Struct commandspec::SpawnGuard

pub struct SpawnGuard(pub Child);

Methods from Deref<Target = Child>

pub fn kill(&mut self) -> Result<(), Error>

Forces the child process to exit. If the child has already exited, an InvalidInput error is returned.

The mapping to ErrorKinds is not part of the compatibility contract of the function, especially the Other kind might change to more specific kinds in the future.

This is equivalent to sending a SIGKILL on Unix platforms.

Examples

Basic usage:

use std::process::Command;

let mut command = Command::new("yes");
if let Ok(mut child) = command.spawn() {
    child.kill().expect("command wasn't running");
} else {
    println!("yes command didn't start");
}

pub fn id(&self) -> u32

Returns the OS-assigned process identifier associated with this child.

Examples

Basic usage:

use std::process::Command;

let mut command = Command::new("ls");
if let Ok(child) = command.spawn() {
    println!("Child's id is {}", child.id());
} else {
    println!("ls command didn't start");
}

pub fn wait(&mut self) -> Result<ExitStatus, Error>

Waits for the child to exit completely, returning the status that it exited with. This function will continue to have the same return value after it has been called at least once.

The stdin handle to the child process, if any, will be closed before waiting. This helps avoid deadlock: it ensures that the child does not block waiting for input from the parent, while the parent waits for the child to exit.

Examples

Basic usage:

use std::process::Command;

let mut command = Command::new("ls");
if let Ok(mut child) = command.spawn() {
    child.wait().expect("command wasn't running");
    println!("Child has finished its execution!");
} else {
    println!("ls command didn't start");
}

pub fn try_wait(&mut self) -> Result<Option<ExitStatus>, Error>

Attempts to collect the exit status of the child if it has already exited.

This function will not block the calling thread and will only advisorily check to see if the child process has exited or not. If the child has exited then on Unix the process id is reaped. This function is guaranteed to repeatedly return a successful exit status so long as the child has already exited.

If the child has exited, then Ok(Some(status)) is returned. If the exit status is not available at this time then Ok(None) is returned. If an error occurs, then that error is returned.

Note that unlike wait, this function will not attempt to drop stdin.

Examples

Basic usage:

use std::process::Command;

let mut child = Command::new("ls").spawn().unwrap();

match child.try_wait() {
    Ok(Some(status)) => println!("exited with: {}", status),
    Ok(None) => {
        println!("status not ready yet, let's really wait");
        let res = child.wait();
        println!("result: {:?}", res);
    }
    Err(e) => println!("error attempting to wait: {}", e),
}

Trait Implementations

impl Deref for SpawnGuard

type Target = Child

The resulting type after dereferencing.

fn deref(&self) -> &Child

Dereferences the value.

impl DerefMut for SpawnGuard

fn deref_mut(&mut self) -> &mut Child

Mutably dereferences the value.

impl Drop for SpawnGuard

fn drop(&mut self)

Executes the destructor for this type.