I try to create a user-defined command in vim that is supposed to return an uuid.
command -range CreateUUID !python3 -c 'import uuid; print(uuid.uuid4())'<cr>
The command works but it just outputs to the terminal.
I have tried
In VimScript commands never return anything, as they are not even considered as expressions. You must declare a function instead. For example,
function! UUID() abort
python3 import uuid
return py3eval('str(uuid.uuid4())')
endfunction
:put =UUID()
An alternative is to capture the command's output by using a specialized function like execute() (for an Ex command) or system() (for an external tool):
:put =system('uuidgen')
Yet another thing is "read-space-bang" command (:h :r!), so you can do
:r !python3 -c 'import uuid; print(uuid.uuid4())'
But, 1) again, it only inserts an external tool's stdout, not an Ex-command's output; 2) it's not the way to compose two arbitrary Ex-commands, as "read-space-bang" counts as a single command with a very unique syntax.
