bash

bash-3.2$ mkdir a
bash-3.2$ mkdir b
bash-3.2$ mkdir a/a1
bash-3.2$ mkdir a/a2
bash-3.2$ mkdir a/a3
bash-3.2$ touch a/a1/f1
bash-3.2$ touch a/a1/f2
bash-3.2$ touch a/a1/f3
bash-3.2$ touch a/a2/f1
bash-3.2$ touch a/a2/f2
bash-3.2$ touch a/a2/f3
bash-3.2$ touch a/a3/f1
bash-3.2$ touch a/a3/f2
bash-3.2$ touch a/a3/f3
bash-3.2$ cp -r a/* b/
bash-3.2$ ls b
a1	a2	a3

eshell

/tmp/test $ mkdir a
/tmp/test $ mkdir b
/tmp/test $ mkdir a/a1
/tmp/test $ mkdir a/a2
/tmp/test $ mkdir a/a3
/tmp/test $ touch a/a1/f1
/tmp/test $ touch a/a1/f2
/tmp/test $ touch a/a1/f3
/tmp/test $ touch a/a2/f1
/tmp/test $ touch a/a2/f2
/tmp/test $ touch a/a2/f3
/tmp/test $ touch a/a3/f1
/tmp/test $ touch a/a3/f2
/tmp/test $ touch a/a3/f3
/tmp/test $ cp -r a/* b/
/tmp/test $ ls b
f1  f2  f3