This is easier to explain with an example. Imagine I have a directory structure as follows:
pics/cats/png/01.png pics/cats/png/02.png pics/cats/jpg/01.jpg pics/cats/jpg/02.jpg pics/dogs/png/01.png pics/dogs/png/02.png pics/dogs/jpg/01.jpg pics/dogs/jpg/02.jpg
I would like to rsync the "pics" directory to a destination, but on the destination I would like the following result, assuming the filter string for my leaf directories is "png":
pics/cats/png/01.png pics/cats/png/02.png pics/dogs/png/01.png pics/dogs/png/02.png
In addition, I would like to accomplish the following result as well: (as the png dirs are no longer necessary)
pics/cats/01.png pics/cats/02.png pics/dogs/01.png pics/dogs/02.png
It might be important to note that any directory might have the string "png" in it, but I only want to "filter" on the leaf directories, ie, directories that do not contain another directory.
It might be important to note also that I want to keep the contents of the "png" directories, even if they contain non-png files. Ie:
pics/cats/png/01.png pics/cats/png/02.txt pics/cats/jpg/01.jpg pics/cats/jpg/02.jpg pics/dogs/png/01.txt pics/dogs/png/02.png pics/dogs/jpg/01.jpg pics/dogs/jpg/02.jpg
pics/cats/png/01.png pics/cats/png/02.txt pics/dogs/png/01.txt pics/dogs/png/02.png
pics/cats/01.png pics/cats/02.txt pics/dogs/01.txt pics/dogs/02.png
Last item to note: The directory structure might be "n" deep. Ie:
pics/cats/house/tabby/png/01.png pics/cats/house/tabby/png/02.txt pics/cats/house/tabby/jpg/01.jpg pics/cats/house/tabby/jpg/02.jpg
If no easy way exists I'm sure I can just write a bash script to do it, but this seems like a use case that while not common, I'm sure crops up every now and then, and perhaps there is a name and flag for this operation.