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).

3 files changed, 117 insertions, 102 deletions

diff --git a/src/gui.zig b/src/gui.zig
index 516a6b79..c1881c7c 100644
--- a/src/gui.zig
+++ b/src/gui.zig
@@ -1,6 +1,6 @@
 //! The SDL3 GPU shell: owns an SDL window + event loop, translates SDL input
 //! into core events, performs the core's effects (fork ptys, write them,
-//! resize them — same duties as tty.zig, this is also native linux), and
+//! resize them — same duties as tty.zig, this is also native), and
 //! rasterizes the core's Surface: one instanced quad per cell, glyphs from an
 //! stb_truetype R8 atlas. Test modes: PARDES_TEST_GRID=1 is headless (no SDL,
 //! stdin escape sequences in, text grid frames out); PARDES_TEST=1 keeps the
@@ -13,10 +13,11 @@
 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"); // test modes only: the stdin escape-seq parser
 const ghostty_vt = @import("ghostty-vt"); // 256-color palette for .index cells
 const pardes = @import("pardes.zig");
+const look = @import("look.zig");
 
 const is_emscripten = builtin.os.tag == .emscripten;
 
@@ -34,6 +35,12 @@ extern "c" fn _exit(status: c_int) noreturn;
 extern "c" fn emscripten_get_element_css_size(target: [*:0]const u8, width: *f64, height: *f64) c_int;
 const EMSCRIPTEN_RESULT_SUCCESS: c_int = 0;
 
+// 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));
+
 const log = std.log.scoped(.gui);
 
 const font_ttf = @embedFile("AdwaitaMono-Regular.ttf");
@@ -271,7 +278,7 @@ fn normCell(norm: f32, win: f32, cell: f32) u16 {
 
 // ---- pty plumbing: reader threads feed a mutex-protected queue ----
 
-const Pty = struct { fd: c_int, pid: linux.pid_t };
+const Pty = struct { fd: c_int, pid: libc.pid_t };
 
 const Msg = union(enum) { output: struct { pane: u8, bytes: []u8 }, eof: u8 };
 
@@ -338,10 +345,9 @@ const Queue = struct {
 fn readPtyThread(gpa: std.mem.Allocator, fd: c_int, pane: u8, q: *Queue) void {
     var buf: [0x10000]u8 = undefined;
     while (true) {
-        const rc = linux.read(fd, &buf, buf.len);
-        const n: isize = @bitCast(rc);
+        const n = libc.read(fd, &buf, buf.len);
         if (n < 0) {
-            if (n == -@as(isize, @intFromEnum(linux.E.INTR))) continue;
+            if (libc.errno(n) == .INTR) continue;
             break; // EIO when the child exits: treat as EOF
         }
         if (n == 0) break;
@@ -622,7 +628,7 @@ fn runNative(init: std.process.Init, opts_in: pardes.Options) !void {
 
     var ptys: [pardes.MAX_PANES]?Pty = @splat(null);
     defer for (&ptys) |*slot| if (slot.*) |pt| {
-        _ = linux.close(pt.fd);
+        _ = libc.close(pt.fd);
         slot.* = null;
     };
     var queue: Queue = .{ .gpa = gpa, .sdl_wake = true };
@@ -662,7 +668,7 @@ fn runNative(init: std.process.Init, opts_in: pardes.Options) !void {
             },
             .eof => |id| {
                 if (ptys[id]) |pt| {
-                    _ = linux.close(pt.fd);
+                    _ = libc.close(pt.fd);
                     ptys[id] = null;
                 }
                 core.update(.{ .eof = .{ .pane = id } });
@@ -895,7 +901,7 @@ fn runGrid(init: std.process.Init, opts_in: pardes.Options) !void {
 
     var ptys: [pardes.MAX_PANES]?Pty = @splat(null);
     defer for (&ptys) |*slot| if (slot.*) |pt| {
-        _ = linux.close(pt.fd);
+        _ = libc.close(pt.fd);
         slot.* = null;
     };
     var queue: Queue = .{ .gpa = gpa, .sdl_wake = false };
@@ -927,7 +933,7 @@ fn runGrid(init: std.process.Init, opts_in: pardes.Options) !void {
             },
             .eof => |id| {
                 if (ptys[id]) |pt| {
-                    _ = linux.close(pt.fd);
+                    _ = libc.close(pt.fd);
                     ptys[id] = null;
                 }
                 core.update(.{ .eof = .{ .pane = id } });
@@ -981,8 +987,7 @@ const StdinFeed = struct {
             if ((fds[0].revents & (posix.POLL.HUP | posix.POLL.ERR)) != 0) out.eof = true;
             return out;
         }
-        const rc = linux.read(0, f.buf[f.fill..].ptr, f.buf.len - f.fill);
-        const rn: isize = @bitCast(rc);
+        const rn = libc.read(0, f.buf[f.fill..].ptr, f.buf.len - f.fill);
         if (rn < 0) return out;
         if (rn == 0) {
             out.eof = true;
@@ -1433,12 +1438,7 @@ fn drainEffects(
             ptys[sp.pane] = pt;
             // 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", .{pt.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(pt.pid, &lbuf)) |wd| core.setCwd(sp.pane, wd);
             if (threads_ok) spawnReader(gpa, pt, sp.pane, queue);
         },
         .write => |w| {
@@ -1447,7 +1447,7 @@ 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.fd, posix.T.IOCSWINSZ, @intFromPtr(&ws));
+                _ = posix.system.ioctl(pt.fd, TIOCSWINSZ, @intFromPtr(&ws));
             }
         },
         .open_link => {}, // native: look opens panes instead; nothing to launch
@@ -1458,21 +1458,17 @@ 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 => {
             if (g == null) continue;
@@ -1500,8 +1496,8 @@ fn forkShell(cwd: ?[*:0]const u8, rows: u16, cols: u16) Pty {
     const pid = forkpty(&master, null, null, &ws);
     if (pid == 0) {
         if (cwd) |cd| _ = chdir(cd);
-        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 .{ .fd = master, .pid = pid };
@@ -1510,11 +1506,7 @@ fn forkShell(cwd: ?[*:0]const u8, rows: u16, cols: u16) Pty {
 fn pollCwds(core: *pardes.Pardes, ptys: *[pardes.MAX_PANES]?Pty) void {
     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);
     };
 }
 
@@ -2073,11 +2065,9 @@ fn writeCapturePpm(g: *Gui, gpa: std.mem.Allocator, pixels: []const u8, width: u
     const tmp_path = std.fmt.bufPrintSentinel(&tmp_buf, "{s}/latest.ppm.tmp", .{g.capture_dir}, 0) catch return error.CapturePathTooLong;
     const final_path = std.fmt.bufPrintSentinel(&final_buf, "{s}/latest.ppm", .{g.capture_dir}, 0) catch return error.CapturePathTooLong;
 
-    const orc = linux.open(tmp_path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, 0o644);
-    const sfd: isize = @bitCast(orc);
-    if (sfd < 0) return error.CaptureWriteFailed;
-    const fd: c_int = @intCast(sfd);
-    defer _ = linux.close(fd);
+    const fd = libc.open(tmp_path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644));
+    if (fd < 0) return error.CaptureWriteFailed;
+    defer _ = libc.close(fd);
 
     var header: [64]u8 = undefined;
     const hdr = std.fmt.bufPrint(&header, "P6\n{d} {d}\n255\n", .{ width, height }) catch return error.CaptureWriteFailed;
@@ -2096,9 +2086,7 @@ fn writeCapturePpm(g: *Gui, gpa: std.mem.Allocator, pixels: []const u8, width: u
         }
         writeFd(fd, row_rgb);
     }
-    const rrc = linux.rename(tmp_path, final_path);
-    const rs: isize = @bitCast(rrc);
-    if (rs < 0) return error.CaptureWriteFailed;
+    if (libc.rename(tmp_path, final_path) != 0) return error.CaptureWriteFailed;
 }
 
 // =====================================================================
@@ -2377,21 +2365,18 @@ fn envU16(env: *std.process.Environ.Map, name: []const u8) ?u16 {
 }
 
 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);
diff --git a/src/look.zig b/src/look.zig
index 67fbf8c5..8744da24 100644
--- a/src/look.zig
+++ b/src/look.zig
@@ -8,7 +8,8 @@
 //!   web      — there is no filesystem; only URLs mean anything, and a URL
 //!              opens in a new tab (the open_link effect).
 const std = @import("std");
-const linux = std.os.linux;
+const builtin = @import("builtin");
+const libc = std.c;
 const pardes = @import("pardes.zig");
 
 extern "c" fn realpath(path: [*:0]const u8, resolved: [*]u8) ?[*:0]u8;
@@ -88,10 +89,9 @@ const platform_has_fs = switch (pardes.platform) {
 
 /// true if `path` exists and is a directory (open(O_DIRECTORY), no stat needed)
 fn isDir(path: [*:0]const u8) bool {
-    const rc = linux.open(path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true, .CLOEXEC = true }, 0);
-    const sfd: isize = @bitCast(rc);
-    if (sfd < 0) return false;
-    _ = linux.close(@intCast(sfd));
+    const fd = libc.open(path, .{ .ACCMODE = .RDONLY, .DIRECTORY = true, .CLOEXEC = true });
+    if (fd < 0) return false;
+    _ = libc.close(fd);
     return true;
 }
 
@@ -101,19 +101,16 @@ pub fn readFile(gpa: std.mem.Allocator, path: []const u8) ![]u8 {
     if (!platform_has_fs) return error.NoFilesystem;
     var pathbuf: [4096]u8 = undefined;
     const path_z = std.fmt.bufPrintSentinel(&pathbuf, "{s}", .{path}, 0) catch return error.PathTooLong;
-    const rc = linux.open(path_z, .{ .ACCMODE = .RDONLY }, 0);
-    const sfd: isize = @bitCast(rc);
-    if (sfd < 0) return error.OpenFailed;
-    const fd: i32 = @intCast(sfd);
-    defer _ = linux.close(fd);
+    const fd = libc.open(path_z, .{ .ACCMODE = .RDONLY });
+    if (fd < 0) return error.OpenFailed;
+    defer _ = libc.close(fd);
     var buf: std.ArrayList(u8) = .empty;
     errdefer buf.deinit(gpa);
     var chunk: [16384]u8 = undefined;
     while (true) {
-        const r = linux.read(fd, &chunk, chunk.len);
-        const n: isize = @bitCast(r);
+        const n = libc.read(fd, &chunk, chunk.len);
         if (n < 0) {
-            if (n == -@as(isize, @intFromEnum(linux.E.INTR))) continue;
+            if (libc.errno(n) == .INTR) continue;
             return error.ReadFailed;
         }
         if (n == 0) break;
@@ -121,3 +118,44 @@ pub fn readFile(gpa: std.mem.Allocator, path: []const u8) ![]u8 {
     }
     return buf.toOwnedSlice(gpa);
 }
+
+// ---- shell cwd: what directory a pane's looks resolve against ----
+
+// macOS has no /proc; libproc's proc_pidinfo(PROC_PIDVNODEPATHINFO) yields the
+// cwd vnode path. Not in std.c — layout from xnu's sys/proc_info.h.
+const vnode_info_path = extern struct {
+    vi: [152]u8 align(8), // struct vnode_info: vinfo_stat + type + pad + fsid
+    path: [1024]u8, // MAXPATHLEN
+};
+const proc_vnodepathinfo = extern struct {
+    cdir: vnode_info_path,
+    rdir: vnode_info_path,
+};
+const PROC_PIDVNODEPATHINFO: c_int = 9;
+extern "c" fn proc_pidinfo(pid: c_int, flavor: c_int, arg: u64, buffer: *anyopaque, buffersize: c_int) c_int;
+
+/// Live cwd of a shell process (pane tags, look resolution). linux reads
+/// /proc/<pid>/cwd, darwin asks libproc; other POSIX systems have no cheap
+/// answer — return null and panes keep their spawn-time cwd (callers already
+/// tolerate failure: dead shells have no cwd either).
+pub fn shellCwd(pid: libc.pid_t, buf: *[1024]u8) ?[]const u8 {
+    switch (builtin.os.tag) {
+        .linux => {
+            var pbuf: [64]u8 = undefined;
+            const path = std.fmt.bufPrintSentinel(&pbuf, "/proc/{d}/cwd", .{pid}, 0) catch return null;
+            const n = libc.readlink(path, buf, buf.len);
+            if (n <= 0) return null;
+            return buf[0..@intCast(n)];
+        },
+        .macos, .ios, .tvos, .watchos, .visionos => {
+            var info: proc_vnodepathinfo = undefined;
+            const n = proc_pidinfo(pid, PROC_PIDVNODEPATHINFO, 0, &info, @sizeOf(proc_vnodepathinfo));
+            if (n < @as(c_int, @sizeOf(proc_vnodepathinfo))) return null;
+            const path = std.mem.sliceTo(&info.cdir.path, 0);
+            if (path.len == 0) return null;
+            @memcpy(buf[0..path.len], path);
+            return buf[0..path.len];
+        },
+        else => return null,
+    }
+}
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);