How can I pass registered variable as array in Ansible?

Question

I am trying to list the files in a directory and copy to some other directory.

This is my playbook:

---
- hosts: testserver
  become: true
  tasks:
  - name: list files
    command: " ls /root/"
    register: r
  - debug: var=r

  - debug: msg="item.item={{item.item}}, item.stdout={{item.stdout}}, item.changed={{item.changed}}"
    with_items: "{{r.results}}"

This is the error I am getting:

FAILED! => {"msg": "'dict object' has no attribute 'results'"}

Answer 1

You have a debug task there that shows you the contents of the variable r. Do you see a key named results?

You only see the results key (and need to use item.item) when are have registered values in a loop, as described here. You're not doing that, so the structure of r will be much simpler.

If you're trying to iterate over the lines of the ls output, you probably want:

- debug: 
    msg: "filename={{item}}"
  with_items: "{{r.stdout_lines}}"

Answer 2

I am trying to list the files in a directory and copy to some other directory.

1. Don't parse ls output! Neither in Ansible, nor anywhere else.

2. Don't use command module for what Ansible offers a native one.

Ansible has a find module which returns a list of files. In your case:

- name: list files
  find:
    paths: /root
  register: my_find

- debug:
    var: item.path
  with_items: "{{ my_find.files }}"