tags, so I'll go through that way

Great job and thank you. ExifTool is a masterpiece!