pub struct Child {
pub stdin: Option<ChildStdin>,
pub stdout: Option<ChildStdout>,
pub stderr: Option<ChildStderr>,
/* private fields */
}
Expand description
A spawned child process.
The process can be in running or exited state. Use status()
or
output()
to wait for it to exit.
If the Child
is dropped, the process keeps running in the background.
Examples
Spawn a process and wait for it to complete:
use async_process::Command;
Command::new("cp").arg("a.txt").arg("b.txt").status().await?;
Fields
stdin: Option<ChildStdin>
The handle for writing to the child’s standard input (stdin), if it has been captured.
stdout: Option<ChildStdout>
The handle for reading from the child’s standard output (stdout), if it has been captured.
stderr: Option<ChildStderr>
The handle for reading from the child’s standard error (stderr), if it has been captured.
Implementations
sourceimpl Child
impl Child
sourcepub fn id(&self) -> u32
pub fn id(&self) -> u32
Returns the OS-assigned process identifier associated with this child.
Examples
use async_process::Command;
let mut child = Command::new("ls").spawn()?;
println!("id: {}", child.id());
sourcepub fn kill(&mut self) -> Result<(), Error>
pub fn kill(&mut self) -> Result<(), Error>
Forces the child process to exit.
If the child has already exited, an InvalidInput
error is returned.
This is equivalent to sending a SIGKILL on Unix platforms.
Examples
use async_process::Command;
let mut child = Command::new("yes").spawn()?;
child.kill()?;
println!("exit status: {}", child.status().await?);
sourcepub fn try_status(&mut self) -> Result<Option<ExitStatus>, Error>
pub fn try_status(&mut self) -> Result<Option<ExitStatus>, Error>
Returns the exit status if the process has exited.
Unlike status()
, this method will not drop the stdin handle.
Examples
use async_process::Command;
let mut child = Command::new("ls").spawn()?;
match child.try_status()? {
None => println!("still running"),
Some(status) => println!("exited with: {}", status),
}
sourcepub fn status(&mut self) -> impl Future<Output = Result<ExitStatus, Error>>
pub fn status(&mut self) -> impl Future<Output = Result<ExitStatus, Error>>
Drops the stdin handle and waits for the process to exit.
Closing the stdin of the process helps avoid deadlocks. It ensures that the process does not block waiting for input from the parent process while the parent waits for the child to exit.
Examples
use async_process::{Command, Stdio};
let mut child = Command::new("cp")
.arg("a.txt")
.arg("b.txt")
.spawn()?;
println!("exit status: {}", child.status().await?);
sourcepub fn output(self) -> impl Future<Output = Result<Output, Error>>
pub fn output(self) -> impl Future<Output = Result<Output, Error>>
Drops the stdin handle and collects the output of the process.
Closing the stdin of the process helps avoid deadlocks. It ensures that the process does not block waiting for input from the parent process while the parent waits for the child to exit.
In order to capture the output of the process, Command::stdout()
and
Command::stderr()
must be configured with Stdio::piped()
.
Examples
use async_process::{Command, Stdio};
let child = Command::new("ls")
.stdout(Stdio::piped())
.stderr(Stdio::piped())
.spawn()?;
let out = child.output().await?;
Trait Implementations
Auto Trait Implementations
impl RefUnwindSafe for Child
impl Send for Child
impl Sync for Child
impl Unpin for Child
impl UnwindSafe for Child
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more