Kian Kasad:
Unable to open file: /dev/tty2: Operation not permitted.
Operating systems do a whole bunch of stuff when connecting user programs to terminals, including changing the permissions of the terminal device file to allow the logged-in user access. If you check the terminal device file of a terminal where you have actually logged in, you will find that it is owned by you, and that the device files of terminals where you have not logged in are owned by the superuser. This is one of several things that the login process does.
Taking ly's supplied systemd service unit and converting it using the nosh toolset's convert-systemd-units command (http://jdebp.uk./Softwares/nosh/guide/commands/convert-systemd-units.xml), one obtains the following, which demonstrates that there are extra steps involved and provides at least a pointer to how a "run" script for a runit service should be constructed.
% convert-systemd-units --no-systemd-quirks ./ly.service convert-systemd-units: WARNING: ./ly.service: Unused setting: [install] alias = display-manager.service % % system-control print-service-scripts ./ly start:#!/bin/nosh start:#Start file generated from ./ly.service start:true stop:#!/bin/nosh stop:#Stop file generated from ./ly.service stop:true run:#!/bin/nosh run:#Run file generated from ./ly.service run:#TUI display manager run:vc-get-tty /dev/tty2 run:open-controlling-tty --revoke run:vc-reset-tty --hard-reset run:/usr/bin/ly restart:#!/bin/sh restart:#Restart file generated from ./ly.service restart:exec true # ignore script arguments %
Notice how the service invokes the open-controlling-tty program (http://jdebp.uk./Softwares/nosh/guide/commands/open-controlling-tty.xml) to open the terminal device file as standard I/O and to make it the service's controlling terminal. It knows what terminal device because that has been set up by the vc-get-tty program (http://jdebp.uk./Softwares/nosh/guide/commands/vc-get-tty.xml) which was passed the name "/dev/tty2".
Notice also how the service runs the "ly" program as the superuser. It does not drop privileges by switching to an unprivileged account.
Furthermore, notice that there are two separate places where one tells "ly" what terminal to use: in the service definition, as here, and in the program's own configuration file.
