I need to prepend text to the description fields of a bunch of jpgs. I found discussions of appending text (e.g., here and here), but not of prepending text. My destination tag is
mwg:description, and my understanding is that the current value of that tag is
$mwg:description, so, conceptually, I think I'm looking for something like this:
exiftool -mwg:description="Text to Prepend $mwg:description" *.jpg
but that just replaces the current description with
Text to Prepend; the existing description text is lost. Can someone help me with the proper incantation?