Copy keyword to Exif:ImageDescription

[Xof60]

Hello,
I just start working with ExifTool.

I will reorganising my old jpg-files and like to copy or move the keywords (-xmp-dc:Subject) into the Xmp:Description (-XMP-dc:Description) and Exif:ImageDescription (-IFD0:ImageDescription).
Can this be done with ExifTool for a folder with several hundreds of files?

Thank you very much for your support.

[StarGeek]

This can be done, but it needs some clarification.

Do you wish to overwrite Description and ImageDescription?  Or append the contents of Subject to those tags?

To overwrite (replace FileOrDir with the files or directory to process):
exiftool "-Description<Subject" "-ImageDescription<Subject" FileOrDir

To append
exiftool "-Description<Subject" "-Description<$Description $Subject" "-ImageDescription<Subject" "-ImageDescription<$ImageDescription $Subject" FileOrDir
If either Description or ImageDescription doesn't exist for a file, then a minor error is thrown but can be safely ignored.

[Xof60]

Thankyou, that saved me a lot of time.