Custom screen lock `i3lock` command not working as expected

Question

Custom screen lock `i3lock` command not working as expected

thomasheartman opened this issue 3 years ago · comments

Hey,

I was playing around with screen locking for my system and desktop environment and tried setting i3lock as the desktop-environment-screenlock-command, but it doesn't work properly. Rather than locking the screen, it simply flashes and then nothing happens. I tried with a xscreensaver-command previously and that worked just fine. Is there an output buffer or anything that I can check to see what's going on? Running the command manually from the shell works just fine.

Do you know what might be going on or how I can trouble shoot this? I'm happy to provide more info if you let me know what you need.

Thanks!

Damien Cassou · Answer 1 · Thu Feb 11 2021 03:17:35 GMT+0800 (China Standard Time)

Hi @thomasheartman,

there is no buffer attached to this command. You can easily change that by adding this to your init file:

(defun desktop-environment-lock-screen ()
  (interactive)
  (start-process-shell-command "lock" "*desktop-environment-lock-screen*" desktop-environment-screenlock-command))

After you evaluate expression or restart Emacs, the content of the *desktop-environment-lock-screen* buffer will be populated with messages when you lock your screen.

Thomas Heartman · Answer 2 · Thu Feb 11 2021 18:29:04 GMT+0800 (China Standard Time)

Thanks!

All the output I get is:

Process lock finished

So that's not much to go off. However, If I use shell-command instead, it works:

(defun desktop-environment-lock-screen ()
  (interactive)
  (shell-command desktop-environment-screenlock-command))

I'm not sure what's going on or why start-process-shell-command isn't working as expected. The function docs don't really make it much clearer either. Do you have any idea what's going on?

Damien Cassou · Answer 3 · Sat Feb 20 2021 21:59:40 GMT+0800 (China Standard Time)

I've just had a look as well and don't understand the differences between the 2 functions either. If shell-command works better for you, I would accept a PR changing that.

Thomas Heartman · Answer 4 · Sun Feb 21 2021 22:05:56 GMT+0800 (China Standard Time)

Sure thing! I can do that. I had a little look through the code now; seems start-process-shell-command is used by three functions (screenshot, screenshot-part, and lock-screen). Would you want me to update the other uses of start-process-shell-command too (for consistency across the package) or leave them as is (to avoid potentially breaking something else)?

Damien Cassou · Answer 5 · Mon Feb 22 2021 15:11:18 GMT+0800 (China Standard Time)

Thomas Heartman <notifications@github.com> writes:

Would you want me to update the other uses of `start-process-shell-command` too (for consistency across the package) or leave them as is (to avoid potentially breaking something else)?

Please update all of them if it works for you.

…

-- Damien Cassou "Success is the ability to go from one failure to another without losing enthusiasm." --Winston Churchill

Damien Cassou · Answer 6 · Mon Mar 08 2021 00:29:59 GMT+0800 (China Standard Time)

As explained in #24 (comment), the solution is to pass --nofork to i3lock.