You will likely have to adapt your scripts for OS-specific or installation-specific tasks like package management and modifying filesystems. In the past I've us

You will likely have to adapt your scripts for OS-specific or installation-specific tasks like package management and modifying filesystems. In the past I've used Nix (either via `nix run` and `nix shell` or templating in Nixpkgs' `writeScript` or similar) for this stuff to guarantee that I'm always running the same tools regardless of what's installed on the base system. This can free you up to use a different shell, rely on recent features of Bash, use GNUisms in coreutils, sed, grep, find, etc., fix a specific version of jq, use external templating tools, etc. For systemd-based distros, you can even use Nix to manually install system-wide services: just install a package to the default or system profile, and then symlink the included unit files from the profile (not the direct store path) into /etc/systemd. `systemctl daemon-reload` and you can manipulate them in all the usual ways one would with systemd. Other Unix distros don't have first-class support with Nix so you may need to take some additional care when working out your script (especially the part of it that installs Nix), but if you don't need to set up services this way you can write portable scripts with few limitations that will work across all Linux distros, macOS, probably FreeBSD and maybe NetBSD. I've never been so lucky as to work at a place that used any Unix flavors other than Linux and macOS, though.