Piping multiple files in and out for a single operation?

[clement.nardi]

Hello,

I'm working on an application whose job is to manage the transfer of the pictures on my camera's memory card to my computer.
In the process, I geotag these pictures using exiftool.

Today I do this in 3 steps:
- copy all the pictures to a temporary folder
- launch exiftool to geotag the pictures in place:
exiftool -config gps.config -geotag gps/* -progress -overwrite_original -P -if not $GPSLatitude tempfolder/
- move the pictures to their final destination

This is working fine, but I would like to improve this by avoiding to copy the files to a temporary folder and piping them through exiftool instead.
I checked the command line documentation and found that this is possible:
cat /memorycard/DSCF7386.JPG | exiftool -geotag gps/* - > ~/pictures/DSCF7386.JPG

However, I can't consider doing this file by file because of the GPS track files loading overhead.
Actually, loading the track files is as long as processing ~100 pictures, depending on the number of track files.

Then I checked the -stay_open option, but I don't see how this could help.

Is there a way to load some gps track files into exiftool, and then pipe multiple files through it?
Or do you see another way?


If not, then I started to consider another option, which is to call the perl routines from Geotag.pm directly from my application. But this seems a bit complex to do since my application is written in C++ and my primary target is Windows. I assume I need to embed perl in my executable, right?
How is it done for exiftool.exe? I couldn't find the source code of the windows executable, is it available somewhere?

Best regards,
Clement

[Phil Harvey]

Hi Clement,

Why not let ExifTool move the files for you.  Specify the memory card as the source, and use the -o option to specify the finale directory.  You can do this and geotag the images in a single command.

- Phil

[clement.nardi]

Hi Phil,

Thanks for your prompt answer!

Indeed, this would work for a memory card. But there are two reasons why I did not consider this:
- It will not work if the pictures are on a smartphone or camera connected to the PC through protocols such as MTP or PTP. One of the key features of my app is to support these protocols.
- I may reach limitations to the command line length, as I would need to pass each file path individually... I already encountered this issue before, it's one of the reasons why I copy everything to a temporary location first.

[Phil Harvey]

OK, well then to answer your original question.  There is no way to pipe multiple files through exiftool because this would require a mechanism to be able to distinguish the individual files on output.

- Phil