[Solved] Print warning message if the running kernel is updated

landshark · 2023-03-31 02:52:04

Hi all,

I'm Stefan and I'm running the same Arch install for several years now (nice thing about Linux: plug the drive out of the old laptop and plug it in another one -> works).

It never occurred to me to register in this forum until now because I'm neater a newbie nor a pro. But now this has happened again...

My problem with pacman is that you cannot know by just casually looking at the output of pacman -Syu if you need to reboot. My laptop is suspended whenever I don't use it. Roughly 50 percent of my problems after an update result of me forgetting to reboot.

I was lazy so I asked ChatGPT about it and it came up with the following hook:

[Trigger]
Operation = Upgrade
Type = Package
Target = linux

[Action]
Description = Warn about kernel update
When = PostTransaction
Exec = /usr/bin/sh -c 'if pacman -Q linux | grep -q $(uname -r); then echo "WARNING: Kernel updated. Please reboot your system to ensure changes take effect."; fi'

Is it advisable to include such a hook (adding the possibility to infer the running kernel from uname) to the default install?

--
Cheers
Stefan

Last edited by landshark (2023-03-31 04:48:27)

schard · 2023-03-31 02:58:15

The Exec line is pure nonsense. It'll never output the warning.
Firstly the logic is inverted and secondly the version format of the package and uname never match due to a - vs . discrepancy.

130 ✗ srv ~ $ pacman -Q linux
linux 6.2.8.arch1-1
0 ✓ srv ~ $ uname -r
6.2.8-arch1-1

Furthermore the hook will just print another warning, i.e. noise during pacman's output.
I always consider rebooting the machine, when I see the initramfs being regenerated in the hooks.
No need for an additional message here.

Last edited by schard (2023-03-31 03:03:29)

Trilby · 2023-03-31 03:13:18

schard wrote:

I always consider rebooting the machine, when I see the initramfs being regenerated in the hooks.

Seconded. I don't personally have any need to reboot when a kernel is upgraded, but it's pretty damned hard to miss the initramfs rebuild. I'm not sure how one could miss than but still notice a single line warning message. If you watch pacman's output you should already be fine - if you don't watch it at all, then adding another message sure wont help.

Last edited by Trilby (2023-03-31 03:14:10)

landshark · 2023-03-31 04:47:18

schard wrote:

The Exec line is pure nonsense. It'll never output the warning.
Firstly the logic is inverted and secondly the version format of the package and uname never match due to a - vs . discrepancy.
130 ✗ srv ~ $ pacman -Q linux
linux 6.2.8.arch1-1
0 ✓ srv ~ $ uname -r
6.2.8-arch1-1

You are right, I missed that pacman has a dot and uname uses a hyphen ...

schard wrote:

Furthermore the hook will just print another warning, i.e. noise during pacman's output.
I always consider rebooting the machine, when I see the initramfs being regenerated in the hooks.
No need for an additional message here.

Trilby wrote:

if you don't watch it at all, then adding another message sure wont help

I see that maybe this is against the Arch way of doing things, but it got me serveral times where I was investigating problems which could be solved by a reboot.

But I get your hints, the truth is that I often don't look at the output of pacman after the update if there was no error. This is my problem and I will have a better look at the output in the future. Thanks for your replies

Trilby · 2023-03-31 12:49:29

Wanting to adjust every bit of your system to make it more useful for your own use is not at all against the "arch way" - if anything it's a pretty good example of it. But going through extra steps for no possible benefit (if you're not watching the output anyways) would be pretty silly.

In contrast, triggering an on-screen display (i.e., one of those popup notification things) or an email to you could make some sense for this use: if you miss the pacman output, you'd get a different indicator that you need to reboot. However, if you are not watching pacman output at all, you are really opening yourself up to lots of other problems.

Arch Linux

#1 2023-03-31 02:52:04

[Solved] Print warning message if the running kernel is updated

#2 2023-03-31 02:58:15

Re: [Solved] Print warning message if the running kernel is updated

#3 2023-03-31 03:13:18

Re: [Solved] Print warning message if the running kernel is updated

#4 2023-03-31 04:47:18

Re: [Solved] Print warning message if the running kernel is updated

#5 2023-03-31 12:49:29

Re: [Solved] Print warning message if the running kernel is updated

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