recursively move types of files

[Charles L. Snyder]

Hi

I have 2 separate but file management - related questions (emacs
22.2.1, mac leopard system):

1. I want to move all .pdb files from a folder (and all its
subfolders):

/Users/cls/ebooks

to another folder:
 /Users/cls/pdb_files

I can find all the files with Alt-x find-dired RET ~/ebooks RET -name
"*.pdb" RET
but how do I mark and move the files within emacs?

2. I have a huge number of files named like this
"Report_work_01232008_blah.pdf", and I want to replace all the "_"
with " "
ie., "Report work 01232008 blah.pdf"
Some files have one underscore, some have many more.

When I Crtl-x d to the folder, and mark all files containing (% g RET
_ ) an underscore, there are several problems:

- it doesn't search and mark files in the the subdirectories / nested
folders

- only the first underscored in the filename is changed, not all of
them  (how do I fix the regex for "_")

- I sometimes get a 'maximum buffer size exceeded'.

Thanks in advance

cls