fish: Add fish-systemctl

https://github.com/wawa19933/fish-systemd

We do not use any plugin manager so just add this manually.

fish/.config/fish/conf.d/systemd-abbr.fish

@@ -0,0 +1,4 @@
+abbr -a -g sc systemctl
+abbr -a -g scu systemctl --user
+abbr -a -g jr journalctl
+abbr -a -g jru journalctl --user

fish/.config/fish/functions/systemctl.fish

@@ -0,0 +1,21 @@
+function systemctl --description 'Wraps privileged and user systemctl commands to use sudo when necessary' -w systemctl
+    set -l user_commands \
+        list-units list-unit-files list-jobs list-timers \
+        list-sockets list-dependencies list-machines \
+        is-active is-enabled is-failed \
+        status show help get-default show-environment cat
+
+    set -l root_commands start stop reload restart try-restart \
+        reload-or-restart try-reload-or-restart isolate kill clean \
+        set-property reset-failed enable disable reenable preset \
+        preset-all mask unmask link revert add-wants add-requires \
+        edit set-default cancel set-environment unset-environment import-environment \
+        daemon-reload daemon-reexec default rescue emergency halt poweroff reboot \
+        kexec exit switch-root suspend hibernate hybrid-sleep suspend-then-hibernate
+
+    if contains -- --user $argv; or not contains -- $argv[1] $root_commands
+        command systemctl $argv
+    else
+        command sudo systemctl $argv
+    end
+end