隐藏父文件夹中所有子文件夹的列表，但显示子文件夹的内容

Hide listing of all childfolders in parent folder but show childfolder's content, or simply writing something like below in the .htaccess of parent folder...

IndexIgnore * (except childfolders+their content)

Directory structure:

parent >

child 1->something.pdf
child 2->anything.pdf
...
...
child n->another-something.pdf

now to the user when he goes to parent, then nothing should be visible but when he goes to parent/child [1 to n]/ he should see the corresponding pdf.

(also childfolders are dynamically generated and are very large in number !)

Place this code in parent/.htaccess:

RewriteEngine on

RewriteRule ^$ - [F]