posix portability: linux syscalls -> libc (std.c) in one shared path. All raw std.os.linux.* call sites converted with the errno-convention flip (libc returns -1 + thread-local errno, not -errno): open/close/read/write/rename in tty.zig, gui.zig, look.zig; harness too (snapshot.zig: getcwd/mkdir/chdir/fork+waitpid/getdents64->opendir-readdir, e2e_harness.zig: clock_gettime/write/close), so the parity suite itself is POSIX-portable. Per-OS branches kept only where platforms genuinely diverge: shellCwd in look.zig (linux /proc/<pid>/cwd readlink; darwin libproc proc_pidinfo PROC_PIDVNODEPATHINFO with a hand-declared extern; other POSIX degrades to null), bash path (/usr/bin/bash on linux, /bin/bash elsewhere), TIOCSWINSZ constant (absent from std.c.T on darwin). forkpty/execv/chdir externs were already libc and are portable (fork-safety preserved: absolute-path execv, no malloc between fork and exec, initial spawns before worker threads). build.zig: forward target/optimize to the ghostty dep for native/cross (web keeps its no-target fetch), disable ghostty simd for darwin cross-builds (apple_sdk needs xcrun; scalar fallback = web config), link libutil on the BSDs. Pinned ghostty needs two one-line zig-0.16 darwin fixes, applied in the zig-pkg cache and documented in build.zig. Verified: aarch64-macos + x86_64-macos + x86_64-freebsd cross-compiles green; linux native tty + gui + web green; snapshot suite 18/18 with goldens untouched. Out of scope: gui-on-macos needs Metal shaders (SDL GPU rejects our SPIR-V there).

1 files changed, 29 insertions, 37 deletions

diff --git a/src/tty.zig b/src/tty.zig
index d9821343..9e2da26b 100644
--- a/src/tty.zig
+++ b/src/tty.zig
@@ -3,16 +3,24 @@
 //! them, resize them), and hands the core's Surface to vaxis cell-for-cell —
 //! the canonical interface rendered with no interpretation.
 const std = @import("std");
+const builtin = @import("builtin");
 const posix = std.posix;
-const linux = std.os.linux;
+const libc = std.c;
 const vaxis = @import("vaxis");
 const pardes = @import("pardes.zig");
+const look = @import("look.zig");
 
 extern "c" fn forkpty(amaster: *c_int, name: ?[*:0]u8, termp: ?*const anyopaque, winp: ?*const posix.winsize) c_int;
 extern "c" fn execv(path: [*:0]const u8, argv: [*:null]const ?[*:0]const u8) c_int;
 extern "c" fn chdir(path: [*:0]const u8) c_int;
 extern "c" fn _exit(status: c_int) noreturn;
 
+// absolute shell path per OS: execv must not search PATH (no allocation
+// between fork and exec)
+const bash_path: [*:0]const u8 = if (builtin.os.tag == .linux) "/usr/bin/bash" else "/bin/bash";
+// TIOCSWINSZ: absent from std.c.T on darwin — _IOW('t', 103, winsize)
+const TIOCSWINSZ: c_int = @bitCast(@as(u32, if (@hasDecl(posix.T, "IOCSWINSZ")) posix.T.IOCSWINSZ else 0x80087467));
+
 pub const Command = struct {
     pub var value: union(enum) {
         nop,
@@ -54,7 +62,7 @@ pub fn run(init: std.process.Init, opts: pardes.Options) !void {
     defer pardes.image.stop();
 
     const core = if (opts.load_path) |lp| blk: {
-        const bytes = try @import("look.zig").readFile(gpa, lp);
+        const bytes = try look.readFile(gpa, lp);
         defer gpa.free(bytes);
         break :blk try pardes.Pardes.initFromDump(gpa, opts, bytes);
     } else try pardes.Pardes.init(gpa, opts);
@@ -66,7 +74,7 @@ pub fn run(init: std.process.Init, opts: pardes.Options) !void {
     var kitty_handles: [pardes.MAX_PANES]?vaxis.Image = @splat(null);
     var ptys: [pardes.MAX_PANES]?Pty = @splat(null);
     defer for (&ptys) |*slot| if (slot.*) |*pt| {
-        _ = linux.close(pt.file.handle);
+        _ = libc.close(pt.file.handle);
         slot.* = null;
     };
 
@@ -104,7 +112,7 @@ pub fn run(init: std.process.Init, opts: pardes.Options) !void {
             },
             .pty_eof => |id| {
                 if (ptys[id]) |*pt| {
-                    _ = linux.close(pt.file.handle);
+                    _ = libc.close(pt.file.handle);
                     ptys[id] = null;
                 }
                 core.update(.{ .eof = .{ .pane = @intCast(id) } });
@@ -146,14 +154,10 @@ pub fn run(init: std.process.Init, opts: pardes.Options) !void {
         drainEffects(core, &ptys, io, gpa, &loop, &vx, &tty, true);
         if (core.quit) break;
 
-        // live cwd for tags/look: cheap /proc readlink per pane, per frame
+        // live cwd for tags/look: cheap per-pane lookup, per frame
         for (&ptys, 0..) |*slot, id| if (slot.*) |pt| {
             var lbuf: [1024]u8 = undefined;
-            var pbuf: [64]u8 = undefined;
-            const path = std.fmt.bufPrintSentinel(&pbuf, "/proc/{d}/cwd", .{pt.pid}, 0) catch continue;
-            const rc = linux.readlinkat(linux.AT.FDCWD, path, &lbuf, lbuf.len);
-            const n: isize = @bitCast(rc);
-            if (n > 0) core.setCwd(id, lbuf[0..@intCast(n)]);
+            if (look.shellCwd(pt.pid, &lbuf)) |cwd| core.setCwd(id, cwd);
         };
 
         // ---- render: surface -> vaxis, cell for cell ----
@@ -220,12 +224,7 @@ fn drainEffects(
             ptys[sp.pane] = .{ .file = child.file, .pid = child.pid, .reader = .{ .any_future = null, .result = {} } };
             // report the pane's starting directory back to the core (tags)
             var lbuf: [1024]u8 = undefined;
-            var pbuf: [64]u8 = undefined;
-            if (std.fmt.bufPrintSentinel(&pbuf, "/proc/{d}/cwd", .{child.pid}, 0) catch null) |path| {
-                const rc = linux.readlinkat(linux.AT.FDCWD, path, &lbuf, lbuf.len);
-                const n: isize = @bitCast(rc);
-                if (n > 0) core.setCwd(sp.pane, lbuf[0..@intCast(n)]);
-            }
+            if (look.shellCwd(child.pid, &lbuf)) |wd| core.setCwd(sp.pane, wd);
             if (threads_ok) {
                 if (ptys[sp.pane]) |*pt| {
                     pt.reader = io.concurrent(readPty, .{ io, gpa, pt.file, @as(usize, sp.pane), loop }) catch pt.reader;
@@ -238,7 +237,7 @@ fn drainEffects(
         .resize_pty => |rs| {
             if (ptys[rs.pane]) |pt| {
                 const ws: posix.winsize = .{ .row = rs.rows, .col = rs.cols, .xpixel = 0, .ypixel = 0 };
-                _ = posix.system.ioctl(pt.file.handle, posix.T.IOCSWINSZ, @intFromPtr(&ws));
+                _ = posix.system.ioctl(pt.file.handle, TIOCSWINSZ, @intFromPtr(&ws));
             }
         },
         .open_link => {}, // tty: no link handling (look opens panes instead)
@@ -249,21 +248,17 @@ fn drainEffects(
             if (f.path.len >= pathbuf.len) continue;
             @memcpy(pathbuf[0..f.path.len], f.path);
             pathbuf[f.path.len] = 0;
-            const rc = linux.open(pathbuf[0..f.path.len :0], .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, 0o644);
-            const sfd: isize = @bitCast(rc);
-            if (sfd < 0) continue;
-            const fd: c_int = @intCast(sfd);
+            const fd = libc.open(pathbuf[0..f.path.len :0], .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644));
+            if (fd < 0) continue;
             writeFd(fd, f.content);
-            _ = linux.close(fd);
+            _ = libc.close(fd);
         },
         .write_dump => {
             const out = core.dump_out orelse continue;
-            const rc = linux.open(pardes.dump.default_path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, 0o644);
-            const sfd: isize = @bitCast(rc);
-            if (sfd < 0) continue;
-            const fd: c_int = @intCast(sfd);
+            const fd = libc.open(pardes.dump.default_path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644));
+            if (fd < 0) continue;
             writeFd(fd, out);
-            _ = linux.close(fd);
+            _ = libc.close(fd);
         },
         .set_clipboard => {
             // mirror the core's yank register out via OSC 52
@@ -280,8 +275,8 @@ fn forkShell(cwd: ?[*:0]const u8, rows: u16, cols: u16) struct { file: std.Io.Fi
     const pid = forkpty(&master, null, null, &ws);
     if (pid == 0) {
         if (cwd) |c| _ = chdir(c);
-        const argv: [4:null]?[*:0]const u8 = .{ "/usr/bin/bash", "--rcfile", "/tmp/pardes-osc133.bash", null };
-        _ = execv("/usr/bin/bash", &argv);
+        const argv: [4:null]?[*:0]const u8 = .{ bash_path, "--rcfile", "/tmp/pardes-osc133.bash", null };
+        _ = execv(bash_path, &argv);
         _exit(127);
     }
     return .{ .file = .{ .handle = master, .flags = .{ .nonblocking = false } }, .pid = pid };
@@ -364,21 +359,18 @@ fn vaxisColor(c: pardes.Color) vaxis.Color {
 }
 
 fn writeFile(data: []const u8) void {
-    const rc = linux.open("/tmp/pardes-osc133.bash", .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, 0o644);
-    const sfd: isize = @bitCast(rc);
-    if (sfd < 0) return;
-    const fd: c_int = @intCast(sfd);
-    defer _ = linux.close(fd);
+    const fd = libc.open("/tmp/pardes-osc133.bash", .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644));
+    if (fd < 0) return;
+    defer _ = libc.close(fd);
     writeFd(fd, data);
 }
 
 fn writeFd(fd: c_int, data: []const u8) void {
     var off: usize = 0;
     while (off < data.len) {
-        const rc = linux.write(fd, data[off..].ptr, data.len - off);
-        const n: isize = @bitCast(rc);
+        const n = libc.write(fd, data[off..].ptr, data.len - off);
         if (n < 0) {
-            if (n == -@as(isize, @intFromEnum(linux.E.INTR))) continue;
+            if (libc.errno(n) == .INTR) continue;
             return;
         }
         off += @intCast(n);