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Merged
sylvestre merged 2 commits into from
Oct 12, 2026
+88 −10
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uutests: open simulated terminals close-on-exec #15217

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95217b2
uutests: open simulated terminals close-on-exec
abendrothj Oct 10, 2026
823ef1b
tests: more: kill more at the end of each pty test
abendrothj Oct 11, 2026
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17 changes: 17 additions & 0 deletions tests/by-util/test_env.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1885,6 +1885,23 @@ fn test_simulation_of_terminal_pty_pipes_into_data_and_sends_eot_automatically()
std::assert_eq!(String::from_utf8_lossy(out.stderr()), "");
}

#[cfg(target_os = "linux")]
#[test]
fn test_simulation_of_terminal_not_inherited_by_other_commands() {
let scene = TestScenario::new("util");

@sylvestre sylvestre Oct 10, 2026

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sleep 1 would be enough, no?

@abendrothj abendrothj Oct 11, 2026

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Done.


let mut cmd = scene.ccmd("env");
cmd.args(&["sleep", "1"]);
cmd.terminal_simulation(true);
let mut child = cmd.run_no_wait();
scene
.ccmd("env")
.args(&["ls", "-l", "/proc/self/fd/"])
.succeeds()
.stdout_does_not_contain("/dev/ptmx");
child.kill();
}

#[test]
#[cfg(not(windows))]
fn test_emoji_env_vars() {
Expand Down
7 changes: 4 additions & 3 deletions tests/by-util/test_more.rs
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Expand Up @@ -47,6 +47,9 @@ fn run_more_with_pty(
fn quit_more(controller: &mut File, mut child: uutests::util::UChild) {
controller.write_all(b"q").unwrap();
child.delay(50);
// Not all options quit on `q` here, and a `more` left behind spins once
// its terminal hangs up.
child.kill();
}

#[cfg(unix)]
Expand Down Expand Up @@ -110,9 +113,7 @@ fn test_alive(args: &[&str]) {

assert!(child.is_alive(), "Command should still be alive");

// cleanup
controller.write_all(b"q").unwrap();
child.delay(50);
quit_more(&mut controller, child);
}

#[test]
Expand Down
2 changes: 1 addition & 1 deletion tests/uutests/Cargo.toml
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Expand Up @@ -37,7 +37,7 @@ uucore = { workspace = true, features = [

[target.'cfg(unix)'.dependencies]
nix = { workspace = true, features = ["fs", "term"] }
rustix = { workspace = true, features = ["process"] }
rustix = { workspace = true, features = ["process", "pty", "termios"] }

[target.'cfg(any(target_os = "freebsd", target_os = "hurd", target_os = "linux", target_os = "android", target_os = "netbsd"))'.dependencies]
xattr = { workspace = true }
Expand Down
72 changes: 66 additions & 6 deletions tests/uutests/src/lib/util.rs
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Expand Up @@ -3,7 +3,7 @@
// For the full copyright and license information, please view the LICENSE
// file that was distributed with this source code.

//spell-checker:ignore (linux) rlimit prlimit coreutil ggroups uchild uncaptured scmd SHLVL canonicalized openpty
//spell-checker:ignore (linux) rlimit prlimit coreutil ggroups uchild uncaptured scmd SHLVL canonicalized openpty openpt grantpt unlockpt ptsname tcsetwinsize CLOEXEC RDWR SETFD
//spell-checker:ignore (linux) winsize xpixel ypixel setrlimit Fsize SIGBUS SIGSEGV SIGXFSZ EFBIG sigbus tmpfs mksocket
//spell-checker:ignore (ToDO) ttyname

Expand Down Expand Up @@ -2038,7 +2038,11 @@ impl UCommand {
let OpenptyResult {
slave: pi_slave,
master: pi_master,
} = nix::pty::openpty(&terminal_size, None).unwrap();
} = open_pty(Some(&terminal_size));
// Read the echo, as a terminal would. This also keeps the PTY
// open until the child closes it, so closing stdin doesn't hang it up.
let mut echo = File::from(pi_master.try_clone().unwrap());
thread::spawn(move || io::copy(&mut echo, &mut io::sink()));
stdin_pty = Some(File::from(pi_master));
command.stdin(pi_slave);
}
Expand All @@ -2047,7 +2051,7 @@ impl UCommand {
let OpenptyResult {
slave: po_slave,
master: po_master,
} = nix::pty::openpty(&terminal_size, None).unwrap();
} = open_pty(Some(&terminal_size));
captured_stdout = Self::spawn_reader_thread(
captured_stdout,
po_master,
Expand All @@ -2060,7 +2064,7 @@ impl UCommand {
let OpenptyResult {
slave: pe_slave,
master: pe_master,
} = nix::pty::openpty(&terminal_size, None).unwrap();
} = open_pty(Some(&terminal_size));
captured_stderr = Self::spawn_reader_thread(
captured_stderr,
pe_master,
Expand Down Expand Up @@ -3038,6 +3042,63 @@ pub fn whoami() -> String {
})
}

/// Open a PTY whose two ends are close-on-exec, so that commands started by
/// other tests in the meantime don't inherit them.
#[cfg(all(unix, not(target_os = "redox")))]
fn open_pty(size: Option<&libc::winsize>) -> OpenptyResult {

@xtqqczze xtqqczze Oct 13, 2026

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This fails to compile on NetBSD targets:

$ RUSTC_BOOTSTRAP=1 cargo clippy -q -Zbuild-std -p uutests --target i686-unknown-netbsd
error[E0432]: unresolved import `rustix::pty::ptsname`
    --> tests/uutests/src/lib/util.rs:3057:57
     |
3057 |         use rustix::pty::{OpenptFlags, grantpt, openpt, ptsname, unlockpt};
     |                                                         ^^^^^^^ no `ptsname` in `pty`
     |
note: found an item that was configured out
    --> ~/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rustix-1.1.5/src/pty.rs:135:8
     |
 124 |       any(
     |  ________-
 125 | |         apple,
 126 | |         linux_like,
 127 | |         target_os = "freebsd",
 128 | |         target_os = "fuchsia",
 129 | |         target_os = "illumos"
 130 | |     )
     | |_____- the item is gated here
...
 135 |   pub fn ptsname<Fd: AsFd, B: Into<Vec<u8>>>(fd: Fd, reuse: B) -> io::Result<CString> {
     |          ^^^^^^^

For more information about this error, try `rustc --explain E0432`.

@xtqqczze xtqqczze Oct 13, 2026

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Will address in #14252

@abendrothj abendrothj Oct 14, 2026

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Thanks, I missed that rustix has no ptsname on NetBSD.

#[cfg(any(
target_os = "linux",
target_os = "android",
target_os = "freebsd",
target_os = "netbsd"
))]
{
use rustix::fs::{Mode, OFlags, open};
use rustix::pty::{OpenptFlags, grantpt, openpt, ptsname, unlockpt};
use rustix::termios::{Winsize, tcsetwinsize};

let master =
openpt(OpenptFlags::RDWR | OpenptFlags::NOCTTY | OpenptFlags::CLOEXEC).unwrap();
grantpt(&master).unwrap();
unlockpt(&master).unwrap();
let name = ptsname(&master, Vec::new()).unwrap();
let slave = open(
name,
OFlags::RDWR | OFlags::NOCTTY | OFlags::CLOEXEC,
Mode::empty(),
)
.unwrap();
if let Some(size) = size {
let size = Winsize {
ws_row: size.ws_row,
ws_col: size.ws_col,
ws_xpixel: size.ws_xpixel,
ws_ypixel: size.ws_ypixel,
};
tcsetwinsize(&slave, size).unwrap();
}
OpenptyResult { master, slave }
}

// Elsewhere a PTY can't be opened close-on-exec, so a command started
// between openpty and fcntl can still inherit it.
#[cfg(not(any(
target_os = "linux",
target_os = "android",
target_os = "freebsd",

@sylvestre sylvestre Oct 10, 2026

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same cfg list twice, could it be a single cfg_if! or an else branch?

@abendrothj abendrothj Oct 11, 2026

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There's no cfg_if in the tree, and cfg_select! isn't available at our 1.88 MSRV. A cfg!() if/else would need both branches to compile everywhere, but OpenptFlags::CLOEXEC only exists on Linux, Android, FreeBSD and NetBSD. I can name the list once with a cfg_aliases build.rs in uutests, if you prefer.

target_os = "netbsd"
)))]
{
use nix::fcntl::{FcntlArg, FdFlag, fcntl};

let pty = nix::pty::openpty(size, None).unwrap();
for fd in [&pty.master, &pty.slave] {
fcntl(fd, FcntlArg::F_SETFD(FdFlag::FD_CLOEXEC)).unwrap();
}
pty
}
}

/// Create a PTY (pseudo-terminal) for testing utilities that require a TTY.
///
/// Returns a tuple of (path, controller, replica) where:
Expand All @@ -3046,9 +3107,8 @@ pub fn whoami() -> String {
/// - replica: The replica file
#[cfg(all(unix, not(target_os = "redox")))]
pub fn pty_path() -> (String, File, File) {
use nix::pty::openpty;
use nix::unistd::ttyname;
let pty = openpty(None, None).expect("Failed to create PTY");
let pty = open_pty(None);
let path = ttyname(&pty.slave)
.expect("Failed to get PTY path")
.to_string_lossy()
Expand Down
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