Question: Can you show/list all extended-attributes and how?

Answer: 
In Linux, independent of filesystem command to view file extended attributes is

```
getfattr -d -m ".*" <filename>

```

At last it show Selinux attributes.

```
getfattr -d <filename>

```

Show only user.\* attributes.
On a MacOs the Unix flavor is Darwin which is derived from BSD. In this version of Unix, use the command `xattr` to list (or create, write, or clear) the extended attributes.

`xattr <filename>` will just list the names of the attributes

`xattr -l <filename>` will list their names and values

`xattr -h` for a more succinct help message

`man xattr` for a detailed help message (`ZZ` to exit the help)

I found this command at <https://en.wikipedia.org/wiki/Extended_file_attributes#macOS>