From 8aafc3fa24c7475a07259eb06cd5d217f510df98 Mon Sep 17 00:00:00 2001
From: Gabriel Schneider <gbrls@0x4200.cafe>
Date: Wed, 5 Aug 2026 19:32:30 -0300
Subject: add a Shell builtin, default fish, with per-family prompt integration

---
 src/gui/gui.zig | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

(limited to 'src/gui/gui.zig')

diff --git a/src/gui/gui.zig b/src/gui/gui.zig
index a4883fa6..e1d5c86d 100644
--- a/src/gui/gui.zig
+++ b/src/gui/gui.zig
@@ -28,6 +28,7 @@ const selection_pipe = @import("../selection_pipe.zig");
 
 const is_emscripten = builtin.os.tag == .emscripten;
 const temp_file = if (is_emscripten) struct {} else @import("../temp_file.zig");
+const shell_bin = if (is_emscripten) struct {} else @import("../shell_bin.zig");
 
 pub const c = @cImport({
     @cDefine("SDL_DISABLE_OLD_NAMES", "1");
@@ -44,9 +45,6 @@ extern "c" fn setenv(name: [*:0]const u8, value: [*:0]const u8, overwrite: c_int
 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));
 
@@ -1272,7 +1270,8 @@ fn runNative(init: std.process.Init, opts_in: pardes.Options) !void {
     core.native_images = true;
 
     // shells emit OSC 133 prompt marks via this rc (prompt hiding, click-move)
-    writeFile(pardes.bash_rc);
+    writeFile(shell_bin.bash_rc_path, shell_bin.bash_rc);
+    writeFile(shell_bin.fish_rc_path, shell_bin.fish_rc);
     // macos: apple's bash 3.2 prints the zsh-deprecation banner into every
     // pane unless this is in the env BEFORE bash starts (the rc is too late)
     if (comptime builtin.os.tag.isDarwin()) _ = setenv("BASH_SILENCE_DEPRECATION_WARNING", "1", 1);
@@ -1775,7 +1774,8 @@ fn runGrid(init: std.process.Init, opts_in: pardes.Options) !void {
     if (opts.load_path == null)
         core.update(.{ .resize = .{ .cols = grid_cols, .rows = grid_rows } });
 
-    writeFile(pardes.bash_rc);
+    writeFile(shell_bin.bash_rc_path, shell_bin.bash_rc);
+    writeFile(shell_bin.fish_rc_path, shell_bin.fish_rc);
     // macos: apple's bash 3.2 prints the zsh-deprecation banner into every
     // pane unless this is in the env BEFORE bash starts (the rc is too late)
     if (comptime builtin.os.tag.isDarwin()) _ = setenv("BASH_SILENCE_DEPRECATION_WARNING", "1", 1);
@@ -2599,7 +2599,7 @@ fn drainEffects(
                 cwd_buf[cwd.len] = 0;
                 cwd_z = @ptrCast(&cwd_buf);
             }
-            const pt = forkShell(cwd_z, core.screen_h, core.screen_w);
+            const pt = forkShell(core.shellBin(), cwd_z, core.screen_h, core.screen_w);
             ptys[sp.pane] = pt;
             // report the pane's starting directory back to the core (tags)
             var lbuf: [1024]u8 = undefined;
@@ -2678,14 +2678,17 @@ fn drainEffects(
     };
 }
 
-fn forkShell(cwd: ?[*:0]const u8, rows: u16, cols: u16) Pty {
+fn forkShell(bin: []const u8, cwd: ?[*:0]const u8, rows: u16, cols: u16) Pty {
     var master: c_int = undefined;
+    // resolved BEFORE the fork, into this frame, which the child inherits:
+    // nothing between fork and exec may allocate, and a PATH search would
+    var path_buf: [std.fs.max_path_bytes]u8 = undefined;
+    const spawn = shell_bin.resolve(bin, &path_buf);
     const ws = posix.winsize{ .row = rows, .col = cols, .xpixel = 0, .ypixel = 0 };
     const pid = forkpty(&master, null, null, &ws);
     if (pid == 0) {
         if (cwd) |cd| _ = chdir(cd);
-        const argv: [4:null]?[*:0]const u8 = .{ bash_path, "--rcfile", "/tmp/pardes-osc133.bash", null };
-        _ = execv(bash_path, &argv);
+        _ = execv(spawn.path, &spawn.argv);
         _exit(127);
     }
     return .{ .fd = master, .pid = pid };
@@ -4281,8 +4284,8 @@ fn envU16(env: *std.process.Environ.Map, name: []const u8) ?u16 {
     return std.fmt.parseInt(u16, raw, 10) catch null;
 }
 
-fn writeFile(data: []const u8) void {
-    const fd = libc.open("/tmp/pardes-osc133.bash", .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644));
+fn writeFile(path: [*:0]const u8, data: []const u8) void {
+    const fd = libc.open(path, .{ .ACCMODE = .WRONLY, .CREAT = true, .TRUNC = true }, @as(libc.mode_t, 0o644));
     if (fd < 0) return;
     defer _ = libc.close(fd);
     writeFd(fd, data);
-- 
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