Better way of symlinking up to update (rpm)

[AntonVanAssche]

Rpm-packages have a %preun stage this stage contains the commands that are run after uninstalling the package. This is something similar the postrm file for deb-packages.

This allows you to let the package manager remove the symlink, this makes it so you don't have to write extra code to remove it inside the install script.

You can find more information about it here https://www.golinuxhub.com/2018/05/how-to-execute-script-at-pre-post-preun-postun-spec-file-rpm/.

[Crilum]

So wait, this makes a symlink after installation?? This is exactly what I have been looking for (you can tell from all the failed update2deb action runs, lol 🤣)!

[Crilum]

So I've run into a problem. This works, except when you already have a /usr/bin/up file... So, do you think it would be a good idea to force the symlink? I would, except if somebody has an important /usr/bin/up file, they're probably not going to be happy when it gets overwritten... I suppose another way to fix this would be to use a pre-install scriptlet that removes the /usr/bin/up file, but then we might as well force the symlink....

Thoughts?

[AntonVanAssche]

do you think it would be a good idea to force the symlink?

No, there is always a possibility that the user has a program/script that invokes /usr/bin/up. Therefore if a file /usr/bin/up already exists I would not create the symlink.

I think you could do something like below, but with the correct variables in the spec file. Althought I'm not 100% sure it will work.

[[ $(ls -l $(command -v up)) =~ "/usr/bin/update" ]] || ln -v -s /usr/bin/update "/usr/bin/up"

This will execute ls -l /path/to/up and then use regex to see if it contains the string /usr/bin/update. If true it will not symlink.

What do you think is best?

[Crilum]

Oh that's smart! I'll test that.

[AntonVanAssche]

Oh that's smart! I'll test that.

Keep in mind that this is probably not the most performant way of doing it.

[Crilum]

Another way would be to add an alias to the .bashrc file, but the way you suggested does work..

[AntonVanAssche]

Another way would be to add an alias to the .bashrc file

I don't really recommend this as some users may already have an alias up that updates the system (like sudo dnf update) or something else.

I would do something like I showed above (#19 (comment)), and then let the user make the choice if they want an alias or a symlink.

[Crilum]

I wasn't really going to do the alias thing, but I was just putting it out there.

[AntonVanAssche]

Oh okay, my bad 😅!

[Crilum]

Thanks for the code!

[AntonVanAssche]

You're welcome!

[AntonVanAssche]

BTW you've updated the version inside the spec file by accident (86731f0).

[Crilum]

BTW you've updated the version inside the spec file by accident (86731f0).

Oh, thanks... I didn't realize I did that 😆