From 4a9214d09d6a526bd029a1f92a01a5f451313c9a Mon Sep 17 00:00:00 2001
From: johannst <johannst@users.noreply.github.com>
Date: Wed, 9 Apr 2025 22:28:27 +0000
Subject: deploy: 773d9b46ee3b1b88a94e69f42ea42654c63c48ec

---
 linux/acl.html          | 19 +++++++++++--------
 linux/coredump.html     | 19 +++++++++++--------
 linux/cpufreq.html      | 19 +++++++++++--------
 linux/cryptsetup.html   | 19 +++++++++++--------
 linux/cups.html         | 22 ++++++++++++++--------
 linux/index.html        | 19 +++++++++++--------
 linux/input.html        | 19 +++++++++++--------
 linux/ptrace_scope.html | 19 +++++++++++--------
 linux/swap.html         | 19 +++++++++++--------
 linux/systemd.html      | 19 +++++++++++--------
 linux/zfs.html          | 19 +++++++++++--------
 11 files changed, 124 insertions(+), 88 deletions(-)

(limited to 'linux')

diff --git a/linux/acl.html b/linux/acl.html
index d782048..9c1d6ee 100644
--- a/linux/acl.html
+++ b/linux/acl.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/coredump.html b/linux/coredump.html
index 7e06ef9..c99c004 100644
--- a/linux/coredump.html
+++ b/linux/coredump.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/cpufreq.html b/linux/cpufreq.html
index bc4fca5..06cd491 100644
--- a/linux/cpufreq.html
+++ b/linux/cpufreq.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/cryptsetup.html b/linux/cryptsetup.html
index a4be45d..35e70f2 100644
--- a/linux/cryptsetup.html
+++ b/linux/cryptsetup.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/cups.html b/linux/cups.html
index c180230..8564cd3 100644
--- a/linux/cups.html
+++ b/linux/cups.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
@@ -206,6 +209,9 @@ lp -d PRINTER FILE
     -o sides=one-sided               print front-page only
     -o sides=two-sided-long-edge     print duplex
 
+# Show job queue
+lpq -P PRINTER
+
 # Remove pending print job.
 lprm JOOBID
 </code></pre>
diff --git a/linux/index.html b/linux/index.html
index 4870c12..14dd1ca 100644
--- a/linux/index.html
+++ b/linux/index.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/input.html b/linux/input.html
index a87a995..3f4dced 100644
--- a/linux/input.html
+++ b/linux/input.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/ptrace_scope.html b/linux/ptrace_scope.html
index 027b6ee..8cf7664 100644
--- a/linux/ptrace_scope.html
+++ b/linux/ptrace_scope.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/swap.html b/linux/swap.html
index 48ae24b..734a4b4 100644
--- a/linux/swap.html
+++ b/linux/swap.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/systemd.html b/linux/systemd.html
index b5f6dd7..80ef097 100644
--- a/linux/systemd.html
+++ b/linux/systemd.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
diff --git a/linux/zfs.html b/linux/zfs.html
index 21597af..26162d9 100644
--- a/linux/zfs.html
+++ b/linux/zfs.html
@@ -31,10 +31,11 @@
         <!-- Custom theme stylesheets -->
 
 
-        <!-- Provide site root to javascript -->
+        <!-- Provide site root and default themes to javascript -->
         <script>
-            var path_to_root = "../";
-            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
+            const path_to_root = "../";
+            const default_light_theme = "light";
+            const default_dark_theme = "navy";
         </script>
         <!-- Start loading toc.js asap -->
         <script src="../toc.js"></script>
@@ -44,8 +45,8 @@
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
-                var theme = localStorage.getItem('mdbook-theme');
-                var sidebar = localStorage.getItem('mdbook-sidebar');
+                let theme = localStorage.getItem('mdbook-theme');
+                let sidebar = localStorage.getItem('mdbook-sidebar');
 
                 if (theme.startsWith('"') && theme.endsWith('"')) {
                     localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
@@ -59,7 +60,8 @@
 
         <!-- Set the theme before any content is loaded, prevents flash -->
         <script>
-            var theme;
+            const default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? default_dark_theme : default_light_theme;
+            let theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
             const html = document.documentElement;
@@ -72,8 +74,8 @@
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var sidebar = null;
-            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
+            let sidebar = null;
+            const sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
@@ -109,6 +111,7 @@
                             <i class="fa fa-paint-brush"></i>
                         </button>
                         <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="default_theme">Auto</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                             <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
-- 
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