website: BEL

website/app/vt/bel/page.mdx

@@ -0,0 +1,26 @@
+import VTSequence from "@/components/VTSequence";
+
+# Bell (BEL)
+
+<VTSequence sequence="BEL" />
+
+The purpose of the bell sequence is to raise the attention
+of the user. Historically, this would [ring a physical bell](https://en.wikipedia.org/wiki/Bell_character). Today, many alternate behaviors are
+acceptable:
+
+- An audible sound can be played through the speakers
+- Background or border of a window can visually flash
+- The terminal window can come into focus or be put on top
+- Application icon can bounce or otherwise draw attention
+- A desktop notification can be shown
+
+Normally, the bell behavior is configurable and can be disabled.
+
+## BEL as an OSC Terminator
+
+The `BEL` character is also a valid terminating character for
+OSC sequences, although `ST` is preferred. If `BEL` is the
+terminating character for an OSC sequence, any responses should
+also terminate with the `BEL` character.[^1]
+
+[^1]: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html

website/components/VTSequence.tsx

@@ -1,8 +1,12 @@
+// Draw a diagram showing the VT sequence.
 export default function VTSequence({ sequence }: { sequence: string }) {
+  const specialChar = special[sequence] ?? 0;
+  const hex = specialChar.toString(16).padStart(2, "0");
+
   return (
     <div className="flex my-2.5">
       <div className="border shrink px-1 grid grid-rows-2 grid-cols-1 text-center">
-        <div>0x08</div>
+        <div>0x{hex}</div>
         <div>{sequence}</div>
       </div>
     </div>
@@ -10,5 +14,6 @@ export default function VTSequence({ sequence }: { sequence: string }) {
 }
 
 const special = {
+  BEL: 0x07,
   BS: 0x08,
 };

website/next.config.mjs

@@ -21,7 +21,6 @@ const withMDX = createMDX({
   // Add markdown plugins here, as desired
   options: {
     remarkPlugins: [remarkGfm, remarkToc],
-
     rehypePlugins: [rehypeSlug, [rehypePrettyCode, prettyCodeOptions]],
   },
 });

website/package.json

@@ -18,7 +18,7 @@
     "react-dom": "^18",
     "rehype-pretty-code": "^0.10.1",
     "rehype-slug": "^6.0.0",
-    "remark-gfm": "^4.0.0",
+    "remark-gfm": "^3.0.1",
     "remark-toc": "^9.0.0",
     "shiki": "^0.14.4"
   },