I'm looking to modify the EXIF/IPTC meta information in a Canon RAW file (.CR2). In particular, I'm trying to add title, description (subject) and keywords tags to the file before uploading it to dreamstime. However, I do not want to change the last modified date stamp of the file. exiftool moves the original file to a different name (it adds _original to the end of the filename) which has the original time stamp, so I could use touch -r to fix the time stamp of the newly created file, but I'm hoping there's a command line argument that does that automatically.

Indeed, such a command line argument exists: -P

So for example, to ensure that a .CR2 file has a given keyword, one could do:

exiftool -P -Keywords-=China somefile.cr2


exiftool -P -Keywords+=China somefile.cr2

removing the keyword first avoids listing the keyword twice (or even more times)