How can I copy files using the ansible.builtin.copy module and avoid conflicting file names?

I want files in the src directory to copy to the dest directory but I don't want the files with the same name to copy over. Does anyone know how I can do that?

- name: Copy files but not the ones that have the same name
  copy:
    src:  <src_dir>
    dest: <dest_dir>

Use the backup option of the copy module.

- copy:
    src: foo
    dest: /tmp/bar
    backup: true

This will create multiple files, of which, the one with the name specified in dest parameters will be the one representing the last run of Ansible.

For example:

$ ls -l /tmp/
total 12
-rw-r--r--   1 root   root   150 Mar 20 16:30 bar
-rw-r--r--   1 root   root   127 Mar 20 16:20 bar.249.2023-03-20@16:20:44~
-rw-r--r--   1 root   root   148 Mar 20 16:20 bar.329.2023-03-20@16:30:17~

Q: "Don't copy the files with the same name."

A: Set the parameter force to false. Quoting

> If false, the file will only be transferred if the destination does not exist.

    - copy:
        src: /tmp/test/src/
        dest: /tmp/test/dest/
        force: false

<hr>

<sup>

Example.

Given the files

shell> tree /tmp/test/
/tmp/test/
├── dest
│   └── a
└── src
    ├── a
    ├── b
    └── c

2 directories, 4 files

shell> cat /tmp/test/src/*
src
src
src

shell> cat /tmp/test/dest/*
dest

The playbook

- hosts: localhost
  tasks:
    - copy:
        src: /tmp/test/src/
        dest: /tmp/test/dest/
        force: false

will copy the files b and c only because the file a exists

shell> tree /tmp/test/
/tmp/test/
├── dest
│   ├── a
│   ├── b
│   └── c
└── src
    ├── a
    ├── b
    └── c

2 directories, 6 files

shell> cat /tmp/test/dest/*
dest
src
src

</sup>