How to move some specific folder keeping a predefined directory structure?

Question

I have a directory containing about 7k folders. These folders were extracted from zips and some of the extraction was done using Python scripts. Some of these folders are extracted in such a way that

             Main Dir
                |
         ---------------
        |               |
      fold1            fold2
        |               |
      ------         -------
    |        |          |
  .pngs   .txts       fold2
                        |
                     -------
                    |       |
                  .pngs    .txts

The requirement is to move the fold2 category of folders in a directory structure similar to that of fold1 where a folder contains the data instead of another same named folder containing the data.

How may I do it using bash or command line so that I have all 7k folders in a homogeneous structure similar to fold1?

Answer 1

The following script will search the current working directory for paths of the form a/B/B/c and compress them to a/B/c. This also compresses a/B/B/B/B/c to a/B/c and a/B/B/c/D/D/e to a/B/c/D/e.

You need GNU find to use the -regextype option and an implementation of mv supporting -n. If you don't have these please have a look at the unsafe posix version at the end of the script.

shopt -s dotglob failglob
find . -depth -regextype egrep -type d -regex '.*/([^/]*)/\1' -print0 |
while IFS= read -r -d '' path; do
  mv -n -t "$path/.." "$path"/* &&
  rmdir "$path"
done

Arbitrary path names (whitespaces, special symbols like *, and even linebreaks) are supported.

The command makes sure not to overwrite or delete any files. In a situation as in the left tree the repeated sub-directory has to be kept. You will get the error message rmdir: failed to remove './A/A'. The result can be seen to the right.

. (before)               . (after)
└── A                    └── A
    ├── someFile             ├── someFile
    ├── collision            ├── collision
    └── A                    ├── anotherFile
        ├── collision        └── A
        └── anotherFile          └── collision

Hidden files are copied too.

Bad Posix Version

A more portable version of the script which cannot handle line breaks inside paths, may overwrite files in situations as the one shown above, and cannot move hidden files (sub-directory is kept if there are hidden files inside).

find . -depth -type d | grep -E -x '.*/([^/]*)/\1' |
while IFS= read -r path; do
  mv "$path"/* "$path/.." &&
  rmdir "$path"
done

Answer 2

Not sure if it's what you need but...

mv /maindir/fold2/ /maindir/renamed/
mv /maindir/renamed/fold2/ /maindir/fold2/

then, renamed should be empty, delete it.

or this should do the job too

mv maindir/fold2/fold2/{*,.*} maindir/fold2/

then /maindir/fold2/fold2/ should be empty