I'm already working with duplicate files, so backups are not an issue.

You're absolutely right - I don't understand perl. And many other things, as well. But I learned to do a simple find/replace with it, in this format:

Code:

perl -pi -e 's/read/write/g' /path/to/file

My plan was to use that syntax, except to add the recursive flag and point it at the dir like so:

Code:

perl -pi -e -r 's/^<string>com.apple.PhotoBooth</string>\n$//g' ~/Library/Compositions/

But when I went online to find the newline symbol, I saw that, in their examples, they put the filepath ahead of the command, so I tried it that way, thinking I'd remembered wrong. I also should've used the beginning and end of line markers since I'm grabbing the whole line.
Could you explain what you're doing with your line? Should that colon after the match operator be a slash? I assume that's a match operator, anyway. And why match (m) instead of substitute (s)? Thanks!

---------- Post updated at 05:19 PM ---------- Previous update was at 05:17 PM ----------

I started off doing it with BBEdit's find/replace, but there's about twenty files, so I wanted a recursive solution. I don't have PlistBuddy in my installation, although there is another .plist editing app. It seemed easier to edit it as a flat file.

---------- Post updated at 05:20 PM ---------- Previous update was at 05:19 PM ----------

That makes sense.