I want to call exiftool from a c image viewer program (gThumb), to get the metadata for hundreds of images (as part of the thumbnailing process).
exiftool works extremely well, except that it takes ~0.3s per file. I think that most of the time is actually spent initializing the program and perl, rather than actually generating the metadata.
Phil, have you considered adding a "daemon mode" to exiftool, so that it could be launched once and run persistently? Has anyone experimented with that?