Thanks LuckyCyborg, dugan,
so I think it's clear, and hereby explicitly "documented", that no such thing exists. That's probably in the spirit of Slackware.
If you came here searching for iptables symlinks:
Code:
#!/bin/sh
# switch iptables to "nft" backend, default is "legacy" backend
cd /usr/sbin
ln -sf xtables-nft-multi iptables-save
ln -sf xtables-nft-multi iptables-restore
ln -sf xtables-nft-multi iptables
ln -sf xtables-nft-multi ip6tables-save
ln -sf xtables-nft-multi ip6tables-restore
ln -sf xtables-nft-multi ip6tables
A word of caution. Even when there is no update-alternatives/eselect-workalike, the links may be silently undone when updating the iptables package. So I keep the script around, and maybe it should be run in certain situations, e.g. before running iptables commands.
Of course one could also write wrapper scripts and functions, and call iptables-nft directly from there. Note it seems docker and maybe other things call the iptables binary (whatever the link points to), so making the links makes sense.
drumz, why should one know about it, and why should anyone care?
First, because if you do these "ln -sf" commands, and something else wants to control these links, your work will soon be undone.
Second, imagine you do this on debian (just an example), not knowing about update-alternatives. And you open threads in a forum, trying to discuss your topic. If you get caught doing something "wrong" like that, the topic will certainly change ... For this, it is better to do things "right" to begin with.
What is update-alternatives/eselect?
So I think the more "full featured" distributions assume that /usr, /bin, /sbin, parts of /var and some other things are not for the user/admin to deal with, except for certain interfaces that have the distribution's blessing. For this, there are these tools that select default compiler versions (gcc, rust, llvm ...), select symlink targets for vi, iptables, others, select graphics related drivers and backends, and whatever. Just "eselect" in Gentoo, "update-alternatives --get-selections" shows more information about it. I'm sure Redhat, MX, Manjaro, Mint, Suse, Arch, deepin etc. have similar tools. Some more minimal ones might not.