From 5ee1e87a917bdca38351feeca88999cd67440994 Mon Sep 17 00:00:00 2001 From: Gabriel Schneider Date: Mon, 28 Sep 2026 22:01:41 -0300 Subject: A command pane's background job outlives its command A dogfood agent's background jobs died when the command that started them finished, even under nohup. The command's shell leads its terminal's session, and on its exit the kernel hangs up the terminal's foreground group, which with job control off is the shell's and every job's. The line now runs with job control on (bash, sh, dash, zsh, ksh -m; fish status job-control full), so a job has a group of its own and lives on, printing below exit N, and survives the pane closing. While a job holds the pty the pane is not reused, so the directory's next command gets a second pane (cmdexit's golden, re-recorded by name). Co-Authored-By: Claude Opus 5.5 --- src/host_io.zig | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/host_io.zig b/src/host_io.zig index 25bd61e1..53e1628d 100644 --- a/src/host_io.zig +++ b/src/host_io.zig @@ -792,7 +792,7 @@ pub const Shell = struct { pub const Spawn = struct { path: [*:0]const u8, - argv: [4:null]?[*:0]const u8, + argv: [6:null]?[*:0]const u8, }; // Resolve in the parent. The path buffer and prompt files must survive through exec. @@ -803,7 +803,24 @@ pub const Shell = struct { .fish => if (prompt_rcs.fishCommand()) |command| .{ "-C", command.ptr } else .{ null, null }, .none => .{ null, null }, }; - return .{ .path = path, .argv = .{ path, marks[0], marks[1], null } }; + return .{ .path = path, .argv = .{ path, marks[0], marks[1], null, null, null } }; + } + + /// A command pane's shell runs its one line with job control on, so a + /// job the line puts in the background has a process group of its own. + /// The shell leads the terminal's session, and when it exits the kernel + /// hangs up the terminal's foreground group: with job control off that + /// is the shell's own, the job's too, and the job died with the command + /// (nohup'd or not; only setsid got out, and not always in time). A + /// shell pardes does not know runs the line as it is. + pub fn commandArgv(path: [*:0]const u8, line: [*:0]const u8) [6:null]?[*:0]const u8 { + const bin = std.mem.span(path); + const base = if (std.mem.lastIndexOfScalar(u8, bin, '/')) |s| bin[s + 1 ..] else bin; + const posix_shells = [_][]const u8{ "bash", "sh", "dash", "zsh", "ksh", "mksh", "yash" }; + for (posix_shells) |name| if (std.mem.eql(u8, base, name)) + return .{ path, "-m", "-c", line, null, null }; + if (family(bin) == .fish) return .{ path, "-C", "status job-control full", "-c", line, null }; + return .{ path, "-c", line, null, null, null }; } /// A shell by its path or its name in the usual directories, or null. @@ -840,6 +857,20 @@ pub const Shell = struct { return @ptrCast(buf); } + test "a command pane's line runs with job control on in the shells that have it" { + const want = struct { + fn check(path: [*:0]const u8, words: []const []const u8) !void { + const argv = commandArgv(path, "sleep 9 &"); + for (words, 0..) |w, i| try std.testing.expectEqualStrings(w, std.mem.span(argv[i].?)); + try std.testing.expect(argv[words.len] == null); + } + }; + try want.check("/usr/bin/bash", &.{ "/usr/bin/bash", "-m", "-c", "sleep 9 &" }); + try want.check("/bin/sh", &.{ "/bin/sh", "-m", "-c", "sleep 9 &" }); + try want.check("/usr/bin/fish", &.{ "/usr/bin/fish", "-C", "status job-control full", "-c", "sleep 9 &" }); + try want.check("/usr/bin/nu", &.{ "/usr/bin/nu", "-c", "sleep 9 &" }); + } + test "a path is taken at its word, a name is looked up, and both pick their own marks" { if (builtin.os.tag == .windows) return; var buf: [std.fs.max_path_bytes]u8 = undefined; @@ -1070,7 +1101,7 @@ pub fn forkShell( if (line.len > exec_command_max or std.mem.indexOfScalar(u8, line, 0) != null) return error.InvalidCommand; @memcpy(command_buf[0..line.len], line); command_buf[line.len] = 0; - spawn.argv = .{ spawn.path, "-c", command_buf[0..line.len :0].ptr, null }; + spawn.argv = Shell.commandArgv(spawn.path, command_buf[0..line.len :0].ptr); } var helper_buf: [4096]u8 = undefined; const mounted = one_line == null and if (core) |c| if (c.panes[pane]) |pn| pn.v9fs_on_spawn else false else false; -- cgit v1.3