Copy folders to another set of directories, only if folders already exist

Question

I want to copy (overwrite) folders from one directory to another set of directories, only if the folders in directory1 exist in directory2.

For example, I have stored some folders in my home directory:

home
    |admin
        |updates
            |package1
            |package2
            |package3

I also have another folder with builds of an app:

home
    |builds
        |build1
            |packages
                |package1
                |package2
                |package3
        |build2
            |packages
                |package1
                |package3
        |build3
            |rev1
                |packages
                    |package1
            |rev2
                |packages
                    |package2

I want the 'package1', 'package2', 'package3' folders found in '/home/updates/package' directory to be copied over to the 'packages' folders found recursively in '/home/builds' directory, but only if the folders already exist.

So in the example above, 'package1'/'package2'/'package3' would be copied into '/home/builds/build1/packages'. Only 'package1' would be copied into '/home/builds/build3/rev1/packages' ('package2'/'package3' would not because it doesn't exist there).

In addition, 'build1'/'build2'/'build3' may have different owner/group permissions so I would like to retain the relative target directory's permissions.

Answer 1

mkdir -p test/updates/pack1
...
mkdir -p test/builds/builds1/packages/pack3
...
touch test/updates/pack1/f1-1
...

run this command

find test/builds -type d  -name packages -exec bash -c 'for pk in "$1"/pack* ; do cp -r test/updates/"${pk##*/}" $1 ; done' none {} \;

• 'find' will search recursively for "packages" directories.
• '-exec bash -c' will run a batch with the result of 'find'.
• The bash 'for' loop will search for existing "packX" in the destination and copy them from source (using param. extensions) to the destination.

Greetings

Answer 2

for i in package1 package2 package3; do find /home/ -name $i -type d -not -path "/home/admin/updates/$i" -exec cp /home/admin/updates/$i/* {} \;; done

• for i in package1 package2 package3; ... ; done - iterate through the names of the folders

• find /home/ -name $i -type d - recursively find all the folders with said names in the /home/ directory

• -not -path "/home/admin/updates/$i" - exclude from find results the original directory

• -exec cp /home/admin/updates/$i/* {} \; - execute the command - copy files from original folder to found folder