Emacs by default allocates a pty for subprocesses. There’s no way to do this portably, as many Lisps don’t support it, so UIOP won’t help you here. If you’re on SBCL and portability is not a concern, you can use sb-ext:run-program with a :pty keyword argument, as described in section 7.7.3 of the SBCL manual. Failing that, it’s probably best to use sudo -S.

phoebe

On Jan 12, 2021, at 10:01 AM, Pierre Neidhardt <mail@ambrevar.xyz> wrote:

Hi!

I'd like to run a "sudo" command from Common Lisp.  The following works:

--8<---------------cut here---------------start------------->8---
(uiop:launch-program '("sudo" "-S" "ls" "/root") :input :stream :output *standard-output*)
(format (uiop:process-info-input #v1) "MY-PASSWORD~%")
(finish-output (uiop:process-info-input #v1))
--8<---------------cut here---------------end--------------->8---

Note that I'm using the "-S" parameter of sudo.  From the man page:

Write the prompt to the standard error and read the password
from the standard input instead of using the terminal device.

Without it, "sudo" terminate immediately.

Somehow, Emacs _does_ support calling the sudo process without the "-S"
flag.  Try this:

--8<---------------cut here---------------start------------->8---
(make-process :name "dummy" :command '("sudo" "ls" "/root"))
--8<---------------cut here---------------end--------------->8---

and the "sudo" process is kindly waiting for input in the background.

Any idea why that is?
Is it be possible to do the same in Common Lisp?

Cheers!

--
Pierre Neidhardt
https://ambrevar.xyz/