When cleaning up a bit on my computer, I wanted to flatten a directory structure. Not wanting to move everything by hand, I searched for a way to automate it. On macOS and Linux, there is a command find that lets you find files deeply nested.
Moving files
The command above finds all nested files with at least one directory down and then passes the arguments to the move mv command. Here the /path/to/directory directory is the directory we want to flatten.
find /path/to/directory -mindepth 2 -type f -exec mv '{}' /path/to/directory \;
With -type f, we only find files in the given directory where we want it to look at least from a depth of two. The move will overwrite files with the same name. To control which one to overwrite or not, add -i to the mv command to interactively approve overwrites or -f to force overwrites.
Example
/path/to/directory
|-- subdir1/
| |-- subsubdir1/
| | |-- file1.txt
| | |-- file2.txt
| |-- subsubdir2/
| |-- file3.txt
|-- subdir2/
|-- file4.txt
|-- subsubdir3/
|-- file5.txt
|-- file6.txt
After running the command, the directory will look like this:
/path/to/directory
|-- subdir1/
| |-- subsubdir1/
| |-- subsubdir2/
|-- subdir2/
| |-- subsubdir3/
|-- file1.txt
|-- file2.txt
|-- file3.txt
|-- file4.txt
|-- file5.txt
|-- file6.txt
Cleaning up
After moving, I still had a lot of empty directories. Deleting them by hand would be little work, but what if I could also automate it? We can use the find command again to remove all directories using -delete. With -empty, we ensure that we do not delete non-empty directories when something goes wrong. The command also needs the -depth and -mindepth 1 flags to recursively find the deepest directories first, as there are possible subdirectories in it and thus not empty.
find /path/to/directory -type d -depth -mindepth 1 -empty -delete
It will give us a directory with all files in the root and no subdirectories.
/path/to/directory
|-- file1.txt
|-- file2.txt
|-- file3.txt
|-- file4.txt
|-- file5.txt
|-- file6.txt
Combining both
We can combine both commands to flatten a directory and clean it up in succession. The following command is a combination of both steps at once. Using -o means that find will only execute the second command if the first fails.
find /path/to/directory -mindepth 2 -type f -exec mv '{}' /path/to/directory \; \
-o -type d -depth -mindepth 1 -empty -delete