1//! A module for working with processes.
2//!
3//! This module is mostly concerned with spawning and interacting with child
4//! processes, but it also provides [`abort`] and [`exit`] for terminating the
5//! current process.
6//!
7//! # Spawning a process
8//!
9//! The [`Command`] struct is used to configure and spawn processes:
10//!
11//! ```no_run
12//! use std::process::Command;
13//!
14//! let output = Command::new("echo")
15//! .arg("Hello world")
16//! .output()
17//! .expect("Failed to execute command");
18//!
19//! assert_eq!(b"Hello world\n", output.stdout.as_slice());
20//! ```
21//!
22//! Several methods on [`Command`], such as [`spawn`] or [`output`], can be used
23//! to spawn a process. In particular, [`output`] spawns the child process and
24//! waits until the process terminates, while [`spawn`] will return a [`Child`]
25//! that represents the spawned child process.
26//!
27//! # Handling I/O
28//!
29//! The [`stdout`], [`stdin`], and [`stderr`] of a child process can be
30//! configured by passing an [`Stdio`] to the corresponding method on
31//! [`Command`]. Once spawned, they can be accessed from the [`Child`]. For
32//! example, piping output from one command into another command can be done
33//! like so:
34//!
35//! ```no_run
36//! use std::process::{Command, Stdio};
37//!
38//! // stdout must be configured with `Stdio::piped` in order to use
39//! // `echo_child.stdout`
40//! let echo_child = Command::new("echo")
41//! .arg("Oh no, a tpyo!")
42//! .stdout(Stdio::piped())
43//! .spawn()
44//! .expect("Failed to start echo process");
45//!
46//! // Note that `echo_child` is moved here, but we won't be needing
47//! // `echo_child` anymore
48//! let echo_out = echo_child.stdout.expect("Failed to open echo stdout");
49//!
50//! let mut sed_child = Command::new("sed")
51//! .arg("s/tpyo/typo/")
52//! .stdin(Stdio::from(echo_out))
53//! .stdout(Stdio::piped())
54//! .spawn()
55//! .expect("Failed to start sed process");
56//!
57//! let output = sed_child.wait_with_output().expect("Failed to wait on sed");
58//! assert_eq!(b"Oh no, a typo!\n", output.stdout.as_slice());
59//! ```
60//!
61//! Note that [`ChildStderr`] and [`ChildStdout`] implement [`Read`] and
62//! [`ChildStdin`] implements [`Write`]:
63//!
64//! ```no_run
65//! use std::process::{Command, Stdio};
66//! use std::io::Write;
67//!
68//! let mut child = Command::new("/bin/cat")
69//! .stdin(Stdio::piped())
70//! .stdout(Stdio::piped())
71//! .spawn()
72//! .expect("failed to execute child");
73//!
74//! // If the child process fills its stdout buffer, it may end up
75//! // waiting until the parent reads the stdout, and not be able to
76//! // read stdin in the meantime, causing a deadlock.
77//! // Writing from another thread ensures that stdout is being read
78//! // at the same time, avoiding the problem.
79//! let mut stdin = child.stdin.take().expect("failed to get stdin");
80//! std::thread::spawn(move || {
81//! stdin.write_all(b"test").expect("failed to write to stdin");
82//! });
83//!
84//! let output = child
85//! .wait_with_output()
86//! .expect("failed to wait on child");
87//!
88//! assert_eq!(b"test", output.stdout.as_slice());
89//! ```
90//!
91//! # Windows argument splitting
92//!
93//! On Unix systems arguments are passed to a new process as an array of strings,
94//! but on Windows arguments are passed as a single commandline string and it is
95//! up to the child process to parse it into an array. Therefore the parent and
96//! child processes must agree on how the commandline string is encoded.
97//!
98//! Most programs use the standard C run-time `argv`, which in practice results
99//! in consistent argument handling. However, some programs have their own way of
100//! parsing the commandline string. In these cases using [`arg`] or [`args`] may
101//! result in the child process seeing a different array of arguments than the
102//! parent process intended.
103//!
104//! Two ways of mitigating this are:
105//!
106//! * Validate untrusted input so that only a safe subset is allowed.
107//! * Use [`raw_arg`] to build a custom commandline. This bypasses the escaping
108//! rules used by [`arg`] so should be used with due caution.
109//!
110//! `cmd.exe` and `.bat` files use non-standard argument parsing and are especially
111//! vulnerable to malicious input as they may be used to run arbitrary shell
112//! commands. Untrusted arguments should be restricted as much as possible.
113//! For examples on handling this see [`raw_arg`].
114//!
115//! ### Batch file special handling
116//!
117//! On Windows, `Command` uses the Windows API function [`CreateProcessW`] to
118//! spawn new processes. An undocumented feature of this function is that
119//! when given a `.bat` file as the application to run, it will automatically
120//! convert that into running `cmd.exe /c` with the batch file as the next argument.
121//!
122//! For historical reasons Rust currently preserves this behavior when using
123//! [`Command::new`], and escapes the arguments according to `cmd.exe` rules.
124//! Due to the complexity of `cmd.exe` argument handling, it might not be
125//! possible to safely escape some special characters, and using them will result
126//! in an error being returned at process spawn. The set of unescapeable
127//! special characters might change between releases.
128//!
129//! Also note that running batch scripts in this way may be removed in the
130//! future and so should not be relied upon.
131//!
132//! [`spawn`]: Command::spawn
133//! [`output`]: Command::output
134//!
135//! [`stdout`]: Command::stdout
136//! [`stdin`]: Command::stdin
137//! [`stderr`]: Command::stderr
138//!
139//! [`Write`]: io::Write
140//! [`Read`]: io::Read
141//!
142//! [`arg`]: Command::arg
143//! [`args`]: Command::args
144//! [`raw_arg`]: crate::os::windows::process::CommandExt::raw_arg
145//!
146//! [`CreateProcessW`]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw
147
148#![stable(feature = "process", since = "1.0.0")]
149#![deny(unsafe_op_in_unsafe_fn)]
150
151#[cfg(all(
152 test,
153 not(any(
154 target_os = "emscripten",
155 target_os = "wasi",
156 target_env = "sgx",
157 target_os = "xous",
158 target_os = "trusty",
159 ))
160))]
161mod tests;
162
163use crate::convert::Infallible;
164use crate::ffi::OsStr;
165use crate::io::prelude::*;
166use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut};
167use crate::num::NonZero;
168use crate::path::Path;
169use crate::sys::{AsInner, AsInnerMut, FromInner, IntoInner, process as imp};
170use crate::{fmt, format_args_nl, fs, str};
171
172/// Representation of a running or exited child process.
173///
174/// This structure is used to represent and manage child processes. A child
175/// process is created via the [`Command`] struct, which configures the
176/// spawning process and can itself be constructed using a builder-style
177/// interface.
178///
179/// There is no implementation of [`Drop`] for child processes,
180/// so if you do not ensure the `Child` has exited then it will continue to
181/// run, even after the `Child` handle to the child process has gone out of
182/// scope.
183///
184/// Calling [`wait`] (or other functions that wrap around it) will make
185/// the parent process wait until the child has actually exited before
186/// continuing.
187///
188/// # Warning
189///
190/// On some systems, calling [`wait`] or similar is necessary for the OS to
191/// release resources. A process that terminated but has not been waited on is
192/// still around as a "zombie". Leaving too many zombies around may exhaust
193/// global resources (for example process IDs).
194///
195/// The standard library does *not* automatically wait on child processes (not
196/// even if the `Child` is dropped), it is up to the application developer to do
197/// so. As a consequence, dropping `Child` handles without waiting on them first
198/// is not recommended in long-running applications.
199///
200/// # Examples
201///
202/// ```should_panic
203/// use std::process::Command;
204///
205/// let mut child = Command::new("/bin/cat")
206/// .arg("file.txt")
207/// .spawn()
208/// .expect("failed to execute child");
209///
210/// let ecode = child.wait().expect("failed to wait on child");
211///
212/// assert!(ecode.success());
213/// ```
214///
215/// [`wait`]: Child::wait
216#[stable(feature = "process", since = "1.0.0")]
217#[cfg_attr(not(test), rustc_diagnostic_item = "Child")]
218pub struct Child {
219 pub(crate) handle: imp::Process,
220
221 /// The handle for writing to the child's standard input (stdin), if it
222 /// has been captured. You might find it helpful to do
223 ///
224 /// ```ignore (incomplete)
225 /// let stdin = child.stdin.take().expect("handle present");
226 /// ```
227 ///
228 /// to avoid partially moving the `child` and thus blocking yourself from calling
229 /// functions on `child` while using `stdin`.
230 #[stable(feature = "process", since = "1.0.0")]
231 pub stdin: Option<ChildStdin>,
232
233 /// The handle for reading from the child's standard output (stdout), if it
234 /// has been captured. You might find it helpful to do
235 ///
236 /// ```ignore (incomplete)
237 /// let stdout = child.stdout.take().expect("handle present");
238 /// ```
239 ///
240 /// to avoid partially moving the `child` and thus blocking yourself from calling
241 /// functions on `child` while using `stdout`.
242 #[stable(feature = "process", since = "1.0.0")]
243 pub stdout: Option<ChildStdout>,
244
245 /// The handle for reading from the child's standard error (stderr), if it
246 /// has been captured. You might find it helpful to do
247 ///
248 /// ```ignore (incomplete)
249 /// let stderr = child.stderr.take().expect("handle present");
250 /// ```
251 ///
252 /// to avoid partially moving the `child` and thus blocking yourself from calling
253 /// functions on `child` while using `stderr`.
254 #[stable(feature = "process", since = "1.0.0")]
255 pub stderr: Option<ChildStderr>,
256}
257
258/// Allows extension traits within `std`.
259#[unstable(feature = "sealed", issue = "none")]
260impl crate::sealed::Sealed for Child {}
261
262impl AsInner<imp::Process> for Child {
263 #[inline]
264 fn as_inner(&self) -> &imp::Process {
265 &self.handle
266 }
267}
268
269impl FromInner<(imp::Process, StdioPipes)> for Child {
270 fn from_inner((handle, io: StdioPipes): (imp::Process, StdioPipes)) -> Child {
271 Child {
272 handle,
273 stdin: io.stdin.map(ChildStdin::from_inner),
274 stdout: io.stdout.map(ChildStdout::from_inner),
275 stderr: io.stderr.map(ChildStderr::from_inner),
276 }
277 }
278}
279
280impl IntoInner<imp::Process> for Child {
281 fn into_inner(self) -> imp::Process {
282 self.handle
283 }
284}
285
286#[stable(feature = "std_debug", since = "1.16.0")]
287impl fmt::Debug for Child {
288 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
289 f.debug_struct("Child")
290 .field("stdin", &self.stdin)
291 .field("stdout", &self.stdout)
292 .field("stderr", &self.stderr)
293 .finish_non_exhaustive()
294 }
295}
296
297/// The pipes connected to a spawned process.
298///
299/// Used to pass pipe handles between this module and [`imp`].
300pub(crate) struct StdioPipes {
301 pub stdin: Option<imp::ChildPipe>,
302 pub stdout: Option<imp::ChildPipe>,
303 pub stderr: Option<imp::ChildPipe>,
304}
305
306/// A handle to a child process's standard input (stdin).
307///
308/// This struct is used in the [`stdin`] field on [`Child`].
309///
310/// When an instance of `ChildStdin` is [dropped], the `ChildStdin`'s underlying
311/// file handle will be closed. If the child process was blocked on input prior
312/// to being dropped, it will become unblocked after dropping.
313///
314/// [`stdin`]: Child::stdin
315/// [dropped]: Drop
316#[stable(feature = "process", since = "1.0.0")]
317pub struct ChildStdin {
318 inner: imp::ChildPipe,
319}
320
321// In addition to the `impl`s here, `ChildStdin` also has `impl`s for
322// `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
323// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
324// `AsHandle`/`From<OwnedHandle>`/`Into<OwnedHandle>` and
325// `AsRawHandle`/`IntoRawHandle`/`FromRawHandle` on Windows.
326
327#[stable(feature = "process", since = "1.0.0")]
328impl Write for ChildStdin {
329 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
330 (&*self).write(buf)
331 }
332
333 fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
334 (&*self).write_vectored(bufs)
335 }
336
337 fn is_write_vectored(&self) -> bool {
338 io::Write::is_write_vectored(&&*self)
339 }
340
341 #[inline]
342 fn flush(&mut self) -> io::Result<()> {
343 (&*self).flush()
344 }
345}
346
347#[stable(feature = "write_mt", since = "1.48.0")]
348impl Write for &ChildStdin {
349 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
350 self.inner.write(buf)
351 }
352
353 fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
354 self.inner.write_vectored(bufs)
355 }
356
357 fn is_write_vectored(&self) -> bool {
358 self.inner.is_write_vectored()
359 }
360
361 #[inline]
362 fn flush(&mut self) -> io::Result<()> {
363 Ok(())
364 }
365}
366
367impl AsInner<imp::ChildPipe> for ChildStdin {
368 #[inline]
369 fn as_inner(&self) -> &imp::ChildPipe {
370 &self.inner
371 }
372}
373
374impl IntoInner<imp::ChildPipe> for ChildStdin {
375 fn into_inner(self) -> imp::ChildPipe {
376 self.inner
377 }
378}
379
380impl FromInner<imp::ChildPipe> for ChildStdin {
381 fn from_inner(pipe: imp::ChildPipe) -> ChildStdin {
382 ChildStdin { inner: pipe }
383 }
384}
385
386#[stable(feature = "std_debug", since = "1.16.0")]
387impl fmt::Debug for ChildStdin {
388 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
389 f.debug_struct("ChildStdin").finish_non_exhaustive()
390 }
391}
392
393/// A handle to a child process's standard output (stdout).
394///
395/// This struct is used in the [`stdout`] field on [`Child`].
396///
397/// When an instance of `ChildStdout` is [dropped], the `ChildStdout`'s
398/// underlying file handle will be closed.
399///
400/// [`stdout`]: Child::stdout
401/// [dropped]: Drop
402#[stable(feature = "process", since = "1.0.0")]
403pub struct ChildStdout {
404 inner: imp::ChildPipe,
405}
406
407// In addition to the `impl`s here, `ChildStdout` also has `impl`s for
408// `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
409// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
410// `AsHandle`/`From<OwnedHandle>`/`Into<OwnedHandle>` and
411// `AsRawHandle`/`IntoRawHandle`/`FromRawHandle` on Windows.
412
413#[stable(feature = "process", since = "1.0.0")]
414impl Read for ChildStdout {
415 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
416 self.inner.read(buf)
417 }
418
419 fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
420 self.inner.read_buf(buf)
421 }
422
423 fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
424 self.inner.read_vectored(bufs)
425 }
426
427 #[inline]
428 fn is_read_vectored(&self) -> bool {
429 self.inner.is_read_vectored()
430 }
431
432 fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
433 self.inner.read_to_end(buf)
434 }
435}
436
437impl AsInner<imp::ChildPipe> for ChildStdout {
438 #[inline]
439 fn as_inner(&self) -> &imp::ChildPipe {
440 &self.inner
441 }
442}
443
444impl IntoInner<imp::ChildPipe> for ChildStdout {
445 fn into_inner(self) -> imp::ChildPipe {
446 self.inner
447 }
448}
449
450impl FromInner<imp::ChildPipe> for ChildStdout {
451 fn from_inner(pipe: imp::ChildPipe) -> ChildStdout {
452 ChildStdout { inner: pipe }
453 }
454}
455
456#[stable(feature = "std_debug", since = "1.16.0")]
457impl fmt::Debug for ChildStdout {
458 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
459 f.debug_struct("ChildStdout").finish_non_exhaustive()
460 }
461}
462
463/// A handle to a child process's stderr.
464///
465/// This struct is used in the [`stderr`] field on [`Child`].
466///
467/// When an instance of `ChildStderr` is [dropped], the `ChildStderr`'s
468/// underlying file handle will be closed.
469///
470/// [`stderr`]: Child::stderr
471/// [dropped]: Drop
472#[stable(feature = "process", since = "1.0.0")]
473pub struct ChildStderr {
474 inner: imp::ChildPipe,
475}
476
477// In addition to the `impl`s here, `ChildStderr` also has `impl`s for
478// `AsFd`/`From<OwnedFd>`/`Into<OwnedFd>` and
479// `AsRawFd`/`IntoRawFd`/`FromRawFd`, on Unix and WASI, and
480// `AsHandle`/`From<OwnedHandle>`/`Into<OwnedHandle>` and
481// `AsRawHandle`/`IntoRawHandle`/`FromRawHandle` on Windows.
482
483#[stable(feature = "process", since = "1.0.0")]
484impl Read for ChildStderr {
485 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
486 self.inner.read(buf)
487 }
488
489 fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
490 self.inner.read_buf(buf)
491 }
492
493 fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
494 self.inner.read_vectored(bufs)
495 }
496
497 #[inline]
498 fn is_read_vectored(&self) -> bool {
499 self.inner.is_read_vectored()
500 }
501
502 fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
503 self.inner.read_to_end(buf)
504 }
505}
506
507impl AsInner<imp::ChildPipe> for ChildStderr {
508 #[inline]
509 fn as_inner(&self) -> &imp::ChildPipe {
510 &self.inner
511 }
512}
513
514impl IntoInner<imp::ChildPipe> for ChildStderr {
515 fn into_inner(self) -> imp::ChildPipe {
516 self.inner
517 }
518}
519
520impl FromInner<imp::ChildPipe> for ChildStderr {
521 fn from_inner(pipe: imp::ChildPipe) -> ChildStderr {
522 ChildStderr { inner: pipe }
523 }
524}
525
526#[stable(feature = "std_debug", since = "1.16.0")]
527impl fmt::Debug for ChildStderr {
528 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
529 f.debug_struct("ChildStderr").finish_non_exhaustive()
530 }
531}
532
533/// A process builder, providing fine-grained control
534/// over how a new process should be spawned.
535///
536/// A default configuration can be
537/// generated using `Command::new(program)`, where `program` gives a path to the
538/// program to be executed. Additional builder methods allow the configuration
539/// to be changed (for example, by adding arguments) prior to spawning:
540///
541/// ```
542/// # if cfg!(not(all(target_vendor = "apple", not(target_os = "macos")))) {
543/// use std::process::Command;
544///
545/// let output = if cfg!(target_os = "windows") {
546/// Command::new("cmd")
547/// .args(["/C", "echo hello"])
548/// .output()
549/// .expect("failed to execute process")
550/// } else {
551/// Command::new("sh")
552/// .arg("-c")
553/// .arg("echo hello")
554/// .output()
555/// .expect("failed to execute process")
556/// };
557///
558/// let hello = output.stdout;
559/// # }
560/// ```
561///
562/// `Command` can be reused to spawn multiple processes. The builder methods
563/// change the command without needing to immediately spawn the process.
564///
565/// ```no_run
566/// use std::process::Command;
567///
568/// let mut echo_hello = Command::new("sh");
569/// echo_hello.arg("-c").arg("echo hello");
570/// let hello_1 = echo_hello.output().expect("failed to execute process");
571/// let hello_2 = echo_hello.output().expect("failed to execute process");
572/// ```
573///
574/// Similarly, you can call builder methods after spawning a process and then
575/// spawn a new process with the modified settings.
576///
577/// ```no_run
578/// use std::process::Command;
579///
580/// let mut list_dir = Command::new("ls");
581///
582/// // Execute `ls` in the current directory of the program.
583/// list_dir.status().expect("process failed to execute");
584///
585/// println!();
586///
587/// // Change `ls` to execute in the root directory.
588/// list_dir.current_dir("/");
589///
590/// // And then execute `ls` again but in the root directory.
591/// list_dir.status().expect("process failed to execute");
592/// ```
593#[stable(feature = "process", since = "1.0.0")]
594#[cfg_attr(not(test), rustc_diagnostic_item = "Command")]
595pub struct Command {
596 inner: imp::Command,
597}
598
599/// Allows extension traits within `std`.
600#[unstable(feature = "sealed", issue = "none")]
601impl crate::sealed::Sealed for Command {}
602
603impl Command {
604 /// Constructs a new `Command` for launching the program at
605 /// path `program`, with the following default configuration:
606 ///
607 /// * No arguments to the program
608 /// * Inherit the current process's environment
609 /// * Inherit the current process's working directory
610 /// * Inherit stdin/stdout/stderr for [`spawn`] or [`status`], but create pipes for [`output`]
611 ///
612 /// [`spawn`]: Self::spawn
613 /// [`status`]: Self::status
614 /// [`output`]: Self::output
615 ///
616 /// Builder methods are provided to change these defaults and
617 /// otherwise configure the process.
618 ///
619 /// If `program` is not an absolute path, the `PATH` will be searched in
620 /// an OS-defined way.
621 ///
622 /// The search path to be used may be controlled by setting the
623 /// `PATH` environment variable on the Command,
624 /// but this has some implementation limitations on Windows
625 /// (see issue #37519).
626 ///
627 /// # Platform-specific behavior
628 ///
629 /// Note on Windows: For executable files with the .exe extension,
630 /// it can be omitted when specifying the program for this Command.
631 /// However, if the file has a different extension,
632 /// a filename including the extension needs to be provided,
633 /// otherwise the file won't be found.
634 ///
635 /// # Examples
636 ///
637 /// ```no_run
638 /// use std::process::Command;
639 ///
640 /// Command::new("sh")
641 /// .spawn()
642 /// .expect("sh command failed to start");
643 /// ```
644 ///
645 /// # Caveats
646 ///
647 /// [`Command::new`] is only intended to accept the path of the program. If you pass a program
648 /// path along with arguments like `Command::new("ls -l").spawn()`, it will try to search for
649 /// `ls -l` literally. The arguments need to be passed separately, such as via [`arg`] or
650 /// [`args`].
651 ///
652 /// ```no_run
653 /// use std::process::Command;
654 ///
655 /// Command::new("ls")
656 /// .arg("-l") // arg passed separately
657 /// .spawn()
658 /// .expect("ls command failed to start");
659 /// ```
660 ///
661 /// [`arg`]: Self::arg
662 /// [`args`]: Self::args
663 #[stable(feature = "process", since = "1.0.0")]
664 pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
665 Command { inner: imp::Command::new(program.as_ref()) }
666 }
667
668 /// Adds an argument to pass to the program.
669 ///
670 /// Only one argument can be passed per use. So instead of:
671 ///
672 /// ```no_run
673 /// # std::process::Command::new("sh")
674 /// .arg("-C /path/to/repo")
675 /// # ;
676 /// ```
677 ///
678 /// usage would be:
679 ///
680 /// ```no_run
681 /// # std::process::Command::new("sh")
682 /// .arg("-C")
683 /// .arg("/path/to/repo")
684 /// # ;
685 /// ```
686 ///
687 /// To pass multiple arguments see [`args`].
688 ///
689 /// [`args`]: Command::args
690 ///
691 /// Note that the argument is not passed through a shell, but given
692 /// literally to the program. This means that shell syntax like quotes,
693 /// escaped characters, word splitting, glob patterns, variable substitution,
694 /// etc. have no effect.
695 ///
696 /// <div class="warning">
697 ///
698 /// On Windows, use caution with untrusted inputs. Most applications use the
699 /// standard convention for decoding arguments passed to them. These are safe to
700 /// use with `arg`. However, some applications such as `cmd.exe` and `.bat` files
701 /// use a non-standard way of decoding arguments. They are therefore vulnerable
702 /// to malicious input.
703 ///
704 /// In the case of `cmd.exe` this is especially important because a malicious
705 /// argument can potentially run arbitrary shell commands.
706 ///
707 /// See [Windows argument splitting][windows-args] for more details
708 /// or [`raw_arg`] for manually implementing non-standard argument encoding.
709 ///
710 /// [`raw_arg`]: crate::os::windows::process::CommandExt::raw_arg
711 /// [windows-args]: crate::process#windows-argument-splitting
712 ///
713 /// </div>
714 ///
715 /// # Examples
716 ///
717 /// ```no_run
718 /// use std::process::Command;
719 ///
720 /// Command::new("ls")
721 /// .arg("-l")
722 /// .arg("-a")
723 /// .spawn()
724 /// .expect("ls command failed to start");
725 /// ```
726 #[stable(feature = "process", since = "1.0.0")]
727 pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Command {
728 self.inner.arg(arg.as_ref());
729 self
730 }
731
732 /// Adds multiple arguments to pass to the program.
733 ///
734 /// To pass a single argument see [`arg`].
735 ///
736 /// [`arg`]: Command::arg
737 ///
738 /// Note that the arguments are not passed through a shell, but given
739 /// literally to the program. This means that shell syntax like quotes,
740 /// escaped characters, word splitting, glob patterns, variable substitution, etc.
741 /// have no effect.
742 ///
743 /// <div class="warning">
744 ///
745 /// On Windows, use caution with untrusted inputs. Most applications use the
746 /// standard convention for decoding arguments passed to them. These are safe to
747 /// use with `arg`. However, some applications such as `cmd.exe` and `.bat` files
748 /// use a non-standard way of decoding arguments. They are therefore vulnerable
749 /// to malicious input.
750 ///
751 /// In the case of `cmd.exe` this is especially important because a malicious
752 /// argument can potentially run arbitrary shell commands.
753 ///
754 /// See [Windows argument splitting][windows-args] for more details
755 /// or [`raw_arg`] for manually implementing non-standard argument encoding.
756 ///
757 /// [`raw_arg`]: crate::os::windows::process::CommandExt::raw_arg
758 /// [windows-args]: crate::process#windows-argument-splitting
759 ///
760 /// </div>
761 ///
762 /// # Examples
763 ///
764 /// ```no_run
765 /// use std::process::Command;
766 ///
767 /// Command::new("ls")
768 /// .args(["-l", "-a"])
769 /// .spawn()
770 /// .expect("ls command failed to start");
771 /// ```
772 #[stable(feature = "process", since = "1.0.0")]
773 pub fn args<I, S>(&mut self, args: I) -> &mut Command
774 where
775 I: IntoIterator<Item = S>,
776 S: AsRef<OsStr>,
777 {
778 for arg in args {
779 self.arg(arg.as_ref());
780 }
781 self
782 }
783
784 /// Inserts or updates an explicit environment variable mapping.
785 ///
786 /// This method allows you to add an environment variable mapping to the spawned process or
787 /// overwrite a previously set value. You can use [`Command::envs`] to set multiple environment
788 /// variables simultaneously.
789 ///
790 /// Child processes will inherit environment variables from their parent process by default.
791 /// Environment variables explicitly set using [`Command::env`] take precedence over inherited
792 /// variables. You can disable environment variable inheritance entirely using
793 /// [`Command::env_clear`] or for a single key using [`Command::env_remove`].
794 ///
795 /// Note that environment variable names are case-insensitive (but
796 /// case-preserving) on Windows and case-sensitive on all other platforms.
797 ///
798 /// # Examples
799 ///
800 /// ```no_run
801 /// use std::process::Command;
802 ///
803 /// Command::new("ls")
804 /// .env("PATH", "/bin")
805 /// .spawn()
806 /// .expect("ls command failed to start");
807 /// ```
808 #[stable(feature = "process", since = "1.0.0")]
809 pub fn env<K, V>(&mut self, key: K, val: V) -> &mut Command
810 where
811 K: AsRef<OsStr>,
812 V: AsRef<OsStr>,
813 {
814 self.inner.env_mut().set(key.as_ref(), val.as_ref());
815 self
816 }
817
818 /// Inserts or updates multiple explicit environment variable mappings.
819 ///
820 /// This method allows you to add multiple environment variable mappings to the spawned process
821 /// or overwrite previously set values. You can use [`Command::env`] to set a single environment
822 /// variable.
823 ///
824 /// Child processes will inherit environment variables from their parent process by default.
825 /// Environment variables explicitly set using [`Command::envs`] take precedence over inherited
826 /// variables. You can disable environment variable inheritance entirely using
827 /// [`Command::env_clear`] or for a single key using [`Command::env_remove`].
828 ///
829 /// Note that environment variable names are case-insensitive (but case-preserving) on Windows
830 /// and case-sensitive on all other platforms.
831 ///
832 /// # Examples
833 ///
834 /// ```no_run
835 /// use std::process::{Command, Stdio};
836 /// use std::env;
837 /// use std::collections::HashMap;
838 ///
839 /// let filtered_env : HashMap<String, String> =
840 /// env::vars().filter(|&(ref k, _)|
841 /// k == "TERM" || k == "TZ" || k == "LANG" || k == "PATH"
842 /// ).collect();
843 ///
844 /// Command::new("printenv")
845 /// .stdin(Stdio::null())
846 /// .stdout(Stdio::inherit())
847 /// .env_clear()
848 /// .envs(&filtered_env)
849 /// .spawn()
850 /// .expect("printenv failed to start");
851 /// ```
852 #[stable(feature = "command_envs", since = "1.19.0")]
853 pub fn envs<I, K, V>(&mut self, vars: I) -> &mut Command
854 where
855 I: IntoIterator<Item = (K, V)>,
856 K: AsRef<OsStr>,
857 V: AsRef<OsStr>,
858 {
859 for (ref key, ref val) in vars {
860 self.inner.env_mut().set(key.as_ref(), val.as_ref());
861 }
862 self
863 }
864
865 /// Removes an explicitly set environment variable and prevents inheriting it from a parent
866 /// process.
867 ///
868 /// This method will remove the explicit value of an environment variable set via
869 /// [`Command::env`] or [`Command::envs`]. In addition, it will prevent the spawned child
870 /// process from inheriting that environment variable from its parent process.
871 ///
872 /// After calling [`Command::env_remove`], the value associated with its key from
873 /// [`Command::get_envs`] will be [`None`].
874 ///
875 /// To clear all explicitly set environment variables and disable all environment variable
876 /// inheritance, you can use [`Command::env_clear`].
877 ///
878 /// # Examples
879 ///
880 /// Prevent any inherited `GIT_DIR` variable from changing the target of the `git` command,
881 /// while allowing all other variables, like `GIT_AUTHOR_NAME`.
882 ///
883 /// ```no_run
884 /// use std::process::Command;
885 ///
886 /// Command::new("git")
887 /// .arg("commit")
888 /// .env_remove("GIT_DIR")
889 /// .spawn()?;
890 /// # std::io::Result::Ok(())
891 /// ```
892 #[stable(feature = "process", since = "1.0.0")]
893 pub fn env_remove<K: AsRef<OsStr>>(&mut self, key: K) -> &mut Command {
894 self.inner.env_mut().remove(key.as_ref());
895 self
896 }
897
898 /// Clears all explicitly set environment variables and prevents inheriting any parent process
899 /// environment variables.
900 ///
901 /// This method will remove all explicitly added environment variables set via [`Command::env`]
902 /// or [`Command::envs`]. In addition, it will prevent the spawned child process from inheriting
903 /// any environment variable from its parent process.
904 ///
905 /// After calling [`Command::env_clear`], the iterator from [`Command::get_envs`] will be
906 /// empty.
907 ///
908 /// You can use [`Command::env_remove`] to clear a single mapping.
909 ///
910 /// # Examples
911 ///
912 /// The behavior of `sort` is affected by `LANG` and `LC_*` environment variables.
913 /// Clearing the environment makes `sort`'s behavior independent of the parent processes' language.
914 ///
915 /// ```no_run
916 /// use std::process::Command;
917 ///
918 /// Command::new("sort")
919 /// .arg("file.txt")
920 /// .env_clear()
921 /// .spawn()?;
922 /// # std::io::Result::Ok(())
923 /// ```
924 #[stable(feature = "process", since = "1.0.0")]
925 pub fn env_clear(&mut self) -> &mut Command {
926 self.inner.env_mut().clear();
927 self
928 }
929
930 /// Sets the working directory for the child process.
931 ///
932 /// # Platform-specific behavior
933 ///
934 /// If the program path is relative (e.g., `"./script.sh"`), it's ambiguous
935 /// whether it should be interpreted relative to the parent's working
936 /// directory or relative to `current_dir`. The behavior in this case is
937 /// platform specific and unstable, and it's recommended to use
938 /// [`canonicalize`] to get an absolute program path instead.
939 ///
940 /// # Examples
941 ///
942 /// ```no_run
943 /// use std::process::Command;
944 ///
945 /// Command::new("ls")
946 /// .current_dir("/bin")
947 /// .spawn()
948 /// .expect("ls command failed to start");
949 /// ```
950 ///
951 /// [`canonicalize`]: crate::fs::canonicalize
952 #[stable(feature = "process", since = "1.0.0")]
953 pub fn current_dir<P: AsRef<Path>>(&mut self, dir: P) -> &mut Command {
954 self.inner.cwd(dir.as_ref().as_ref());
955 self
956 }
957
958 /// Configuration for the child process's standard input (stdin) handle.
959 ///
960 /// Defaults to [`inherit`] when used with [`spawn`] or [`status`], and
961 /// defaults to [`piped`] when used with [`output`].
962 ///
963 /// [`inherit`]: Stdio::inherit
964 /// [`piped`]: Stdio::piped
965 /// [`spawn`]: Self::spawn
966 /// [`status`]: Self::status
967 /// [`output`]: Self::output
968 ///
969 /// # Examples
970 ///
971 /// ```no_run
972 /// use std::process::{Command, Stdio};
973 ///
974 /// Command::new("ls")
975 /// .stdin(Stdio::null())
976 /// .spawn()
977 /// .expect("ls command failed to start");
978 /// ```
979 #[stable(feature = "process", since = "1.0.0")]
980 pub fn stdin<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Command {
981 self.inner.stdin(cfg.into().0);
982 self
983 }
984
985 /// Configuration for the child process's standard output (stdout) handle.
986 ///
987 /// Defaults to [`inherit`] when used with [`spawn`] or [`status`], and
988 /// defaults to [`piped`] when used with [`output`].
989 ///
990 /// [`inherit`]: Stdio::inherit
991 /// [`piped`]: Stdio::piped
992 /// [`spawn`]: Self::spawn
993 /// [`status`]: Self::status
994 /// [`output`]: Self::output
995 ///
996 /// # Examples
997 ///
998 /// ```no_run
999 /// use std::process::{Command, Stdio};
1000 ///
1001 /// Command::new("ls")
1002 /// .stdout(Stdio::null())
1003 /// .spawn()
1004 /// .expect("ls command failed to start");
1005 /// ```
1006 #[stable(feature = "process", since = "1.0.0")]
1007 pub fn stdout<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Command {
1008 self.inner.stdout(cfg.into().0);
1009 self
1010 }
1011
1012 /// Configuration for the child process's standard error (stderr) handle.
1013 ///
1014 /// Defaults to [`inherit`] when used with [`spawn`] or [`status`], and
1015 /// defaults to [`piped`] when used with [`output`].
1016 ///
1017 /// [`inherit`]: Stdio::inherit
1018 /// [`piped`]: Stdio::piped
1019 /// [`spawn`]: Self::spawn
1020 /// [`status`]: Self::status
1021 /// [`output`]: Self::output
1022 ///
1023 /// # Examples
1024 ///
1025 /// ```no_run
1026 /// use std::process::{Command, Stdio};
1027 ///
1028 /// Command::new("ls")
1029 /// .stderr(Stdio::null())
1030 /// .spawn()
1031 /// .expect("ls command failed to start");
1032 /// ```
1033 #[stable(feature = "process", since = "1.0.0")]
1034 pub fn stderr<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Command {
1035 self.inner.stderr(cfg.into().0);
1036 self
1037 }
1038
1039 /// Executes the command as a child process, returning a handle to it.
1040 ///
1041 /// By default, stdin, stdout and stderr are inherited from the parent.
1042 ///
1043 /// # Examples
1044 ///
1045 /// ```no_run
1046 /// use std::process::Command;
1047 ///
1048 /// Command::new("ls")
1049 /// .spawn()
1050 /// .expect("ls command failed to start");
1051 /// ```
1052 #[stable(feature = "process", since = "1.0.0")]
1053 pub fn spawn(&mut self) -> io::Result<Child> {
1054 self.inner.spawn(imp::Stdio::Inherit, true).map(Child::from_inner)
1055 }
1056
1057 /// Executes the command as a child process, waiting for it to finish and
1058 /// collecting all of its output.
1059 ///
1060 /// By default, stdout and stderr are captured (and used to provide the
1061 /// resulting output). Stdin is not inherited from the parent and any
1062 /// attempt by the child process to read from the stdin stream will result
1063 /// in the stream immediately closing.
1064 ///
1065 /// # Examples
1066 ///
1067 /// ```should_panic
1068 /// use std::process::Command;
1069 /// use std::io::{self, Write};
1070 /// let output = Command::new("/bin/cat")
1071 /// .arg("file.txt")
1072 /// .output()?;
1073 ///
1074 /// println!("status: {}", output.status);
1075 /// io::stdout().write_all(&output.stdout)?;
1076 /// io::stderr().write_all(&output.stderr)?;
1077 ///
1078 /// assert!(output.status.success());
1079 /// # io::Result::Ok(())
1080 /// ```
1081 #[stable(feature = "process", since = "1.0.0")]
1082 pub fn output(&mut self) -> io::Result<Output> {
1083 let (status, stdout, stderr) = imp::output(&mut self.inner)?;
1084 Ok(Output { status: ExitStatus(status), stdout, stderr })
1085 }
1086
1087 /// Executes a command as a child process, waiting for it to finish and
1088 /// collecting its status.
1089 ///
1090 /// By default, stdin, stdout and stderr are inherited from the parent.
1091 ///
1092 /// # Examples
1093 ///
1094 /// ```should_panic
1095 /// use std::process::Command;
1096 ///
1097 /// let status = Command::new("/bin/cat")
1098 /// .arg("file.txt")
1099 /// .status()
1100 /// .expect("failed to execute process");
1101 ///
1102 /// println!("process finished with: {status}");
1103 ///
1104 /// assert!(status.success());
1105 /// ```
1106 #[stable(feature = "process", since = "1.0.0")]
1107 pub fn status(&mut self) -> io::Result<ExitStatus> {
1108 self.inner
1109 .spawn(imp::Stdio::Inherit, true)
1110 .map(Child::from_inner)
1111 .and_then(|mut p| p.wait())
1112 }
1113
1114 /// Returns the path to the program that was given to [`Command::new`].
1115 ///
1116 /// # Examples
1117 ///
1118 /// ```
1119 /// use std::process::Command;
1120 ///
1121 /// let cmd = Command::new("echo");
1122 /// assert_eq!(cmd.get_program(), "echo");
1123 /// ```
1124 #[must_use]
1125 #[stable(feature = "command_access", since = "1.57.0")]
1126 pub fn get_program(&self) -> &OsStr {
1127 self.inner.get_program()
1128 }
1129
1130 /// Returns an iterator of the arguments that will be passed to the program.
1131 ///
1132 /// This does not include the path to the program as the first argument;
1133 /// it only includes the arguments specified with [`Command::arg`] and
1134 /// [`Command::args`].
1135 ///
1136 /// # Examples
1137 ///
1138 /// ```
1139 /// use std::ffi::OsStr;
1140 /// use std::process::Command;
1141 ///
1142 /// let mut cmd = Command::new("echo");
1143 /// cmd.arg("first").arg("second");
1144 /// let args: Vec<&OsStr> = cmd.get_args().collect();
1145 /// assert_eq!(args, &["first", "second"]);
1146 /// ```
1147 #[stable(feature = "command_access", since = "1.57.0")]
1148 pub fn get_args(&self) -> CommandArgs<'_> {
1149 CommandArgs { inner: self.inner.get_args() }
1150 }
1151
1152 /// Returns an iterator of the environment variables explicitly set for the child process.
1153 ///
1154 /// Environment variables explicitly set using [`Command::env`], [`Command::envs`], and
1155 /// [`Command::env_remove`] can be retrieved with this method.
1156 ///
1157 /// Note that this output does not include environment variables inherited from the parent
1158 /// process.
1159 ///
1160 /// Each element is a tuple key/value pair `(&OsStr, Option<&OsStr>)`. A [`None`] value
1161 /// indicates its key was explicitly removed via [`Command::env_remove`]. The associated key for
1162 /// the [`None`] value will no longer inherit from its parent process.
1163 ///
1164 /// An empty iterator can indicate that no explicit mappings were added or that
1165 /// [`Command::env_clear`] was called. After calling [`Command::env_clear`], the child process
1166 /// will not inherit any environment variables from its parent process.
1167 ///
1168 /// # Examples
1169 ///
1170 /// ```
1171 /// use std::ffi::OsStr;
1172 /// use std::process::Command;
1173 ///
1174 /// let mut cmd = Command::new("ls");
1175 /// cmd.env("TERM", "dumb").env_remove("TZ");
1176 /// let envs: Vec<(&OsStr, Option<&OsStr>)> = cmd.get_envs().collect();
1177 /// assert_eq!(envs, &[
1178 /// (OsStr::new("TERM"), Some(OsStr::new("dumb"))),
1179 /// (OsStr::new("TZ"), None)
1180 /// ]);
1181 /// ```
1182 #[stable(feature = "command_access", since = "1.57.0")]
1183 pub fn get_envs(&self) -> CommandEnvs<'_> {
1184 CommandEnvs { iter: self.inner.get_envs() }
1185 }
1186
1187 /// Returns the working directory for the child process.
1188 ///
1189 /// This returns [`None`] if the working directory will not be changed.
1190 ///
1191 /// # Examples
1192 ///
1193 /// ```
1194 /// use std::path::Path;
1195 /// use std::process::Command;
1196 ///
1197 /// let mut cmd = Command::new("ls");
1198 /// assert_eq!(cmd.get_current_dir(), None);
1199 /// cmd.current_dir("/bin");
1200 /// assert_eq!(cmd.get_current_dir(), Some(Path::new("/bin")));
1201 /// ```
1202 #[must_use]
1203 #[stable(feature = "command_access", since = "1.57.0")]
1204 pub fn get_current_dir(&self) -> Option<&Path> {
1205 self.inner.get_current_dir()
1206 }
1207
1208 /// Returns whether the environment will be cleared for the child process.
1209 ///
1210 /// This returns `true` if [`Command::env_clear`] was called, and `false` otherwise.
1211 /// When `true`, the child process will not inherit any environment variables from
1212 /// its parent process.
1213 ///
1214 /// # Examples
1215 ///
1216 /// ```
1217 /// #![feature(command_resolved_envs)]
1218 /// use std::process::Command;
1219 ///
1220 /// let mut cmd = Command::new("ls");
1221 /// assert_eq!(cmd.get_env_clear(), false);
1222 ///
1223 /// cmd.env_clear();
1224 /// assert_eq!(cmd.get_env_clear(), true);
1225 /// ```
1226 #[must_use]
1227 #[unstable(feature = "command_resolved_envs", issue = "149070")]
1228 pub fn get_env_clear(&self) -> bool {
1229 self.inner.get_env_clear()
1230 }
1231}
1232
1233#[stable(feature = "rust1", since = "1.0.0")]
1234impl fmt::Debug for Command {
1235 /// Format the program and arguments of a Command for display. Any
1236 /// non-utf8 data is lossily converted using the utf8 replacement
1237 /// character.
1238 ///
1239 /// The default format approximates a shell invocation of the program along with its
1240 /// arguments. It does not include most of the other command properties. The output is not guaranteed to work
1241 /// (e.g. due to lack of shell-escaping or differences in path resolution).
1242 /// On some platforms you can use [the alternate syntax] to show more fields.
1243 ///
1244 /// Note that the debug implementation is platform-specific.
1245 ///
1246 /// [the alternate syntax]: fmt#sign0
1247 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1248 self.inner.fmt(f)
1249 }
1250}
1251
1252impl AsInner<imp::Command> for Command {
1253 #[inline]
1254 fn as_inner(&self) -> &imp::Command {
1255 &self.inner
1256 }
1257}
1258
1259impl AsInnerMut<imp::Command> for Command {
1260 #[inline]
1261 fn as_inner_mut(&mut self) -> &mut imp::Command {
1262 &mut self.inner
1263 }
1264}
1265
1266/// An iterator over the command arguments.
1267///
1268/// This struct is created by [`Command::get_args`]. See its documentation for
1269/// more.
1270#[must_use = "iterators are lazy and do nothing unless consumed"]
1271#[stable(feature = "command_access", since = "1.57.0")]
1272#[derive(Debug)]
1273pub struct CommandArgs<'a> {
1274 inner: imp::CommandArgs<'a>,
1275}
1276
1277#[stable(feature = "command_access", since = "1.57.0")]
1278impl<'a> Iterator for CommandArgs<'a> {
1279 type Item = &'a OsStr;
1280 fn next(&mut self) -> Option<&'a OsStr> {
1281 self.inner.next()
1282 }
1283 fn size_hint(&self) -> (usize, Option<usize>) {
1284 self.inner.size_hint()
1285 }
1286}
1287
1288#[stable(feature = "command_access", since = "1.57.0")]
1289impl<'a> ExactSizeIterator for CommandArgs<'a> {
1290 fn len(&self) -> usize {
1291 self.inner.len()
1292 }
1293 fn is_empty(&self) -> bool {
1294 self.inner.is_empty()
1295 }
1296}
1297
1298/// An iterator over the command environment variables.
1299///
1300/// This struct is created by
1301/// [`Command::get_envs`][crate::process::Command::get_envs]. See its
1302/// documentation for more.
1303#[must_use = "iterators are lazy and do nothing unless consumed"]
1304#[stable(feature = "command_access", since = "1.57.0")]
1305pub struct CommandEnvs<'a> {
1306 iter: imp::CommandEnvs<'a>,
1307}
1308
1309#[stable(feature = "command_access", since = "1.57.0")]
1310impl<'a> Iterator for CommandEnvs<'a> {
1311 type Item = (&'a OsStr, Option<&'a OsStr>);
1312
1313 fn next(&mut self) -> Option<Self::Item> {
1314 self.iter.next()
1315 }
1316
1317 fn size_hint(&self) -> (usize, Option<usize>) {
1318 self.iter.size_hint()
1319 }
1320}
1321
1322#[stable(feature = "command_access", since = "1.57.0")]
1323impl<'a> ExactSizeIterator for CommandEnvs<'a> {
1324 fn len(&self) -> usize {
1325 self.iter.len()
1326 }
1327
1328 fn is_empty(&self) -> bool {
1329 self.iter.is_empty()
1330 }
1331}
1332
1333#[stable(feature = "command_access", since = "1.57.0")]
1334impl<'a> fmt::Debug for CommandEnvs<'a> {
1335 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1336 self.iter.fmt(f)
1337 }
1338}
1339
1340/// The output of a finished process.
1341///
1342/// This is returned in a Result by either the [`output`] method of a
1343/// [`Command`], or the [`wait_with_output`] method of a [`Child`]
1344/// process.
1345///
1346/// [`output`]: Command::output
1347/// [`wait_with_output`]: Child::wait_with_output
1348#[derive(PartialEq, Eq, Clone)]
1349#[stable(feature = "process", since = "1.0.0")]
1350pub struct Output {
1351 /// The status (exit code) of the process.
1352 #[stable(feature = "process", since = "1.0.0")]
1353 pub status: ExitStatus,
1354 /// The data that the process wrote to stdout.
1355 #[stable(feature = "process", since = "1.0.0")]
1356 pub stdout: Vec<u8>,
1357 /// The data that the process wrote to stderr.
1358 #[stable(feature = "process", since = "1.0.0")]
1359 pub stderr: Vec<u8>,
1360}
1361
1362impl Output {
1363 /// Returns an error if a nonzero exit status was received.
1364 ///
1365 /// If the [`Command`] exited successfully,
1366 /// `self` is returned.
1367 ///
1368 /// This is equivalent to calling [`exit_ok`](ExitStatus::exit_ok)
1369 /// on [`Output.status`](Output::status).
1370 ///
1371 /// Note that this will throw away the [`Output::stderr`] field in the error case.
1372 /// If the child process outputs useful informantion to stderr, you can:
1373 /// * Use `cmd.stderr(Stdio::inherit())` to forward the
1374 /// stderr child process to the parent's stderr,
1375 /// usually printing it to console where the user can see it.
1376 /// This is usually correct for command-line applications.
1377 /// * Capture `stderr` using a custom error type.
1378 /// This is usually correct for libraries.
1379 ///
1380 /// # Examples
1381 ///
1382 /// ```
1383 /// #![feature(exit_status_error)]
1384 /// # #[cfg(all(unix, not(target_os = "android"), not(all(target_vendor = "apple", not(target_os = "macos")))))] {
1385 /// use std::process::Command;
1386 /// assert!(Command::new("false").output().unwrap().exit_ok().is_err());
1387 /// # }
1388 /// ```
1389 #[unstable(feature = "exit_status_error", issue = "84908")]
1390 pub fn exit_ok(self) -> Result<Self, ExitStatusError> {
1391 self.status.exit_ok()?;
1392 Ok(self)
1393 }
1394}
1395
1396// If either stderr or stdout are valid utf8 strings it prints the valid
1397// strings, otherwise it prints the byte sequence instead
1398#[stable(feature = "process_output_debug", since = "1.7.0")]
1399impl fmt::Debug for Output {
1400 fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
1401 let stdout_utf8 = str::from_utf8(&self.stdout);
1402 let stdout_debug: &dyn fmt::Debug = match stdout_utf8 {
1403 Ok(ref s: &{unknown}) => s,
1404 Err(_) => &self.stdout,
1405 };
1406
1407 let stderr_utf8 = str::from_utf8(&self.stderr);
1408 let stderr_debug: &dyn fmt::Debug = match stderr_utf8 {
1409 Ok(ref s: &{unknown}) => s,
1410 Err(_) => &self.stderr,
1411 };
1412
1413 fmt.debug_struct("Output")
1414 .field("status", &self.status)
1415 .field("stdout", stdout_debug)
1416 .field("stderr", stderr_debug)
1417 .finish()
1418 }
1419}
1420
1421/// Describes what to do with a standard I/O stream for a child process when
1422/// passed to the [`stdin`], [`stdout`], and [`stderr`] methods of [`Command`].
1423///
1424/// [`stdin`]: Command::stdin
1425/// [`stdout`]: Command::stdout
1426/// [`stderr`]: Command::stderr
1427#[stable(feature = "process", since = "1.0.0")]
1428pub struct Stdio(imp::Stdio);
1429
1430impl Stdio {
1431 /// A new pipe should be arranged to connect the parent and child processes.
1432 ///
1433 /// # Examples
1434 ///
1435 /// With stdout:
1436 ///
1437 /// ```no_run
1438 /// use std::process::{Command, Stdio};
1439 ///
1440 /// let output = Command::new("echo")
1441 /// .arg("Hello, world!")
1442 /// .stdout(Stdio::piped())
1443 /// .output()
1444 /// .expect("Failed to execute command");
1445 ///
1446 /// assert_eq!(String::from_utf8_lossy(&output.stdout), "Hello, world!\n");
1447 /// // Nothing echoed to console
1448 /// ```
1449 ///
1450 /// With stdin:
1451 ///
1452 /// ```no_run
1453 /// use std::io::Write;
1454 /// use std::process::{Command, Stdio};
1455 ///
1456 /// let mut child = Command::new("rev")
1457 /// .stdin(Stdio::piped())
1458 /// .stdout(Stdio::piped())
1459 /// .spawn()
1460 /// .expect("Failed to spawn child process");
1461 ///
1462 /// let mut stdin = child.stdin.take().expect("Failed to open stdin");
1463 /// std::thread::spawn(move || {
1464 /// stdin.write_all("Hello, world!".as_bytes()).expect("Failed to write to stdin");
1465 /// });
1466 ///
1467 /// let output = child.wait_with_output().expect("Failed to read stdout");
1468 /// assert_eq!(String::from_utf8_lossy(&output.stdout), "!dlrow ,olleH");
1469 /// ```
1470 ///
1471 /// Writing more than a pipe buffer's worth of input to stdin without also reading
1472 /// stdout and stderr at the same time may cause a deadlock.
1473 /// This is an issue when running any program that doesn't guarantee that it reads
1474 /// its entire stdin before writing more than a pipe buffer's worth of output.
1475 /// The size of a pipe buffer varies on different targets.
1476 ///
1477 #[must_use]
1478 #[stable(feature = "process", since = "1.0.0")]
1479 pub fn piped() -> Stdio {
1480 Stdio(imp::Stdio::MakePipe)
1481 }
1482
1483 /// The child inherits from the corresponding parent descriptor.
1484 ///
1485 /// # Examples
1486 ///
1487 /// With stdout:
1488 ///
1489 /// ```no_run
1490 /// use std::process::{Command, Stdio};
1491 ///
1492 /// let output = Command::new("echo")
1493 /// .arg("Hello, world!")
1494 /// .stdout(Stdio::inherit())
1495 /// .output()
1496 /// .expect("Failed to execute command");
1497 ///
1498 /// assert_eq!(String::from_utf8_lossy(&output.stdout), "");
1499 /// // "Hello, world!" echoed to console
1500 /// ```
1501 ///
1502 /// With stdin:
1503 ///
1504 /// ```no_run
1505 /// use std::process::{Command, Stdio};
1506 /// use std::io::{self, Write};
1507 ///
1508 /// let output = Command::new("rev")
1509 /// .stdin(Stdio::inherit())
1510 /// .stdout(Stdio::piped())
1511 /// .output()?;
1512 ///
1513 /// print!("You piped in the reverse of: ");
1514 /// io::stdout().write_all(&output.stdout)?;
1515 /// # io::Result::Ok(())
1516 /// ```
1517 #[must_use]
1518 #[stable(feature = "process", since = "1.0.0")]
1519 pub fn inherit() -> Stdio {
1520 Stdio(imp::Stdio::Inherit)
1521 }
1522
1523 /// This stream will be ignored. This is the equivalent of attaching the
1524 /// stream to `/dev/null`.
1525 ///
1526 /// # Examples
1527 ///
1528 /// With stdout:
1529 ///
1530 /// ```no_run
1531 /// use std::process::{Command, Stdio};
1532 ///
1533 /// let output = Command::new("echo")
1534 /// .arg("Hello, world!")
1535 /// .stdout(Stdio::null())
1536 /// .output()
1537 /// .expect("Failed to execute command");
1538 ///
1539 /// assert_eq!(String::from_utf8_lossy(&output.stdout), "");
1540 /// // Nothing echoed to console
1541 /// ```
1542 ///
1543 /// With stdin:
1544 ///
1545 /// ```no_run
1546 /// use std::process::{Command, Stdio};
1547 ///
1548 /// let output = Command::new("rev")
1549 /// .stdin(Stdio::null())
1550 /// .stdout(Stdio::piped())
1551 /// .output()
1552 /// .expect("Failed to execute command");
1553 ///
1554 /// assert_eq!(String::from_utf8_lossy(&output.stdout), "");
1555 /// // Ignores any piped-in input
1556 /// ```
1557 #[must_use]
1558 #[stable(feature = "process", since = "1.0.0")]
1559 pub fn null() -> Stdio {
1560 Stdio(imp::Stdio::Null)
1561 }
1562
1563 /// Returns `true` if this requires [`Command`] to create a new pipe.
1564 ///
1565 /// # Example
1566 ///
1567 /// ```
1568 /// #![feature(stdio_makes_pipe)]
1569 /// use std::process::Stdio;
1570 ///
1571 /// let io = Stdio::piped();
1572 /// assert_eq!(io.makes_pipe(), true);
1573 /// ```
1574 #[unstable(feature = "stdio_makes_pipe", issue = "98288")]
1575 pub fn makes_pipe(&self) -> bool {
1576 matches!(self.0, imp::Stdio::MakePipe)
1577 }
1578}
1579
1580impl FromInner<imp::Stdio> for Stdio {
1581 fn from_inner(inner: imp::Stdio) -> Stdio {
1582 Stdio(inner)
1583 }
1584}
1585
1586#[stable(feature = "std_debug", since = "1.16.0")]
1587impl fmt::Debug for Stdio {
1588 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1589 f.debug_struct("Stdio").finish_non_exhaustive()
1590 }
1591}
1592
1593#[stable(feature = "stdio_from", since = "1.20.0")]
1594impl From<ChildStdin> for Stdio {
1595 /// Converts a [`ChildStdin`] into a [`Stdio`].
1596 ///
1597 /// # Examples
1598 ///
1599 /// `ChildStdin` will be converted to `Stdio` using `Stdio::from` under the hood.
1600 ///
1601 /// ```rust,no_run
1602 /// use std::process::{Command, Stdio};
1603 ///
1604 /// let reverse = Command::new("rev")
1605 /// .stdin(Stdio::piped())
1606 /// .spawn()
1607 /// .expect("failed reverse command");
1608 ///
1609 /// let _echo = Command::new("echo")
1610 /// .arg("Hello, world!")
1611 /// .stdout(reverse.stdin.unwrap()) // Converted into a Stdio here
1612 /// .output()
1613 /// .expect("failed echo command");
1614 ///
1615 /// // "!dlrow ,olleH" echoed to console
1616 /// ```
1617 fn from(child: ChildStdin) -> Stdio {
1618 Stdio::from_inner(child.into_inner().into())
1619 }
1620}
1621
1622#[stable(feature = "stdio_from", since = "1.20.0")]
1623impl From<ChildStdout> for Stdio {
1624 /// Converts a [`ChildStdout`] into a [`Stdio`].
1625 ///
1626 /// # Examples
1627 ///
1628 /// `ChildStdout` will be converted to `Stdio` using `Stdio::from` under the hood.
1629 ///
1630 /// ```rust,no_run
1631 /// use std::process::{Command, Stdio};
1632 ///
1633 /// let hello = Command::new("echo")
1634 /// .arg("Hello, world!")
1635 /// .stdout(Stdio::piped())
1636 /// .spawn()
1637 /// .expect("failed echo command");
1638 ///
1639 /// let reverse = Command::new("rev")
1640 /// .stdin(hello.stdout.unwrap()) // Converted into a Stdio here
1641 /// .output()
1642 /// .expect("failed reverse command");
1643 ///
1644 /// assert_eq!(reverse.stdout, b"!dlrow ,olleH\n");
1645 /// ```
1646 fn from(child: ChildStdout) -> Stdio {
1647 Stdio::from_inner(child.into_inner().into())
1648 }
1649}
1650
1651#[stable(feature = "stdio_from", since = "1.20.0")]
1652impl From<ChildStderr> for Stdio {
1653 /// Converts a [`ChildStderr`] into a [`Stdio`].
1654 ///
1655 /// # Examples
1656 ///
1657 /// ```rust,no_run
1658 /// use std::process::{Command, Stdio};
1659 ///
1660 /// let reverse = Command::new("rev")
1661 /// .arg("non_existing_file.txt")
1662 /// .stderr(Stdio::piped())
1663 /// .spawn()
1664 /// .expect("failed reverse command");
1665 ///
1666 /// let cat = Command::new("cat")
1667 /// .arg("-")
1668 /// .stdin(reverse.stderr.unwrap()) // Converted into a Stdio here
1669 /// .output()
1670 /// .expect("failed echo command");
1671 ///
1672 /// assert_eq!(
1673 /// String::from_utf8_lossy(&cat.stdout),
1674 /// "rev: cannot open non_existing_file.txt: No such file or directory\n"
1675 /// );
1676 /// ```
1677 fn from(child: ChildStderr) -> Stdio {
1678 Stdio::from_inner(child.into_inner().into())
1679 }
1680}
1681
1682#[stable(feature = "stdio_from", since = "1.20.0")]
1683impl From<fs::File> for Stdio {
1684 /// Converts a [`File`](fs::File) into a [`Stdio`].
1685 ///
1686 /// # Examples
1687 ///
1688 /// `File` will be converted to `Stdio` using `Stdio::from` under the hood.
1689 ///
1690 /// ```rust,no_run
1691 /// use std::fs::File;
1692 /// use std::process::Command;
1693 ///
1694 /// // With the `foo.txt` file containing "Hello, world!"
1695 /// let file = File::open("foo.txt")?;
1696 ///
1697 /// let reverse = Command::new("rev")
1698 /// .stdin(file) // Implicit File conversion into a Stdio
1699 /// .output()?;
1700 ///
1701 /// assert_eq!(reverse.stdout, b"!dlrow ,olleH");
1702 /// # std::io::Result::Ok(())
1703 /// ```
1704 fn from(file: fs::File) -> Stdio {
1705 Stdio::from_inner(file.into_inner().into())
1706 }
1707}
1708
1709#[stable(feature = "stdio_from_stdio", since = "1.74.0")]
1710impl From<io::Stdout> for Stdio {
1711 /// Redirect command stdout/stderr to our stdout
1712 ///
1713 /// # Examples
1714 ///
1715 /// ```rust
1716 /// #![feature(exit_status_error)]
1717 /// use std::io;
1718 /// use std::process::Command;
1719 ///
1720 /// # fn test() -> Result<(), Box<dyn std::error::Error>> {
1721 /// let output = Command::new("whoami")
1722 // "whoami" is a command which exists on both Unix and Windows,
1723 // and which succeeds, producing some stdout output but no stderr.
1724 /// .stdout(io::stdout())
1725 /// .output()?;
1726 /// output.status.exit_ok()?;
1727 /// assert!(output.stdout.is_empty());
1728 /// # Ok(())
1729 /// # }
1730 /// #
1731 /// # if cfg!(all(unix, not(target_os = "android"), not(all(target_vendor = "apple", not(target_os = "macos"))))) {
1732 /// # test().unwrap();
1733 /// # }
1734 /// ```
1735 fn from(inherit: io::Stdout) -> Stdio {
1736 Stdio::from_inner(inherit.into())
1737 }
1738}
1739
1740#[stable(feature = "stdio_from_stdio", since = "1.74.0")]
1741impl From<io::Stderr> for Stdio {
1742 /// Redirect command stdout/stderr to our stderr
1743 ///
1744 /// # Examples
1745 ///
1746 /// ```rust
1747 /// #![feature(exit_status_error)]
1748 /// use std::io;
1749 /// use std::process::Command;
1750 ///
1751 /// # fn test() -> Result<(), Box<dyn std::error::Error>> {
1752 /// let output = Command::new("whoami")
1753 /// .stdout(io::stderr())
1754 /// .output()?;
1755 /// output.status.exit_ok()?;
1756 /// assert!(output.stdout.is_empty());
1757 /// # Ok(())
1758 /// # }
1759 /// #
1760 /// # if cfg!(all(unix, not(target_os = "android"), not(all(target_vendor = "apple", not(target_os = "macos"))))) {
1761 /// # test().unwrap();
1762 /// # }
1763 /// ```
1764 fn from(inherit: io::Stderr) -> Stdio {
1765 Stdio::from_inner(inherit.into())
1766 }
1767}
1768
1769#[stable(feature = "anonymous_pipe", since = "1.87.0")]
1770impl From<io::PipeWriter> for Stdio {
1771 fn from(pipe: io::PipeWriter) -> Self {
1772 Stdio::from_inner(pipe.into_inner().into())
1773 }
1774}
1775
1776#[stable(feature = "anonymous_pipe", since = "1.87.0")]
1777impl From<io::PipeReader> for Stdio {
1778 fn from(pipe: io::PipeReader) -> Self {
1779 Stdio::from_inner(pipe.into_inner().into())
1780 }
1781}
1782
1783/// Describes the result of a process after it has terminated.
1784///
1785/// This `struct` is used to represent the exit status or other termination of a child process.
1786/// Child processes are created via the [`Command`] struct and their exit
1787/// status is exposed through the [`status`] method, or the [`wait`] method
1788/// of a [`Child`] process.
1789///
1790/// An `ExitStatus` represents every possible disposition of a process. On Unix this
1791/// is the **wait status**. It is *not* simply an *exit status* (a value passed to `exit`).
1792///
1793/// For proper error reporting of failed processes, print the value of `ExitStatus` or
1794/// `ExitStatusError` using their implementations of [`Display`](crate::fmt::Display).
1795///
1796/// # Differences from `ExitCode`
1797///
1798/// [`ExitCode`] is intended for terminating the currently running process, via
1799/// the `Termination` trait, in contrast to `ExitStatus`, which represents the
1800/// termination of a child process. These APIs are separate due to platform
1801/// compatibility differences and their expected usage; it is not generally
1802/// possible to exactly reproduce an `ExitStatus` from a child for the current
1803/// process after the fact.
1804///
1805/// [`status`]: Command::status
1806/// [`wait`]: Child::wait
1807//
1808// We speak slightly loosely (here and in various other places in the stdlib docs) about `exit`
1809// vs `_exit`. Naming of Unix system calls is not standardised across Unices, so terminology is a
1810// matter of convention and tradition. For clarity we usually speak of `exit`, even when we might
1811// mean an underlying system call such as `_exit`.
1812#[derive(PartialEq, Eq, Clone, Copy, Debug)]
1813#[stable(feature = "process", since = "1.0.0")]
1814pub struct ExitStatus(imp::ExitStatus);
1815
1816/// The default value is one which indicates successful completion.
1817#[stable(feature = "process_exitstatus_default", since = "1.73.0")]
1818impl Default for ExitStatus {
1819 fn default() -> Self {
1820 // Ideally this would be done by ExitCode::default().into() but that is complicated.
1821 ExitStatus::from_inner(imp::ExitStatus::default())
1822 }
1823}
1824
1825/// Allows extension traits within `std`.
1826#[unstable(feature = "sealed", issue = "none")]
1827impl crate::sealed::Sealed for ExitStatus {}
1828
1829impl ExitStatus {
1830 /// Was termination successful? Returns a `Result`.
1831 ///
1832 /// # Examples
1833 ///
1834 /// ```
1835 /// #![feature(exit_status_error)]
1836 /// # if cfg!(all(unix, not(all(target_vendor = "apple", not(target_os = "macos"))))) {
1837 /// use std::process::Command;
1838 ///
1839 /// let status = Command::new("ls")
1840 /// .arg("/dev/nonexistent")
1841 /// .status()
1842 /// .expect("ls could not be executed");
1843 ///
1844 /// println!("ls: {status}");
1845 /// status.exit_ok().expect_err("/dev/nonexistent could be listed!");
1846 /// # } // cfg!(unix)
1847 /// ```
1848 #[unstable(feature = "exit_status_error", issue = "84908")]
1849 pub fn exit_ok(&self) -> Result<(), ExitStatusError> {
1850 self.0.exit_ok().map_err(ExitStatusError)
1851 }
1852
1853 /// Was termination successful? Signal termination is not considered a
1854 /// success, and success is defined as a zero exit status.
1855 ///
1856 /// # Examples
1857 ///
1858 /// ```rust,no_run
1859 /// use std::process::Command;
1860 ///
1861 /// let status = Command::new("mkdir")
1862 /// .arg("projects")
1863 /// .status()
1864 /// .expect("failed to execute mkdir");
1865 ///
1866 /// if status.success() {
1867 /// println!("'projects/' directory created");
1868 /// } else {
1869 /// println!("failed to create 'projects/' directory: {status}");
1870 /// }
1871 /// ```
1872 #[must_use]
1873 #[stable(feature = "process", since = "1.0.0")]
1874 pub fn success(&self) -> bool {
1875 self.0.exit_ok().is_ok()
1876 }
1877
1878 /// Returns the exit code of the process, if any.
1879 ///
1880 /// In Unix terms the return value is the **exit status**: the value passed to `exit`, if the
1881 /// process finished by calling `exit`. Note that on Unix the exit status is truncated to 8
1882 /// bits, and that values that didn't come from a program's call to `exit` may be invented by the
1883 /// runtime system (often, for example, 255, 254, 127 or 126).
1884 ///
1885 /// On Unix, this will return `None` if the process was terminated by a signal.
1886 /// [`ExitStatusExt`](crate::os::unix::process::ExitStatusExt) is an
1887 /// extension trait for extracting any such signal, and other details, from the `ExitStatus`.
1888 ///
1889 /// # Examples
1890 ///
1891 /// ```no_run
1892 /// use std::process::Command;
1893 ///
1894 /// let status = Command::new("mkdir")
1895 /// .arg("projects")
1896 /// .status()
1897 /// .expect("failed to execute mkdir");
1898 ///
1899 /// match status.code() {
1900 /// Some(code) => println!("Exited with status code: {code}"),
1901 /// None => println!("Process terminated by signal")
1902 /// }
1903 /// ```
1904 #[must_use]
1905 #[stable(feature = "process", since = "1.0.0")]
1906 pub fn code(&self) -> Option<i32> {
1907 self.0.code()
1908 }
1909}
1910
1911impl AsInner<imp::ExitStatus> for ExitStatus {
1912 #[inline]
1913 fn as_inner(&self) -> &imp::ExitStatus {
1914 &self.0
1915 }
1916}
1917
1918impl FromInner<imp::ExitStatus> for ExitStatus {
1919 fn from_inner(s: imp::ExitStatus) -> ExitStatus {
1920 ExitStatus(s)
1921 }
1922}
1923
1924#[stable(feature = "process", since = "1.0.0")]
1925impl fmt::Display for ExitStatus {
1926 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1927 self.0.fmt(f)
1928 }
1929}
1930
1931/// Allows extension traits within `std`.
1932#[unstable(feature = "sealed", issue = "none")]
1933impl crate::sealed::Sealed for ExitStatusError {}
1934
1935/// Describes the result of a process after it has failed
1936///
1937/// Produced by the [`.exit_ok`](ExitStatus::exit_ok) method on [`ExitStatus`].
1938///
1939/// # Examples
1940///
1941/// ```
1942/// #![feature(exit_status_error)]
1943/// # if cfg!(all(unix, not(target_os = "android"), not(all(target_vendor = "apple", not(target_os = "macos"))))) {
1944/// use std::process::{Command, ExitStatusError};
1945///
1946/// fn run(cmd: &str) -> Result<(), ExitStatusError> {
1947/// Command::new(cmd).status().unwrap().exit_ok()?;
1948/// Ok(())
1949/// }
1950///
1951/// run("true").unwrap();
1952/// run("false").unwrap_err();
1953/// # } // cfg!(unix)
1954/// ```
1955#[derive(PartialEq, Eq, Clone, Copy, Debug)]
1956#[unstable(feature = "exit_status_error", issue = "84908")]
1957// The definition of imp::ExitStatusError should ideally be such that
1958// Result<(), imp::ExitStatusError> has an identical representation to imp::ExitStatus.
1959pub struct ExitStatusError(imp::ExitStatusError);
1960
1961#[unstable(feature = "exit_status_error", issue = "84908")]
1962impl ExitStatusError {
1963 /// Reports the exit code, if applicable, from an `ExitStatusError`.
1964 ///
1965 /// In Unix terms the return value is the **exit status**: the value passed to `exit`, if the
1966 /// process finished by calling `exit`. Note that on Unix the exit status is truncated to 8
1967 /// bits, and that values that didn't come from a program's call to `exit` may be invented by the
1968 /// runtime system (often, for example, 255, 254, 127 or 126).
1969 ///
1970 /// On Unix, this will return `None` if the process was terminated by a signal. If you want to
1971 /// handle such situations specially, consider using methods from
1972 /// [`ExitStatusExt`](crate::os::unix::process::ExitStatusExt).
1973 ///
1974 /// If the process finished by calling `exit` with a nonzero value, this will return
1975 /// that exit status.
1976 ///
1977 /// If the error was something else, it will return `None`.
1978 ///
1979 /// If the process exited successfully (ie, by calling `exit(0)`), there is no
1980 /// `ExitStatusError`. So the return value from `ExitStatusError::code()` is always nonzero.
1981 ///
1982 /// # Examples
1983 ///
1984 /// ```
1985 /// #![feature(exit_status_error)]
1986 /// # #[cfg(all(unix, not(target_os = "android"), not(all(target_vendor = "apple", not(target_os = "macos")))))] {
1987 /// use std::process::Command;
1988 ///
1989 /// let bad = Command::new("false").status().unwrap().exit_ok().unwrap_err();
1990 /// assert_eq!(bad.code(), Some(1));
1991 /// # } // #[cfg(unix)]
1992 /// ```
1993 #[must_use]
1994 pub fn code(&self) -> Option<i32> {
1995 self.code_nonzero().map(Into::into)
1996 }
1997
1998 /// Reports the exit code, if applicable, from an `ExitStatusError`, as a [`NonZero`].
1999 ///
2000 /// This is exactly like [`code()`](Self::code), except that it returns a <code>[NonZero]<[i32]></code>.
2001 ///
2002 /// Plain `code`, returning a plain integer, is provided because it is often more convenient.
2003 /// The returned value from `code()` is indeed also nonzero; use `code_nonzero()` when you want
2004 /// a type-level guarantee of nonzeroness.
2005 ///
2006 /// # Examples
2007 ///
2008 /// ```
2009 /// #![feature(exit_status_error)]
2010 ///
2011 /// # if cfg!(all(unix, not(target_os = "android"), not(all(target_vendor = "apple", not(target_os = "macos"))))) {
2012 /// use std::num::NonZero;
2013 /// use std::process::Command;
2014 ///
2015 /// let bad = Command::new("false").status().unwrap().exit_ok().unwrap_err();
2016 /// assert_eq!(bad.code_nonzero().unwrap(), NonZero::new(1).unwrap());
2017 /// # } // cfg!(unix)
2018 /// ```
2019 #[must_use]
2020 pub fn code_nonzero(&self) -> Option<NonZero<i32>> {
2021 self.0.code()
2022 }
2023
2024 /// Converts an `ExitStatusError` (back) to an `ExitStatus`.
2025 #[must_use]
2026 pub fn into_status(&self) -> ExitStatus {
2027 ExitStatus(self.0.into())
2028 }
2029}
2030
2031#[unstable(feature = "exit_status_error", issue = "84908")]
2032impl From<ExitStatusError> for ExitStatus {
2033 fn from(error: ExitStatusError) -> Self {
2034 Self(error.0.into())
2035 }
2036}
2037
2038#[unstable(feature = "exit_status_error", issue = "84908")]
2039impl fmt::Display for ExitStatusError {
2040 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2041 write!(f, "process exited unsuccessfully: {}", self.into_status())
2042 }
2043}
2044
2045#[unstable(feature = "exit_status_error", issue = "84908")]
2046impl crate::error::Error for ExitStatusError {}
2047
2048/// This type represents the status code the current process can return
2049/// to its parent under normal termination.
2050///
2051/// `ExitCode` is intended to be consumed only by the standard library (via
2052/// [`Termination::report()`]). For forwards compatibility with potentially
2053/// unusual targets, this type currently does not provide `Eq`, `Hash`, or
2054/// access to the raw value. This type does provide `PartialEq` for
2055/// comparison, but note that there may potentially be multiple failure
2056/// codes, some of which will _not_ compare equal to `ExitCode::FAILURE`.
2057/// The standard library provides the canonical `SUCCESS` and `FAILURE`
2058/// exit codes as well as `From<u8> for ExitCode` for constructing other
2059/// arbitrary exit codes.
2060///
2061/// # Portability
2062///
2063/// Numeric values used in this type don't have portable meanings, and
2064/// different platforms may mask different amounts of them.
2065///
2066/// For the platform's canonical successful and unsuccessful codes, see
2067/// the [`SUCCESS`] and [`FAILURE`] associated items.
2068///
2069/// [`SUCCESS`]: ExitCode::SUCCESS
2070/// [`FAILURE`]: ExitCode::FAILURE
2071///
2072/// # Differences from `ExitStatus`
2073///
2074/// `ExitCode` is intended for terminating the currently running process, via
2075/// the `Termination` trait, in contrast to [`ExitStatus`], which represents the
2076/// termination of a child process. These APIs are separate due to platform
2077/// compatibility differences and their expected usage; it is not generally
2078/// possible to exactly reproduce an `ExitStatus` from a child for the current
2079/// process after the fact.
2080///
2081/// # Examples
2082///
2083/// `ExitCode` can be returned from the `main` function of a crate, as it implements
2084/// [`Termination`]:
2085///
2086/// ```
2087/// use std::process::ExitCode;
2088/// # fn check_foo() -> bool { true }
2089///
2090/// fn main() -> ExitCode {
2091/// if !check_foo() {
2092/// return ExitCode::from(42);
2093/// }
2094///
2095/// ExitCode::SUCCESS
2096/// }
2097/// ```
2098#[derive(Clone, Copy, Debug, PartialEq)]
2099#[stable(feature = "process_exitcode", since = "1.61.0")]
2100pub struct ExitCode(imp::ExitCode);
2101
2102/// Allows extension traits within `std`.
2103#[unstable(feature = "sealed", issue = "none")]
2104impl crate::sealed::Sealed for ExitCode {}
2105
2106#[stable(feature = "process_exitcode", since = "1.61.0")]
2107impl ExitCode {
2108 /// The canonical `ExitCode` for successful termination on this platform.
2109 ///
2110 /// Note that a `()`-returning `main` implicitly results in a successful
2111 /// termination, so there's no need to return this from `main` unless
2112 /// you're also returning other possible codes.
2113 #[stable(feature = "process_exitcode", since = "1.61.0")]
2114 pub const SUCCESS: ExitCode = ExitCode(imp::ExitCode::SUCCESS);
2115
2116 /// The canonical `ExitCode` for unsuccessful termination on this platform.
2117 ///
2118 /// If you're only returning this and `SUCCESS` from `main`, consider
2119 /// instead returning `Err(_)` and `Ok(())` respectively, which will
2120 /// return the same codes (but will also `eprintln!` the error).
2121 #[stable(feature = "process_exitcode", since = "1.61.0")]
2122 pub const FAILURE: ExitCode = ExitCode(imp::ExitCode::FAILURE);
2123
2124 /// Exit the current process with the given `ExitCode`.
2125 ///
2126 /// Note that this has the same caveats as [`process::exit()`][exit], namely that this function
2127 /// terminates the process immediately, so no destructors on the current stack or any other
2128 /// thread's stack will be run. Also see those docs for some important notes on interop with C
2129 /// code. If a clean shutdown is needed, it is recommended to simply return this ExitCode from
2130 /// the `main` function, as demonstrated in the [type documentation](#examples).
2131 ///
2132 /// # Differences from `process::exit()`
2133 ///
2134 /// `process::exit()` accepts any `i32` value as the exit code for the process; however, there
2135 /// are platforms that only use a subset of that value (see [`process::exit` platform-specific
2136 /// behavior][exit#platform-specific-behavior]). `ExitCode` exists because of this; only
2137 /// `ExitCode`s that are supported by a majority of our platforms can be created, so those
2138 /// problems don't exist (as much) with this method.
2139 ///
2140 /// # Examples
2141 ///
2142 /// ```
2143 /// #![feature(exitcode_exit_method)]
2144 /// # use std::process::ExitCode;
2145 /// # use std::fmt;
2146 /// # enum UhOhError { GenericProblem, Specific, WithCode { exit_code: ExitCode, _x: () } }
2147 /// # impl fmt::Display for UhOhError {
2148 /// # fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result { unimplemented!() }
2149 /// # }
2150 /// // there's no way to gracefully recover from an UhOhError, so we just
2151 /// // print a message and exit
2152 /// fn handle_unrecoverable_error(err: UhOhError) -> ! {
2153 /// eprintln!("UH OH! {err}");
2154 /// let code = match err {
2155 /// UhOhError::GenericProblem => ExitCode::FAILURE,
2156 /// UhOhError::Specific => ExitCode::from(3),
2157 /// UhOhError::WithCode { exit_code, .. } => exit_code,
2158 /// };
2159 /// code.exit_process()
2160 /// }
2161 /// ```
2162 #[unstable(feature = "exitcode_exit_method", issue = "97100")]
2163 pub fn exit_process(self) -> ! {
2164 exit(self.to_i32())
2165 }
2166}
2167
2168impl ExitCode {
2169 // This is private/perma-unstable because ExitCode is opaque; we don't know that i32 will serve
2170 // all usecases, for example windows seems to use u32, unix uses the 8-15th bits of an i32, we
2171 // likely want to isolate users anything that could restrict the platform specific
2172 // representation of an ExitCode
2173 //
2174 // More info: https://internals.rust-lang.org/t/mini-pre-rfc-redesigning-process-exitstatus/5426
2175 /// Converts an `ExitCode` into an i32
2176 #[unstable(
2177 feature = "process_exitcode_internals",
2178 reason = "exposed only for libstd",
2179 issue = "none"
2180 )]
2181 #[inline]
2182 #[doc(hidden)]
2183 pub fn to_i32(self) -> i32 {
2184 self.0.as_i32()
2185 }
2186}
2187
2188/// The default value is [`ExitCode::SUCCESS`]
2189#[stable(feature = "process_exitcode_default", since = "1.75.0")]
2190impl Default for ExitCode {
2191 fn default() -> Self {
2192 ExitCode::SUCCESS
2193 }
2194}
2195
2196#[stable(feature = "process_exitcode", since = "1.61.0")]
2197impl From<u8> for ExitCode {
2198 /// Constructs an `ExitCode` from an arbitrary u8 value.
2199 fn from(code: u8) -> Self {
2200 ExitCode(imp::ExitCode::from(code))
2201 }
2202}
2203
2204impl AsInner<imp::ExitCode> for ExitCode {
2205 #[inline]
2206 fn as_inner(&self) -> &imp::ExitCode {
2207 &self.0
2208 }
2209}
2210
2211impl FromInner<imp::ExitCode> for ExitCode {
2212 fn from_inner(s: imp::ExitCode) -> ExitCode {
2213 ExitCode(s)
2214 }
2215}
2216
2217impl Child {
2218 /// Forces the child process to exit. If the child has already exited, `Ok(())`
2219 /// is returned.
2220 ///
2221 /// The mapping to [`ErrorKind`]s is not part of the compatibility contract of the function.
2222 ///
2223 /// This is equivalent to sending a SIGKILL on Unix platforms.
2224 ///
2225 /// # Examples
2226 ///
2227 /// ```no_run
2228 /// use std::process::Command;
2229 ///
2230 /// let mut command = Command::new("yes");
2231 /// if let Ok(mut child) = command.spawn() {
2232 /// child.kill().expect("command couldn't be killed");
2233 /// } else {
2234 /// println!("yes command didn't start");
2235 /// }
2236 /// ```
2237 ///
2238 /// [`ErrorKind`]: io::ErrorKind
2239 /// [`InvalidInput`]: io::ErrorKind::InvalidInput
2240 #[stable(feature = "process", since = "1.0.0")]
2241 #[cfg_attr(not(test), rustc_diagnostic_item = "child_kill")]
2242 pub fn kill(&mut self) -> io::Result<()> {
2243 self.handle.kill()
2244 }
2245
2246 /// Returns the OS-assigned process identifier associated with this child.
2247 ///
2248 /// # Examples
2249 ///
2250 /// ```no_run
2251 /// use std::process::Command;
2252 ///
2253 /// let mut command = Command::new("ls");
2254 /// if let Ok(child) = command.spawn() {
2255 /// println!("Child's ID is {}", child.id());
2256 /// } else {
2257 /// println!("ls command didn't start");
2258 /// }
2259 /// ```
2260 #[must_use]
2261 #[stable(feature = "process_id", since = "1.3.0")]
2262 #[cfg_attr(not(test), rustc_diagnostic_item = "child_id")]
2263 pub fn id(&self) -> u32 {
2264 self.handle.id()
2265 }
2266
2267 /// Waits for the child to exit completely, returning the status that it
2268 /// exited with. This function will continue to have the same return value
2269 /// after it has been called at least once.
2270 ///
2271 /// The stdin handle to the child process, if any, will be closed
2272 /// before waiting. This helps avoid deadlock: it ensures that the
2273 /// child does not block waiting for input from the parent, while
2274 /// the parent waits for the child to exit.
2275 ///
2276 /// # Examples
2277 ///
2278 /// ```no_run
2279 /// use std::process::Command;
2280 ///
2281 /// let mut command = Command::new("ls");
2282 /// if let Ok(mut child) = command.spawn() {
2283 /// child.wait().expect("command wasn't running");
2284 /// println!("Child has finished its execution!");
2285 /// } else {
2286 /// println!("ls command didn't start");
2287 /// }
2288 /// ```
2289 #[stable(feature = "process", since = "1.0.0")]
2290 pub fn wait(&mut self) -> io::Result<ExitStatus> {
2291 drop(self.stdin.take());
2292 self.handle.wait().map(ExitStatus)
2293 }
2294
2295 /// Attempts to collect the exit status of the child if it has already
2296 /// exited.
2297 ///
2298 /// This function will not block the calling thread and will only
2299 /// check to see if the child process has exited or not. If the child has
2300 /// exited then on Unix the process ID is reaped. This function is
2301 /// guaranteed to repeatedly return a successful exit status so long as the
2302 /// child has already exited.
2303 ///
2304 /// If the child has exited, then `Ok(Some(status))` is returned. If the
2305 /// exit status is not available at this time then `Ok(None)` is returned.
2306 /// If an error occurs, then that error is returned.
2307 ///
2308 /// Note that unlike `wait`, this function will not attempt to drop stdin.
2309 ///
2310 /// # Examples
2311 ///
2312 /// ```no_run
2313 /// use std::process::Command;
2314 ///
2315 /// let mut child = Command::new("ls").spawn()?;
2316 ///
2317 /// match child.try_wait() {
2318 /// Ok(Some(status)) => println!("exited with: {status}"),
2319 /// Ok(None) => {
2320 /// println!("status not ready yet, let's really wait");
2321 /// let res = child.wait();
2322 /// println!("result: {res:?}");
2323 /// }
2324 /// Err(e) => println!("error attempting to wait: {e}"),
2325 /// }
2326 /// # std::io::Result::Ok(())
2327 /// ```
2328 #[stable(feature = "process_try_wait", since = "1.18.0")]
2329 pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
2330 Ok(self.handle.try_wait()?.map(ExitStatus))
2331 }
2332
2333 /// Simultaneously waits for the child to exit and collect all remaining
2334 /// output on the stdout/stderr handles, returning an `Output`
2335 /// instance.
2336 ///
2337 /// The stdin handle to the child process, if any, will be closed
2338 /// before waiting. This helps avoid deadlock: it ensures that the
2339 /// child does not block waiting for input from the parent, while
2340 /// the parent waits for the child to exit.
2341 ///
2342 /// By default, stdin, stdout and stderr are inherited from the parent.
2343 /// In order to capture the output into this `Result<Output>` it is
2344 /// necessary to create new pipes between parent and child. Use
2345 /// `stdout(Stdio::piped())` or `stderr(Stdio::piped())`, respectively.
2346 ///
2347 /// # Examples
2348 ///
2349 /// ```should_panic
2350 /// use std::process::{Command, Stdio};
2351 ///
2352 /// let child = Command::new("/bin/cat")
2353 /// .arg("file.txt")
2354 /// .stdout(Stdio::piped())
2355 /// .spawn()
2356 /// .expect("failed to execute child");
2357 ///
2358 /// let output = child
2359 /// .wait_with_output()
2360 /// .expect("failed to wait on child");
2361 ///
2362 /// assert!(output.status.success());
2363 /// ```
2364 ///
2365 #[stable(feature = "process", since = "1.0.0")]
2366 pub fn wait_with_output(mut self) -> io::Result<Output> {
2367 drop(self.stdin.take());
2368
2369 let (mut stdout, mut stderr) = (Vec::new(), Vec::new());
2370 match (self.stdout.take(), self.stderr.take()) {
2371 (None, None) => {}
2372 (Some(mut out), None) => {
2373 let res = out.read_to_end(&mut stdout);
2374 res.unwrap();
2375 }
2376 (None, Some(mut err)) => {
2377 let res = err.read_to_end(&mut stderr);
2378 res.unwrap();
2379 }
2380 (Some(out), Some(err)) => {
2381 let res = imp::read_output(out.inner, &mut stdout, err.inner, &mut stderr);
2382 res.unwrap();
2383 }
2384 }
2385
2386 let status = self.wait()?;
2387 Ok(Output { status, stdout, stderr })
2388 }
2389}
2390
2391/// Terminates the current process with the specified exit code.
2392///
2393/// This function will never return and will immediately terminate the current
2394/// process. The exit code is passed through to the underlying OS and will be
2395/// available for consumption by another process.
2396///
2397/// Note that because this function never returns, and that it terminates the
2398/// process, no destructors on the current stack or any other thread's stack
2399/// will be run. If a clean shutdown is needed it is recommended to only call
2400/// this function at a known point where there are no more destructors left
2401/// to run; or, preferably, simply return a type implementing [`Termination`]
2402/// (such as [`ExitCode`] or `Result`) from the `main` function and avoid this
2403/// function altogether:
2404///
2405/// ```
2406/// # use std::io::Error as MyError;
2407/// fn main() -> Result<(), MyError> {
2408/// // ...
2409/// Ok(())
2410/// }
2411/// ```
2412///
2413/// In its current implementation, this function will execute exit handlers registered with `atexit`
2414/// as well as other platform-specific exit handlers (e.g. `fini` sections of ELF shared objects).
2415/// This means that Rust requires that all exit handlers are safe to execute at any time. In
2416/// particular, if an exit handler cleans up some state that might be concurrently accessed by other
2417/// threads, it is required that the exit handler performs suitable synchronization with those
2418/// threads. (The alternative to this requirement would be to not run exit handlers at all, which is
2419/// considered undesirable. Note that returning from `main` also calls `exit`, so making `exit` an
2420/// unsafe operation is not an option.)
2421///
2422/// ## Platform-specific behavior
2423///
2424/// **Unix**: On Unix-like platforms, it is unlikely that all 32 bits of `exit`
2425/// will be visible to a parent process inspecting the exit code. On most
2426/// Unix-like platforms, only the eight least-significant bits are considered.
2427///
2428/// For example, the exit code for this example will be `0` on Linux, but `256`
2429/// on Windows:
2430///
2431/// ```no_run
2432/// use std::process;
2433///
2434/// process::exit(0x0100);
2435/// ```
2436///
2437/// ### Safe interop with C code
2438///
2439/// On Unix, this function is currently implemented using the `exit` C function [`exit`][C-exit]. As
2440/// of C23, the C standard does not permit multiple threads to call `exit` concurrently. Rust
2441/// mitigates this with a lock, but if C code calls `exit`, that can still cause undefined behavior.
2442/// Note that returning from `main` is equivalent to calling `exit`.
2443///
2444/// Therefore, it is undefined behavior to have two concurrent threads perform the following
2445/// without synchronization:
2446/// - One thread calls Rust's `exit` function or returns from Rust's `main` function
2447/// - Another thread calls the C function `exit` or `quick_exit`, or returns from C's `main` function
2448///
2449/// Note that if a binary contains multiple copies of the Rust runtime (e.g., when combining
2450/// multiple `cdylib` or `staticlib`), they each have their own separate lock, so from the
2451/// perspective of code running in one of the Rust runtimes, the "outside" Rust code is basically C
2452/// code, and concurrent `exit` again causes undefined behavior.
2453///
2454/// Individual C implementations might provide more guarantees than the standard and permit concurrent
2455/// calls to `exit`; consult the documentation of your C implementation for details.
2456///
2457/// For some of the on-going discussion to make `exit` thread-safe in C, see:
2458/// - [Rust issue #126600](https://github.com/rust-lang/rust/issues/126600)
2459/// - [Austin Group Bugzilla (for POSIX)](https://austingroupbugs.net/view.php?id=1845)
2460/// - [GNU C library Bugzilla](https://sourceware.org/bugzilla/show_bug.cgi?id=31997)
2461///
2462/// [C-exit]: https://en.cppreference.com/w/c/program/exit
2463#[stable(feature = "rust1", since = "1.0.0")]
2464#[cfg_attr(not(test), rustc_diagnostic_item = "process_exit")]
2465pub fn exit(code: i32) -> ! {
2466 crate::rt::cleanup();
2467 crate::sys::os::exit(code)
2468}
2469
2470/// Terminates the process in an abnormal fashion.
2471///
2472/// The function will never return and will immediately terminate the current
2473/// process in a platform specific "abnormal" manner. As a consequence,
2474/// no destructors on the current stack or any other thread's stack
2475/// will be run, Rust IO buffers (eg, from `BufWriter`) will not be flushed,
2476/// and C stdio buffers will (on most platforms) not be flushed.
2477///
2478/// This is in contrast to the default behavior of [`panic!`] which unwinds
2479/// the current thread's stack and calls all destructors.
2480/// When `panic="abort"` is set, either as an argument to `rustc` or in a
2481/// crate's Cargo.toml, [`panic!`] and `abort` are similar. However,
2482/// [`panic!`] will still call the [panic hook] while `abort` will not.
2483///
2484/// If a clean shutdown is needed it is recommended to only call
2485/// this function at a known point where there are no more destructors left
2486/// to run.
2487///
2488/// The process's termination will be similar to that from the C `abort()`
2489/// function. On Unix, the process will terminate with signal `SIGABRT`, which
2490/// typically means that the shell prints "Aborted".
2491///
2492/// # Examples
2493///
2494/// ```no_run
2495/// use std::process;
2496///
2497/// fn main() {
2498/// println!("aborting");
2499///
2500/// process::abort();
2501///
2502/// // execution never gets here
2503/// }
2504/// ```
2505///
2506/// The `abort` function terminates the process, so the destructor will not
2507/// get run on the example below:
2508///
2509/// ```no_run
2510/// use std::process;
2511///
2512/// struct HasDrop;
2513///
2514/// impl Drop for HasDrop {
2515/// fn drop(&mut self) {
2516/// println!("This will never be printed!");
2517/// }
2518/// }
2519///
2520/// fn main() {
2521/// let _x = HasDrop;
2522/// process::abort();
2523/// // the destructor implemented for HasDrop will never get run
2524/// }
2525/// ```
2526///
2527/// [panic hook]: crate::panic::set_hook
2528#[stable(feature = "process_abort", since = "1.17.0")]
2529#[cold]
2530#[cfg_attr(not(test), rustc_diagnostic_item = "process_abort")]
2531#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
2532pub fn abort() -> ! {
2533 crate::sys::abort_internal();
2534}
2535
2536/// Returns the OS-assigned process identifier associated with this process.
2537///
2538/// # Examples
2539///
2540/// ```no_run
2541/// use std::process;
2542///
2543/// println!("My pid is {}", process::id());
2544/// ```
2545#[must_use]
2546#[stable(feature = "getpid", since = "1.26.0")]
2547pub fn id() -> u32 {
2548 crate::sys::os::getpid()
2549}
2550
2551/// A trait for implementing arbitrary return types in the `main` function.
2552///
2553/// The C-main function only supports returning integers.
2554/// So, every type implementing the `Termination` trait has to be converted
2555/// to an integer.
2556///
2557/// The default implementations are returning `libc::EXIT_SUCCESS` to indicate
2558/// a successful execution. In case of a failure, `libc::EXIT_FAILURE` is returned.
2559///
2560/// Because different runtimes have different specifications on the return value
2561/// of the `main` function, this trait is likely to be available only on
2562/// standard library's runtime for convenience. Other runtimes are not required
2563/// to provide similar functionality.
2564#[cfg_attr(not(any(test, doctest)), lang = "termination")]
2565#[stable(feature = "termination_trait_lib", since = "1.61.0")]
2566#[rustc_on_unimplemented(on(
2567 cause = "MainFunctionType",
2568 message = "`main` has invalid return type `{Self}`",
2569 label = "`main` can only return types that implement `{This}`"
2570))]
2571pub trait Termination {
2572 /// Is called to get the representation of the value as status code.
2573 /// This status code is returned to the operating system.
2574 #[stable(feature = "termination_trait_lib", since = "1.61.0")]
2575 fn report(self) -> ExitCode;
2576}
2577
2578#[stable(feature = "termination_trait_lib", since = "1.61.0")]
2579impl Termination for () {
2580 #[inline]
2581 fn report(self) -> ExitCode {
2582 ExitCode::SUCCESS
2583 }
2584}
2585
2586#[stable(feature = "termination_trait_lib", since = "1.61.0")]
2587impl Termination for ! {
2588 fn report(self) -> ExitCode {
2589 self
2590 }
2591}
2592
2593#[stable(feature = "termination_trait_lib", since = "1.61.0")]
2594impl Termination for Infallible {
2595 fn report(self) -> ExitCode {
2596 match self {}
2597 }
2598}
2599
2600#[stable(feature = "termination_trait_lib", since = "1.61.0")]
2601impl Termination for ExitCode {
2602 #[inline]
2603 fn report(self) -> ExitCode {
2604 self
2605 }
2606}
2607
2608#[stable(feature = "termination_trait_lib", since = "1.61.0")]
2609impl<T: Termination, E: fmt::Debug> Termination for Result<T, E> {
2610 fn report(self) -> ExitCode {
2611 match self {
2612 Ok(val) => val.report(),
2613 Err(err) => {
2614 io::attempt_print_to_stderr(args:format_args_nl!("Error: {err:?}"));
2615 ExitCode::FAILURE
2616 }
2617 }
2618 }
2619}
2620