OS X (Apple)

I'm new to playing with the command line on OS X and am puzzled by the response I am getting from the find command. I have a file structure similar to the following

/Volumes/
../Drobo/
../../Pictures/
../../../Image 1/
../../../../Image 1.jpg
../../../../Previews/
../../../../../Image 1.jpg
../../../Image 2/
../../../../Image 2.jpg
../../../../Previews/
../../../../../Image 2.jpg

and so on for hundreds or in some cases thousands of directories at the image level. I am trying to pull all of the jpg files that are under the main group to the Pictures/ level without having them overwritten by any of the same name files from the Previews/ directories. To do this, I've set up the following two commands:

find "$PWD" -type d -iname "Previews" -exec rm -R {} \;
find "$PWD" -type f -iname "*.jpg" -exec mv {} . \;

which I execute from the Pictures/ directory level. It works, but a few things puzzle me.

1. This only works if I use the $PWD variable. If I use a . there, the rm command fails.

2. I have to use the -exec rm to succeed. If I try using the -delete flag on the first command, it fails.

3. Even though the Previews/ directories are being deleted, I receive the following error message on the terminal:

find: /Volumes/Drobo/Pictures/Image 1/Previews: No such file or directory

Anyway, I'm looking for any hints as to answers to my three areas of confusion above, and/or an easier way to accomplish the task. As I say, it's all working, so I'm just trying to understand what i'm seeing.

Thanks, this looks like a wonderful board.

1) Because in your example you are trying to delete the jpg files "recursively" using rm command & "." refers to current directory there is no way for "rm" to recursively delete the files you want if you use "." because it will search only current directory for "preview" & it won't search the subdirectories for "preview".
2) Try using "." with "-delete" flag. Let me know if it works.
3) The error is because after recursively deleting the files & directories "find" is not able to traverse back.
I hope this answer your queries.

1. Remove the double quotes around Previews. This works:

Code:

find . -type d -iname Previews -exec rm -R {} \;

2. Find's delete option will not delete a directory with files in it.

3. Suppress the error message by changing the rm options then send any find error messages to /dev/null:

Code:

find . -type d -iname Previews -exec rm -rf {} \; 2>/dev/null