How to move all files with a certain file extension from subdirectories to a single directory

Question

I have a directory that contains many subdirectories. The subdirectories contain lots of types of files with different file extensions. I want to move (not copy) all the files of one type into a new directory. I need all these files to be in the same directory, i.e. it needs to be flat.

(My use case is that I want to move ebooks called *.epub from many directories into a single folder that an EPUB reader can find.)

Answer 1

In zsh, you can use a recursive glob:

mkdir ~/epubs
mv -- **/*.epub ~/epubs/

In bash ≥4, run shopt -s globstar (you can put this in your ~/.bashrc) then the command above. In ksh, run set -o globstar first.

With only POSIX tools, run find:

find . -name '*.epub' -exec mv {} ~/epubs \;

Answer 2

Try doing this :

mkdir ../new_dir
find . -type f -name '*.epub' -exec mv {} ../new_dir/ \;

if all the files are named name.epub, then you need to increment a variable like this (using bash )

mkdir ../new_dir
find . -type f -name '*.epub' |
    while read a; do
        ((c++))
        base="${a##*/}"
        mv "$a" "../new_dir/${base%.epub}_$(printf %.03d $c).epub"
    done

Answer 3

Using bash under Linux:

shopt -s nullglob globstar
mv -t ~/epub_directory ~/big_dir/**/*.epub