Using exiftool to import photos from memory-cards

[Andreas Spindler]

A few month ago I posted a short script to import files from memory cards into a preview-directory:

    function import() {
                local dcimdir="$1" previewdir="${2:-.}"
                exiftool -r -P '-FileName<DateTimeOriginal' \
                    -o dummy/ \
                    -d "$previewdir/%Y-%m-%d/%%f%%-c.%%le" \
                    "$dcimdir/"
    }

The case is that Exiftool has no explicit copy-option. Without the dummy-directory files would be moved away from the card.

In his response Phil explained that -d just specifies how the tag-to-filename conversion is done. If you then wonder where the %Y-%m-%d part comes from, since only the FileName tag is set, not the Directory tag, read this https://exiftool.org/filename.html. There the "-o dummy/" idiom is explained. From this text one may guess that the dummy-directory is never created. This is not exactly true.

In December 2010 I bought a new camera and made some photos without having set its clock. The EXIF:DateTimeOriginal tag contains just zeroes for these photos; at least this is what XnView says. Exiftool prints

Warning: No writable tags found

Then Exiftool creates the dummy-directory and copies all photos without shooting time there. The filename was not changed; in particular it ignored my -d spec.  The rest of the photos on the card - made with a correct clock setting - are copied to the directory specified with -d. I then found the dummy-directory rather by accident, after I already counted my early photos for lost.  

There are maybe good reasons for these behaviors.
Nevertheless my feeling now is that there's no straigt way to "pursade" Exiftool to copy files from a to b or fail.

For the moment I upgraded -o dummy/ into -o "$previewdir/".
But I suppose Exiftool should have copied the photos into 0000-00-00/ subdirectories, rather than disposing files under two different file- and directory-patterns.  

[Phil Harvey]

You could add -if '$dateTimeOriginal' to the command to only process images containing the DateTImeOriginal tag.

Otherwise, you are correct, the images would be copied to the dummy directory.

An alternative would be to add '-filename<filemodifydate' before setting filename from DateTimeOriginal.  Since FileModifyDate always exists, then it would be used for files where DateTimeOriginal is missing.

- Phil

[Andreas Spindler]

Thanks for the quick answer!
So

    function import() {
        local dcimdir="$1" previewdir="${2:-.}"
        exiftool -r -P -v0 \
            '-FileName<FileModifyDate' \
            '-FileName<DateTimeOriginal' \
            -o dummy/ \
            -d "$previewdir/%Y-%m-%d/%%f%%-c.%%le" \
            "$dcimdir/"
    }

should be the safest way of copying files, i.e. the dummy-directory is never used?

It's quite simple. Sometimes you miss the wood for the trees.  

[Phil Harvey]

Yup, that should work.