A root commands file lists every builtin, its argument and which ctl takes it

A script could learn the builtin words only from source or the Help
window. /commands is generated from the registry: one line per builtin,
Word or Word arg, then root or pane for the ctl that takes it, so it is
always this build's own list.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/ninep/tree.zig b/src/ninep/tree.zig
index 13dfb0cf..53472a60 100644
--- a/src/ninep/tree.zig
+++ b/src/ninep/tree.zig
@@ -176,6 +176,7 @@ pub const TopFile = enum(u4) {
     new,
     focus,
     ctl,
+    commands,
 
     pub fn fileName(f: TopFile) []const u8 {
         return if (f == .root) "/" else @tagName(f);
@@ -185,7 +186,7 @@ pub const TopFile = enum(u4) {
         return switch (f) {
             .root, .pane => 0o755,
             .look, .exec, .log, .focus, .ctl => 0o666,
-            .README, .index, .status, .screen, .listeners, .new => 0o444,
+            .README, .index, .status, .screen, .listeners, .new, .commands => 0o444,
         };
     }
 
@@ -447,6 +448,7 @@ fn topSize(p: *Pardes, f: TopFile) u64 {
         .log => events.logLen(&p.fs.log),
         .listeners => screen.listenersLen(p),
         .ctl => ctl.rootLen(p),
+        .commands => ctl.commandsLen(),
         .focus => focus: {
             const pn = p.panes[p.active] orelse break :focus 0;
             var digits: [16]u8 = undefined;
@@ -525,7 +527,7 @@ fn readdir(p: *Pardes, req: Req, target: Target) Reply {
                 }
                 if (skip > 0) skip -= 1 else stageDirent(out, p.gpa, fs.os_root, true, "os");
                 // After the first ten, which older clients list by position.
-                inline for (.{ TopFile.focus, TopFile.ctl }) |t| {
+                inline for (.{ TopFile.focus, TopFile.ctl, TopFile.commands }) |t| {
                     if (skip > 0) skip -= 1 else stageDirent(out, p.gpa, @intFromEnum(t), t.dir(), t.fileName());
                 }
                 sources.stage(p, out, "", &skip);
@@ -719,6 +721,7 @@ fn read(p: *Pardes, req: Req, target: Target) Reply {
             .listeners => screen.readListeners(p, req),
             .focus => ctl.readFocus(p, req),
             .ctl => ctl.readRoot(p, req),
+            .commands => ctl.readCommands(p, req),
             // The serial the open handed this fid, so that two reads of one
             // fid answer the same pane: the read observes, the open acted.
             .new => serial: {