Question on replace of tag-values

[herb]

Hello Phil,

to replace a specific tag-value with
exiftool -tag-=<value> -tag=<newvalue>
is a wonderful feature. Thanks for it.

Now I ask whether this feature can be combined with copying a tag-value to another tag.

The following example
exiftool -software-<$model <image>
worked as expected: software was deleted only in case of the existing value of software was identical to content of $model.

But e.g. the following examples
exiftool -software-<$model -software<$make <image>
exiftool -software-=ABC -software<$make <image>
exiftool -software-<$model -software=MAKE <image>
did not work. Independent of value of software its new value always was content of $make, resp. MAKE.

Do I something wrong or have I overseen a specific detail?

Thanks for your comments/help in advance.
Best regards
Herb

[Phil Harvey]

Hi Herb,

Rather, it seems that I have overlooked something...

I'll look into this.

- Phil

[Phil Harvey]

Ah.  Silly me.  I wasn't thinking.  This is the reason (from the -tagsFromFile documentation):

            5) The normal behaviour of copied tags differs subtly from that of
            assigned tags for list-type tags.  When copying to a list, each
            copied tag overrides any previous operations on the list.  [...]

            Similarly, -addTagsFromFile must be used when conditionally
            replacing a tag to prevent overriding earlier conditions.

So a command would be:

exiftool -addtagsfromfile @ "-software-<$model" "-software<$make" FILE

- Phil

[herb]

Hello Phil,

thanks for the private lession. It works great.

Best regards
Herb

[herb]

Hello Phil,

sorry annoying you again.
Yesterday I did only a quick test which was working properly.
My interpretation of your comment is, that -addtagsfromfile @  has always to be added in case of a $-variable comes into play.

Repeating all tests I have seen the following:

exiftool -software-<$model -software<$make <image> and
exiftool -software-=ABC -software<$make <image>
with correct replace-value: -software is deleted but not replaced
with different replace-value: is working as expected

exiftool -software-<$model -software=MAKE <image> is still not working

What must I do?

Best regards
Herb

[Phil Harvey]

Hi Herb,

I don't see -addtagsfromfile in any of these commands.

- Phil

[herb]

Hello Phil,

yes, you are right. Editing this post I was so concentrated on the tags itself that I did not add -addtagsfromfile @ here inside the post. Working with DOS-box I of course used it. So I will repeat my commands: ( but characters " - necessary in DOS-box - are still omitted here):

exiftool -addtagsfromfile @ -software-<$model -software<$make <image> is working properly

exiftool -addtagsfromfile @ -software-=ABC -software<$make <image>
with correct replace-value ABC: -software is deleted but not replaced
with different replace-value ABC: is working as expected

exiftool -addtagsfromfile @ -software-<$model -software=MAKE <image> is also not working
Independent of replace-value MAKE is always set.


Sorry again that I gave not all details editing my previous post.

Best regards
Herb

[Phil Harvey]

Hi Herb,

In your 2nd command you've got the -addTagsFromFile in the wrong location.

            4) The order of operations is to copy all specified tags at the
            point of the -tagsFromFile option in the command line.

You need to put it after the -=.

Also, see common mistake 5b.

But you are right that the 3rd command doesn't work.  I'll look into this.

- Phil

[Phil Harvey]

Hi Herb,

The problem with the 3rd command was in ExifTool.  This will be fixed in version 10.61.

Thanks for pointing this out.

- Phil

[herb]

Hello Phil,

thanks for the corrections in version 10.61 and thanks for being so patient.
I have retested it and it works great.

Best regards
Herb

[Phil Harvey]

Hi Herb,

Great.

- Phil