1128 lines
34 KiB
Rust
1128 lines
34 KiB
Rust
//! Async interface for working with processes.
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//!
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//! This crate is an async version of [`std::process`].
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//!
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//! # Implementation
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//!
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//! A background thread named "async-process" is lazily created on first use, which waits for
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//! spawned child processes to exit and then calls the `wait()` syscall to clean up the "zombie"
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//! processes. This is unlike the `process` API in the standard library, where dropping a running
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//! `Child` leaks its resources.
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//!
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//! This crate uses [`async-io`] for async I/O on Unix-like systems and [`blocking`] for async I/O
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//! on Windows.
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//!
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//! [`async-io`]: https://docs.rs/async-io
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//! [`blocking`]: https://docs.rs/blocking
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//!
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//! # Examples
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//!
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//! Spawn a process and collect its output:
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//!
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//! ```no_run
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//! # futures_lite::future::block_on(async {
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//! use async_process::Command;
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//!
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//! let out = Command::new("echo").arg("hello").arg("world").output().await?;
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//! assert_eq!(out.stdout, b"hello world\n");
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//! # std::io::Result::Ok(()) });
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//! ```
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//!
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//! Read the output line-by-line as it gets produced:
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//!
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//! ```no_run
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//! # futures_lite::future::block_on(async {
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//! use async_process::{Command, Stdio};
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//! use futures_lite::{io::BufReader, prelude::*};
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//!
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//! let mut child = Command::new("find")
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//! .arg(".")
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//! .stdout(Stdio::piped())
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//! .spawn()?;
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//!
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//! let mut lines = BufReader::new(child.stdout.take().unwrap()).lines();
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//!
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//! while let Some(line) = lines.next().await {
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//! println!("{}", line?);
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//! }
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//! # std::io::Result::Ok(()) });
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//! ```
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#![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)]
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use std::ffi::OsStr;
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use std::fmt;
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use std::path::Path;
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use std::pin::Pin;
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use std::sync::{Arc, Mutex};
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use std::task::{Context, Poll};
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use std::thread;
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#[cfg(unix)]
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use async_io::Async;
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#[cfg(all(not(async_process_no_io_safety), unix))]
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use std::convert::{TryFrom, TryInto};
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#[cfg(all(not(async_process_no_io_safety), unix))]
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use std::os::unix::io::{AsFd, BorrowedFd, OwnedFd};
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#[cfg(unix)]
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use std::os::unix::io::{AsRawFd, RawFd};
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#[cfg(windows)]
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use blocking::Unblock;
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use async_lock::OnceCell;
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use event_listener::Event;
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use futures_lite::{future, io, prelude::*};
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#[doc(no_inline)]
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pub use std::process::{ExitStatus, Output, Stdio};
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#[cfg(unix)]
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pub mod unix;
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#[cfg(windows)]
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pub mod windows;
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mod sealed {
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pub trait Sealed {}
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}
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/// An event delivered every time the SIGCHLD signal occurs.
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static SIGCHLD: Event = Event::new();
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/// A guard that can kill child processes, or push them into the zombie list.
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struct ChildGuard {
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inner: Option<std::process::Child>,
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reap_on_drop: bool,
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kill_on_drop: bool,
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}
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impl ChildGuard {
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fn get_mut(&mut self) -> &mut std::process::Child {
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self.inner.as_mut().unwrap()
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}
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}
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/// A spawned child process.
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///
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/// The process can be in running or exited state. Use [`status()`][`Child::status()`] or
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/// [`output()`][`Child::output()`] to wait for it to exit.
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///
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/// If the [`Child`] is dropped, the process keeps running in the background.
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///
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/// # Examples
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///
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/// Spawn a process and wait for it to complete:
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///
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/// ```no_run
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/// # futures_lite::future::block_on(async {
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/// use async_process::Command;
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///
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/// Command::new("cp").arg("a.txt").arg("b.txt").status().await?;
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/// # std::io::Result::Ok(()) });
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/// ```
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pub struct Child {
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/// The handle for writing to the child's standard input (stdin), if it has been captured.
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pub stdin: Option<ChildStdin>,
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/// The handle for reading from the child's standard output (stdout), if it has been captured.
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pub stdout: Option<ChildStdout>,
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/// The handle for reading from the child's standard error (stderr), if it has been captured.
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pub stderr: Option<ChildStderr>,
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/// The inner child process handle.
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child: Arc<Mutex<ChildGuard>>,
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}
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impl Child {
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/// Wraps the inner child process handle and registers it in the global process list.
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///
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/// The "async-process" thread waits for processes in the global list and cleans up the
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/// resources when they exit.
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fn new(cmd: &mut Command) -> io::Result<Child> {
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let mut child = cmd.inner.spawn()?;
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// Convert sync I/O types into async I/O types.
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let stdin = child.stdin.take().map(wrap).transpose()?.map(ChildStdin);
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let stdout = child.stdout.take().map(wrap).transpose()?.map(ChildStdout);
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let stderr = child.stderr.take().map(wrap).transpose()?.map(ChildStderr);
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cfg_if::cfg_if! {
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if #[cfg(windows)] {
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use std::ffi::c_void;
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use std::os::windows::io::AsRawHandle;
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use std::sync::mpsc;
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use windows_sys::Win32::{
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System::{
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Threading::{RegisterWaitForSingleObject, WT_EXECUTEINWAITTHREAD, WT_EXECUTEONLYONCE},
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WindowsProgramming::INFINITE,
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},
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Foundation::{BOOLEAN, HANDLE},
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};
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// This channel is used to simulate SIGCHLD on Windows.
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fn callback_channel() -> (&'static mpsc::SyncSender<()>, &'static Mutex<mpsc::Receiver<()>>) {
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static CALLBACK: OnceCell<(mpsc::SyncSender<()>, Mutex<mpsc::Receiver<()>>)> =
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OnceCell::new();
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let (s, r) = CALLBACK.get_or_init_blocking(|| {
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let (s, r) = mpsc::sync_channel(1);
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(s, Mutex::new(r))
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});
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(s, r)
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}
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// Called when a child exits.
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unsafe extern "system" fn callback(_: *mut c_void, _: BOOLEAN) {
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callback_channel().0.try_send(()).ok();
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}
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// Register this child process to invoke `callback` on exit.
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let mut wait_object = 0;
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let ret = unsafe {
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RegisterWaitForSingleObject(
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&mut wait_object,
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child.as_raw_handle() as HANDLE,
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Some(callback),
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std::ptr::null_mut(),
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INFINITE,
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WT_EXECUTEINWAITTHREAD | WT_EXECUTEONLYONCE,
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)
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};
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if ret == 0 {
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return Err(io::Error::last_os_error());
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}
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// Waits for the next SIGCHLD signal.
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fn wait_sigchld() {
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callback_channel().1.lock().unwrap().recv().ok();
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}
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// Wraps a sync I/O type into an async I/O type.
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fn wrap<T>(io: T) -> io::Result<Unblock<T>> {
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Ok(Unblock::new(io))
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}
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} else if #[cfg(unix)] {
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static SIGNALS: OnceCell<Mutex<signal_hook::iterator::Signals>> = OnceCell::new();
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// Make sure the signal handler is registered before interacting with the process.
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SIGNALS.get_or_init_blocking(|| Mutex::new(
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signal_hook::iterator::Signals::new(&[signal_hook::consts::SIGCHLD])
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.expect("cannot set signal handler for SIGCHLD"),
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));
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// Waits for the next SIGCHLD signal.
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fn wait_sigchld() {
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SIGNALS.get().expect("Signals not registered").lock().unwrap().forever().next();
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}
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// Wraps a sync I/O type into an async I/O type.
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fn wrap<T: std::os::unix::io::AsRawFd>(io: T) -> io::Result<Async<T>> {
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Async::new(io)
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}
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}
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}
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static ZOMBIES: OnceCell<Mutex<Vec<std::process::Child>>> = OnceCell::new();
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// Make sure the thread is started.
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ZOMBIES.get_or_init_blocking(|| {
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// Start a thread that handles SIGCHLD and notifies tasks when child processes exit.
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thread::Builder::new()
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.name("async-process".to_string())
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.spawn(move || {
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loop {
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// Wait for the next SIGCHLD signal.
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wait_sigchld();
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// Notify all listeners waiting on the SIGCHLD event.
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SIGCHLD.notify(std::usize::MAX);
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// Reap zombie processes.
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let mut zombies = ZOMBIES.get().unwrap().lock().unwrap();
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let mut i = 0;
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while i < zombies.len() {
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if let Ok(None) = zombies[i].try_wait() {
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i += 1;
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} else {
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zombies.swap_remove(i);
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}
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}
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}
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})
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.expect("cannot spawn async-process thread");
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Mutex::new(Vec::new())
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});
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// When the last reference to the child process is dropped, push it into the zombie list.
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impl Drop for ChildGuard {
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fn drop(&mut self) {
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if self.kill_on_drop {
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self.get_mut().kill().ok();
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}
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if self.reap_on_drop {
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let mut zombies = ZOMBIES.get().unwrap().lock().unwrap();
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if let Ok(None) = self.get_mut().try_wait() {
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zombies.push(self.inner.take().unwrap());
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}
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}
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}
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}
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Ok(Child {
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stdin,
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stdout,
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stderr,
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child: Arc::new(Mutex::new(ChildGuard {
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inner: Some(child),
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reap_on_drop: cmd.reap_on_drop,
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kill_on_drop: cmd.kill_on_drop,
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})),
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})
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}
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/// Returns the OS-assigned process identifier associated with this child.
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///
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/// # Examples
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///
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/// ```no_run
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/// # futures_lite::future::block_on(async {
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/// use async_process::Command;
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///
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/// let mut child = Command::new("ls").spawn()?;
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/// println!("id: {}", child.id());
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/// # std::io::Result::Ok(()) });
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/// ```
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pub fn id(&self) -> u32 {
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self.child.lock().unwrap().get_mut().id()
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}
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/// Forces the child process to exit.
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///
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/// If the child has already exited, an [`InvalidInput`] error is returned.
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///
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/// This is equivalent to sending a SIGKILL on Unix platforms.
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///
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/// [`InvalidInput`]: `std::io::ErrorKind::InvalidInput`
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///
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/// # Examples
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///
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/// ```no_run
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/// # futures_lite::future::block_on(async {
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/// use async_process::Command;
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///
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/// let mut child = Command::new("yes").spawn()?;
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/// child.kill()?;
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/// println!("exit status: {}", child.status().await?);
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/// # std::io::Result::Ok(()) });
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/// ```
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pub fn kill(&mut self) -> io::Result<()> {
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self.child.lock().unwrap().get_mut().kill()
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}
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/// Returns the exit status if the process has exited.
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///
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/// Unlike [`status()`][`Child::status()`], this method will not drop the stdin handle.
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///
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/// # Examples
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///
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/// ```no_run
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/// # futures_lite::future::block_on(async {
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/// use async_process::Command;
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///
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/// let mut child = Command::new("ls").spawn()?;
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///
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/// match child.try_status()? {
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/// None => println!("still running"),
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/// Some(status) => println!("exited with: {}", status),
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/// }
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/// # std::io::Result::Ok(()) });
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/// ```
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pub fn try_status(&mut self) -> io::Result<Option<ExitStatus>> {
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self.child.lock().unwrap().get_mut().try_wait()
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}
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/// Drops the stdin handle and waits for the process to exit.
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///
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/// Closing the stdin of the process helps avoid deadlocks. It ensures that the process does
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/// not block waiting for input from the parent process while the parent waits for the child to
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/// exit.
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///
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/// # Examples
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///
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/// ```no_run
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/// # futures_lite::future::block_on(async {
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/// use async_process::{Command, Stdio};
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///
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/// let mut child = Command::new("cp")
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/// .arg("a.txt")
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/// .arg("b.txt")
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/// .spawn()?;
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///
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/// println!("exit status: {}", child.status().await?);
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/// # std::io::Result::Ok(()) });
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/// ```
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pub fn status(&mut self) -> impl Future<Output = io::Result<ExitStatus>> {
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self.stdin.take();
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let child = self.child.clone();
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async move {
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let mut listener = None;
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loop {
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if let Some(status) = child.lock().unwrap().get_mut().try_wait()? {
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return Ok(status);
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}
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match listener.take() {
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None => listener = Some(SIGCHLD.listen()),
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Some(listener) => listener.await,
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}
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}
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}
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}
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/// Drops the stdin handle and collects the output of the process.
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///
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/// Closing the stdin of the process helps avoid deadlocks. It ensures that the process does
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/// not block waiting for input from the parent process while the parent waits for the child to
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/// exit.
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///
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/// In order to capture the output of the process, [`Command::stdout()`] and
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/// [`Command::stderr()`] must be configured with [`Stdio::piped()`].
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///
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/// # Examples
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///
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/// ```no_run
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/// # futures_lite::future::block_on(async {
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/// use async_process::{Command, Stdio};
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///
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/// let child = Command::new("ls")
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/// .stdout(Stdio::piped())
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/// .stderr(Stdio::piped())
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/// .spawn()?;
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///
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/// let out = child.output().await?;
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/// # std::io::Result::Ok(()) });
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/// ```
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pub fn output(mut self) -> impl Future<Output = io::Result<Output>> {
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// A future that waits for the exit status.
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let status = self.status();
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// A future that collects stdout.
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let stdout = self.stdout.take();
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let stdout = async move {
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let mut v = Vec::new();
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if let Some(mut s) = stdout {
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s.read_to_end(&mut v).await?;
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}
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io::Result::Ok(v)
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};
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|
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// A future that collects stderr.
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let stderr = self.stderr.take();
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let stderr = async move {
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let mut v = Vec::new();
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if let Some(mut s) = stderr {
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s.read_to_end(&mut v).await?;
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}
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io::Result::Ok(v)
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};
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async move {
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let (stdout, stderr) = future::try_zip(stdout, stderr).await?;
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let status = status.await?;
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Ok(Output {
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status,
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stdout,
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stderr,
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})
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}
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}
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}
|
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|
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impl fmt::Debug for Child {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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f.debug_struct("Child")
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.field("stdin", &self.stdin)
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.field("stdout", &self.stdout)
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.field("stderr", &self.stderr)
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.finish()
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}
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}
|
|
|
|
/// A handle to a child process's standard input (stdin).
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///
|
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/// When a [`ChildStdin`] is dropped, the underlying handle gets clossed. If the child process was
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/// previously blocked on input, it becomes unblocked after dropping.
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#[derive(Debug)]
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pub struct ChildStdin(
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#[cfg(windows)] Unblock<std::process::ChildStdin>,
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#[cfg(unix)] Async<std::process::ChildStdin>,
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);
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|
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impl ChildStdin {
|
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/// Convert async_process::ChildStdin into std::process::Stdio.
|
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///
|
|
/// You can use it to associate to the next process.
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|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
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|
/// use std::process::Stdio;
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|
///
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|
/// let mut ls_child = Command::new("ls").stdin(Stdio::piped()).spawn()?;
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/// let stdio:Stdio = ls_child.stdin.take().unwrap().into_stdio().await?;
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///
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/// let mut echo_child = Command::new("echo").arg("./").stdout(stdio).spawn()?;
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///
|
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/// # std::io::Result::Ok(()) });
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/// ```
|
|
pub async fn into_stdio(self) -> io::Result<std::process::Stdio> {
|
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cfg_if::cfg_if! {
|
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if #[cfg(windows)] {
|
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Ok(self.0.into_inner().await.into())
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|
} else if #[cfg(unix)] {
|
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let child_stdin = self.0.into_inner()?;
|
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blocking_fd(rustix::fd::AsFd::as_fd(&child_stdin))?;
|
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Ok(child_stdin.into())
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|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl io::AsyncWrite for ChildStdin {
|
|
fn poll_write(
|
|
mut self: Pin<&mut Self>,
|
|
cx: &mut Context<'_>,
|
|
buf: &[u8],
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|
) -> Poll<io::Result<usize>> {
|
|
Pin::new(&mut self.0).poll_write(cx, buf)
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|
}
|
|
|
|
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
|
|
Pin::new(&mut self.0).poll_flush(cx)
|
|
}
|
|
|
|
fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
|
|
Pin::new(&mut self.0).poll_close(cx)
|
|
}
|
|
}
|
|
|
|
#[cfg(unix)]
|
|
impl AsRawFd for ChildStdin {
|
|
fn as_raw_fd(&self) -> RawFd {
|
|
self.0.as_raw_fd()
|
|
}
|
|
}
|
|
|
|
#[cfg(all(not(async_process_no_io_safety), unix))]
|
|
impl AsFd for ChildStdin {
|
|
fn as_fd(&self) -> BorrowedFd<'_> {
|
|
self.0.as_fd()
|
|
}
|
|
}
|
|
|
|
#[cfg(all(not(async_process_no_io_safety), unix))]
|
|
impl TryFrom<ChildStdin> for OwnedFd {
|
|
type Error = io::Error;
|
|
|
|
fn try_from(value: ChildStdin) -> Result<Self, Self::Error> {
|
|
value.0.try_into()
|
|
}
|
|
}
|
|
|
|
// TODO(notgull): Add mirroring AsRawHandle impls for all of the child handles
|
|
//
|
|
// at the moment this is pretty hard to do because of how they're wrapped in
|
|
// Unblock, meaning that we can't always access the underlying handle. async-fs
|
|
// gets around this by putting the handle in an Arc, but there's still some decision
|
|
// to be made about how to handle this (no pun intended)
|
|
|
|
/// A handle to a child process's standard output (stdout).
|
|
///
|
|
/// When a [`ChildStdout`] is dropped, the underlying handle gets closed.
|
|
#[derive(Debug)]
|
|
pub struct ChildStdout(
|
|
#[cfg(windows)] Unblock<std::process::ChildStdout>,
|
|
#[cfg(unix)] Async<std::process::ChildStdout>,
|
|
);
|
|
|
|
impl ChildStdout {
|
|
/// Convert async_process::ChildStdout into std::process::Stdio.
|
|
///
|
|
/// You can use it to associate to the next process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
|
|
/// use std::process::Stdio;
|
|
/// use std::io::Read;
|
|
/// use futures_lite::AsyncReadExt;
|
|
///
|
|
/// let mut ls_child = Command::new("ls").stdout(Stdio::piped()).spawn()?;
|
|
/// let stdio:Stdio = ls_child.stdout.take().unwrap().into_stdio().await?;
|
|
///
|
|
/// let mut echo_child = Command::new("echo").stdin(stdio).stdout(Stdio::piped()).spawn()?;
|
|
/// let mut buf = vec![];
|
|
/// echo_child.stdout.take().unwrap().read(&mut buf).await;
|
|
/// # std::io::Result::Ok(()) });
|
|
/// ```
|
|
pub async fn into_stdio(self) -> io::Result<std::process::Stdio> {
|
|
cfg_if::cfg_if! {
|
|
if #[cfg(windows)] {
|
|
Ok(self.0.into_inner().await.into())
|
|
} else if #[cfg(unix)] {
|
|
let child_stdout = self.0.into_inner()?;
|
|
blocking_fd(rustix::fd::AsFd::as_fd(&child_stdout))?;
|
|
Ok(child_stdout.into())
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl io::AsyncRead for ChildStdout {
|
|
fn poll_read(
|
|
mut self: Pin<&mut Self>,
|
|
cx: &mut Context<'_>,
|
|
buf: &mut [u8],
|
|
) -> Poll<io::Result<usize>> {
|
|
Pin::new(&mut self.0).poll_read(cx, buf)
|
|
}
|
|
}
|
|
|
|
#[cfg(unix)]
|
|
impl AsRawFd for ChildStdout {
|
|
fn as_raw_fd(&self) -> RawFd {
|
|
self.0.as_raw_fd()
|
|
}
|
|
}
|
|
|
|
#[cfg(all(not(async_process_no_io_safety), unix))]
|
|
impl AsFd for ChildStdout {
|
|
fn as_fd(&self) -> BorrowedFd<'_> {
|
|
self.0.as_fd()
|
|
}
|
|
}
|
|
|
|
#[cfg(all(not(async_process_no_io_safety), unix))]
|
|
impl TryFrom<ChildStdout> for OwnedFd {
|
|
type Error = io::Error;
|
|
|
|
fn try_from(value: ChildStdout) -> Result<Self, Self::Error> {
|
|
value.0.try_into()
|
|
}
|
|
}
|
|
|
|
/// A handle to a child process's standard error (stderr).
|
|
///
|
|
/// When a [`ChildStderr`] is dropped, the underlying handle gets closed.
|
|
#[derive(Debug)]
|
|
pub struct ChildStderr(
|
|
#[cfg(windows)] Unblock<std::process::ChildStderr>,
|
|
#[cfg(unix)] Async<std::process::ChildStderr>,
|
|
);
|
|
|
|
impl ChildStderr {
|
|
/// Convert async_process::ChildStderr into std::process::Stdio.
|
|
///
|
|
/// You can use it to associate to the next process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
|
|
/// use std::process::Stdio;
|
|
///
|
|
/// let mut ls_child = Command::new("ls").arg("x").stderr(Stdio::piped()).spawn()?;
|
|
/// let stdio:Stdio = ls_child.stderr.take().unwrap().into_stdio().await?;
|
|
///
|
|
/// let mut echo_child = Command::new("echo").stdin(stdio).spawn()?;
|
|
/// # std::io::Result::Ok(()) });
|
|
/// ```
|
|
pub async fn into_stdio(self) -> io::Result<std::process::Stdio> {
|
|
cfg_if::cfg_if! {
|
|
if #[cfg(windows)] {
|
|
Ok(self.0.into_inner().await.into())
|
|
} else if #[cfg(unix)] {
|
|
let child_stderr = self.0.into_inner()?;
|
|
blocking_fd(rustix::fd::AsFd::as_fd(&child_stderr))?;
|
|
Ok(child_stderr.into())
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl io::AsyncRead for ChildStderr {
|
|
fn poll_read(
|
|
mut self: Pin<&mut Self>,
|
|
cx: &mut Context<'_>,
|
|
buf: &mut [u8],
|
|
) -> Poll<io::Result<usize>> {
|
|
Pin::new(&mut self.0).poll_read(cx, buf)
|
|
}
|
|
}
|
|
|
|
#[cfg(unix)]
|
|
impl AsRawFd for ChildStderr {
|
|
fn as_raw_fd(&self) -> RawFd {
|
|
self.0.as_raw_fd()
|
|
}
|
|
}
|
|
|
|
#[cfg(all(not(async_process_no_io_safety), unix))]
|
|
impl AsFd for ChildStderr {
|
|
fn as_fd(&self) -> BorrowedFd<'_> {
|
|
self.0.as_fd()
|
|
}
|
|
}
|
|
|
|
#[cfg(all(not(async_process_no_io_safety), unix))]
|
|
impl TryFrom<ChildStderr> for OwnedFd {
|
|
type Error = io::Error;
|
|
|
|
fn try_from(value: ChildStderr) -> Result<Self, Self::Error> {
|
|
value.0.try_into()
|
|
}
|
|
}
|
|
|
|
/// A builder for spawning processes.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
|
|
///
|
|
/// let output = if cfg!(target_os = "windows") {
|
|
/// Command::new("cmd").args(&["/C", "echo hello"]).output().await?
|
|
/// } else {
|
|
/// Command::new("sh").arg("-c").arg("echo hello").output().await?
|
|
/// };
|
|
/// # std::io::Result::Ok(()) });
|
|
/// ```
|
|
pub struct Command {
|
|
inner: std::process::Command,
|
|
stdin: bool,
|
|
stdout: bool,
|
|
stderr: bool,
|
|
reap_on_drop: bool,
|
|
kill_on_drop: bool,
|
|
}
|
|
|
|
impl Command {
|
|
/// Constructs a new [`Command`] for launching `program`.
|
|
///
|
|
/// The initial configuration (the working directory and environment variables) is inherited
|
|
/// from the current process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// ```
|
|
pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
|
|
Self::from(std::process::Command::new(program))
|
|
}
|
|
|
|
/// Adds a single argument to pass to the program.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("echo");
|
|
/// cmd.arg("hello");
|
|
/// cmd.arg("world");
|
|
/// ```
|
|
pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Command {
|
|
self.inner.arg(arg);
|
|
self
|
|
}
|
|
|
|
/// Adds multiple arguments to pass to the program.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("echo");
|
|
/// cmd.args(&["hello", "world"]);
|
|
/// ```
|
|
pub fn args<I, S>(&mut self, args: I) -> &mut Command
|
|
where
|
|
I: IntoIterator<Item = S>,
|
|
S: AsRef<OsStr>,
|
|
{
|
|
self.inner.args(args);
|
|
self
|
|
}
|
|
|
|
/// Configures an environment variable for the new process.
|
|
///
|
|
/// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
|
|
/// and case-sensitive on all other platforms.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.env("PATH", "/bin");
|
|
/// ```
|
|
pub fn env<K, V>(&mut self, key: K, val: V) -> &mut Command
|
|
where
|
|
K: AsRef<OsStr>,
|
|
V: AsRef<OsStr>,
|
|
{
|
|
self.inner.env(key, val);
|
|
self
|
|
}
|
|
|
|
/// Configures multiple environment variables for the new process.
|
|
///
|
|
/// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
|
|
/// and case-sensitive on all other platforms.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.envs(vec![("PATH", "/bin"), ("TERM", "xterm-256color")]);
|
|
/// ```
|
|
pub fn envs<I, K, V>(&mut self, vars: I) -> &mut Command
|
|
where
|
|
I: IntoIterator<Item = (K, V)>,
|
|
K: AsRef<OsStr>,
|
|
V: AsRef<OsStr>,
|
|
{
|
|
self.inner.envs(vars);
|
|
self
|
|
}
|
|
|
|
/// Removes an environment variable mapping.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.env_remove("PATH");
|
|
/// ```
|
|
pub fn env_remove<K: AsRef<OsStr>>(&mut self, key: K) -> &mut Command {
|
|
self.inner.env_remove(key);
|
|
self
|
|
}
|
|
|
|
/// Removes all environment variable mappings.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.env_clear();
|
|
/// ```
|
|
pub fn env_clear(&mut self) -> &mut Command {
|
|
self.inner.env_clear();
|
|
self
|
|
}
|
|
|
|
/// Configures the working directory for the new process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::Command;
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.current_dir("/");
|
|
/// ```
|
|
pub fn current_dir<P: AsRef<Path>>(&mut self, dir: P) -> &mut Command {
|
|
self.inner.current_dir(dir);
|
|
self
|
|
}
|
|
|
|
/// Configures the standard input (stdin) for the new process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::{Command, Stdio};
|
|
///
|
|
/// let mut cmd = Command::new("cat");
|
|
/// cmd.stdin(Stdio::null());
|
|
/// ```
|
|
pub fn stdin<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Command {
|
|
self.stdin = true;
|
|
self.inner.stdin(cfg);
|
|
self
|
|
}
|
|
|
|
/// Configures the standard output (stdout) for the new process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::{Command, Stdio};
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.stdout(Stdio::piped());
|
|
/// ```
|
|
pub fn stdout<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Command {
|
|
self.stdout = true;
|
|
self.inner.stdout(cfg);
|
|
self
|
|
}
|
|
|
|
/// Configures the standard error (stderr) for the new process.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::{Command, Stdio};
|
|
///
|
|
/// let mut cmd = Command::new("ls");
|
|
/// cmd.stderr(Stdio::piped());
|
|
/// ```
|
|
pub fn stderr<T: Into<Stdio>>(&mut self, cfg: T) -> &mut Command {
|
|
self.stderr = true;
|
|
self.inner.stderr(cfg);
|
|
self
|
|
}
|
|
|
|
/// Configures whether to reap the zombie process when [`Child`] is dropped.
|
|
///
|
|
/// When the process finishes, it becomes a "zombie" and some resources associated with it
|
|
/// remain until [`Child::try_status()`], [`Child::status()`], or [`Child::output()`] collects
|
|
/// its exit code.
|
|
///
|
|
/// If its exit code is never collected, the resources may leak forever. This crate has a
|
|
/// background thread named "async-process" that collects such "zombie" processes and then
|
|
/// "reaps" them, thus preventing the resource leaks.
|
|
///
|
|
/// The default value of this option is `true`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::{Command, Stdio};
|
|
///
|
|
/// let mut cmd = Command::new("cat");
|
|
/// cmd.reap_on_drop(false);
|
|
/// ```
|
|
pub fn reap_on_drop(&mut self, reap_on_drop: bool) -> &mut Command {
|
|
self.reap_on_drop = reap_on_drop;
|
|
self
|
|
}
|
|
|
|
/// Configures whether to kill the process when [`Child`] is dropped.
|
|
///
|
|
/// The default value of this option is `false`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use async_process::{Command, Stdio};
|
|
///
|
|
/// let mut cmd = Command::new("cat");
|
|
/// cmd.kill_on_drop(true);
|
|
/// ```
|
|
pub fn kill_on_drop(&mut self, kill_on_drop: bool) -> &mut Command {
|
|
self.kill_on_drop = kill_on_drop;
|
|
self
|
|
}
|
|
|
|
/// Executes the command and returns the [`Child`] handle to it.
|
|
///
|
|
/// If not configured, stdin, stdout and stderr will be set to [`Stdio::inherit()`].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
|
|
///
|
|
/// let child = Command::new("ls").spawn()?;
|
|
/// # std::io::Result::Ok(()) });
|
|
/// ```
|
|
pub fn spawn(&mut self) -> io::Result<Child> {
|
|
if !self.stdin {
|
|
self.inner.stdin(Stdio::inherit());
|
|
}
|
|
if !self.stdout {
|
|
self.inner.stdout(Stdio::inherit());
|
|
}
|
|
if !self.stderr {
|
|
self.inner.stderr(Stdio::inherit());
|
|
}
|
|
|
|
Child::new(self)
|
|
}
|
|
|
|
/// Executes the command, waits for it to exit, and returns the exit status.
|
|
///
|
|
/// If not configured, stdin, stdout and stderr will be set to [`Stdio::inherit()`].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
|
|
///
|
|
/// let status = Command::new("cp")
|
|
/// .arg("a.txt")
|
|
/// .arg("b.txt")
|
|
/// .status()
|
|
/// .await?;
|
|
/// # std::io::Result::Ok(()) });
|
|
/// ```
|
|
pub fn status(&mut self) -> impl Future<Output = io::Result<ExitStatus>> {
|
|
let child = self.spawn();
|
|
async { child?.status().await }
|
|
}
|
|
|
|
/// Executes the command and collects its output.
|
|
///
|
|
/// If not configured, stdin will be set to [`Stdio::null()`], and stdout and stderr will be
|
|
/// set to [`Stdio::piped()`].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```no_run
|
|
/// # futures_lite::future::block_on(async {
|
|
/// use async_process::Command;
|
|
///
|
|
/// let output = Command::new("cat")
|
|
/// .arg("a.txt")
|
|
/// .output()
|
|
/// .await?;
|
|
/// # std::io::Result::Ok(()) });
|
|
/// ```
|
|
pub fn output(&mut self) -> impl Future<Output = io::Result<Output>> {
|
|
if !self.stdin {
|
|
self.inner.stdin(Stdio::null());
|
|
}
|
|
if !self.stdout {
|
|
self.inner.stdout(Stdio::piped());
|
|
}
|
|
if !self.stderr {
|
|
self.inner.stderr(Stdio::piped());
|
|
}
|
|
|
|
let child = Child::new(self);
|
|
async { child?.output().await }
|
|
}
|
|
}
|
|
|
|
impl From<std::process::Command> for Command {
|
|
fn from(inner: std::process::Command) -> Self {
|
|
Self {
|
|
inner,
|
|
stdin: false,
|
|
stdout: false,
|
|
stderr: false,
|
|
reap_on_drop: true,
|
|
kill_on_drop: false,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for Command {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
if f.alternate() {
|
|
f.debug_struct("Command")
|
|
.field("inner", &self.inner)
|
|
.field("stdin", &self.stdin)
|
|
.field("stdout", &self.stdout)
|
|
.field("stderr", &self.stderr)
|
|
.field("reap_on_drop", &self.reap_on_drop)
|
|
.field("kill_on_drop", &self.kill_on_drop)
|
|
.finish()
|
|
} else {
|
|
// Stdlib outputs command-line in Debug for Command. This does the
|
|
// same, if not in "alternate" (long pretty-printed) mode.
|
|
// This is useful for logs, for example.
|
|
fmt::Debug::fmt(&self.inner, f)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Moves `Fd` out of non-blocking mode.
|
|
#[cfg(unix)]
|
|
fn blocking_fd(fd: rustix::fd::BorrowedFd<'_>) -> io::Result<()> {
|
|
cfg_if::cfg_if! {
|
|
// ioctl(FIONBIO) sets the flag atomically, but we use this only on Linux
|
|
// for now, as with the standard library, because it seems to behave
|
|
// differently depending on the platform.
|
|
// https://github.com/rust-lang/rust/commit/efeb42be2837842d1beb47b51bb693c7474aba3d
|
|
// https://github.com/libuv/libuv/blob/e9d91fccfc3e5ff772d5da90e1c4a24061198ca0/src/unix/poll.c#L78-L80
|
|
// https://github.com/tokio-rs/mio/commit/0db49f6d5caf54b12176821363d154384357e70a
|
|
if #[cfg(target_os = "linux")] {
|
|
rustix::io::ioctl_fionbio(fd, false)?;
|
|
} else {
|
|
let previous = rustix::fs::fcntl_getfl(fd)?;
|
|
let new = previous & !rustix::fs::OFlags::NONBLOCK;
|
|
if new != previous {
|
|
rustix::fs::fcntl_setfl(fd, new)?;
|
|
}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
#[cfg(unix)]
|
|
mod test {
|
|
|
|
#[test]
|
|
fn test_into_inner() {
|
|
futures_lite::future::block_on(async {
|
|
use crate::Command;
|
|
|
|
use std::io::Result;
|
|
use std::process::Stdio;
|
|
use std::str::from_utf8;
|
|
|
|
use futures_lite::AsyncReadExt;
|
|
|
|
let mut ls_child = Command::new("cat")
|
|
.arg("Cargo.toml")
|
|
.stdout(Stdio::piped())
|
|
.spawn()?;
|
|
|
|
let stdio: Stdio = ls_child.stdout.take().unwrap().into_stdio().await?;
|
|
|
|
let mut echo_child = Command::new("grep")
|
|
.arg("async")
|
|
.stdin(stdio)
|
|
.stdout(Stdio::piped())
|
|
.spawn()?;
|
|
|
|
let mut buf = vec![];
|
|
let mut stdout = echo_child.stdout.take().unwrap();
|
|
|
|
stdout.read_to_end(&mut buf).await?;
|
|
dbg!(from_utf8(&buf).unwrap_or(""));
|
|
|
|
Result::Ok(())
|
|
})
|
|
.unwrap();
|
|
}
|
|
}
|