Add update-packages-list script.

update-packages-list

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# Check for an /etc/os-release.
+[[ ! -e /etc/os-release ]] && {
+  printf "%s: %s\\n" "${BASH_SOURCE[0]}" "No /etc/os-release to determine system." >&2
+  exit 1
+}
+
+# Source system info.
+. /etc/os-release
+
+# Create package list depending on system type.
+case "$ID" in
+  'slackware')
+    /usr/sbin/slackpkg -batch=on -default_answer=y generate-template "$(hostname --short)" >/dev/null
+    ;;
+  'void')
+    /usr/sbin/xbps-query -l | awk '{ print $2 }' | rev | cut -d- -f2- | rev >/etc/pkglist
+    ;;
+  *)
+    printf "%s: %s\\n" "${BASH_SOURCE[0]}" "Unsupported system." >&2
+    exit 1
+    ;;
+esac
+
+exit 0