Title the panel with the machine's pretty name

Read PRETTY_HOSTNAME from /etc/machine-info, falling back to NAME from
/etc/os-release. The name stays on the machine rather than in the repo.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 34 insertions, 7 deletions

diff --git a/README.md b/README.md
index 104863d..fd7a6c4 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,12 @@ assembles the complete theme in `dist/udt/`: `theme.txt`, the PNG slices in
 the same colours, the `.pf2` fonts and `background.jpg`, a GRUB-readable copy
 of `~/.cache/udt/wpaper`. Both outputs are gitignored.
 
+The panel title is the machine's pretty name, `PRETTY_HOSTNAME` in
+`/etc/machine-info`, or the OS name from `/etc/os-release` when that is not
+set. To set it, as root:
+
+    echo 'PRETTY_HOSTNAME="My Machine"' > /etc/machine-info
+
 The accent is the scheme's fixed `accent` role, not the wallpaper-tracking
 one: nothing at boot can read that.
 
diff --git a/build b/build
index 5e14ce0..5397388 100755
--- a/build
+++ b/build
@@ -13,6 +13,7 @@ dist/udt/ untouched. Never touches /boot: root copies dist/udt/ there.
 """
 import os
 import re
+import shlex
 import shutil
 import struct
 import subprocess
@@ -132,15 +133,27 @@ def font(fname, pattern, size, name):
     return cached
 
 
-def os_name():
-    for line in Path("/etc/os-release").read_text().splitlines():
-        if line.startswith("NAME="):
-            return line[5:].strip('"')
-    return "GNU/Linux"
+def shell_var(path, key):
+    """KEY's value from a KEY="value" file (machine-info, os-release), or None."""
+    try:
+        lines = Path(path).read_text().splitlines()
+    except FileNotFoundError:
+        return None
+    for line in lines:
+        if line.startswith(f"{key}="):
+            return " ".join(shlex.split(line[len(key) + 1:])) or None
+    return None
+
+
+def title():
+    """The machine's pretty name if root has set one, else the OS name."""
+    name = (shell_var("/etc/machine-info", "PRETTY_HOSTNAME")
+            or shell_var("/etc/os-release", "NAME") or "GNU/Linux")
+    return name.replace('"', "'")  # it lands inside a quoted theme.txt string
 
 
 def assemble(stage, text, c, wallpaper, fonts):
-    (stage / "theme.txt").write_text(text.replace("%TITLE%", os_name()))
+    (stage / "theme.txt").write_text(text.replace("%TITLE%", title()))
     slices = {
         "panel.png": (8, 8, (*c["bg_alt"], PANEL_ALPHA)),
         # The selected item: a 4px accent bar on the left, surface behind.
@@ -183,6 +196,13 @@ def selftest():
     assert set(re.findall(r"@[A-Z_]+@", tpl)) <= PLACEHOLDERS, "template token udt does not fill"
     for _, _, name in FONTS.values():
         assert f'"{name}"' in tpl, f"template does not use font {name}"
+    with tempfile.NamedTemporaryFile("w") as f:
+        f.write('PRETTY_HOSTNAME="A B\'s C"\nEMPTY=\n')
+        f.flush()
+        assert shell_var(f.name, "PRETTY_HOSTNAME") == "A B's C"
+        assert shell_var(f.name, "EMPTY") is None
+        assert shell_var(f.name, "MISSING") is None
+    assert shell_var("/nonexistent", "X") is None
     print("selftest ok")
 
 
diff --git a/theme.txt.in b/theme.txt.in
index 173077d..e327445 100644
--- a/theme.txt.in
+++ b/theme.txt.in
@@ -18,7 +18,8 @@ terminal-width: "100%"
 terminal-height: "100%"
 terminal-border: "0"
 
-# %TITLE% is filled in by ./build from /etc/os-release.
+# %TITLE% is filled in by ./build: PRETTY_HOSTNAME from /etc/machine-info,
+# else NAME from /etc/os-release.
 + label {
   left = 3%
   top = 8%