Selective Merge Directories

selective-merge-directories.sh

#!/bin/bash

BASE_DIR='/home/base'
PRIMARY_DIR='/home/primary'
SECONDARY_DIR='/home/secondary'

mkdir -p ${BASE_DIR}
pushd ${BASE_DIR}
find ${PRIMARY_DIR} -type d | cut -d '/' -f 7- | grep '/' | while read nested_directory; do
    mkdir -p ${nested_directory}
    pushd ${nested_directory}
        find ${PRIMARY_DIR}/${nested_directory} -type f -exec ln -s {} . \;
        find ${SECONDARY_DIR}/${nested_directory} -type f -exec ln -s {} . \;
    popd
done
find ${PRIMARY_DIR} -type d | cut -d '/' -f 7- | grep '/' | while read nested_directory; do
    pushd ${nested_directory}
        ls -1 * | wc -l
    popd
done