Crate tokio_process [−] [src]
An implementation of asynchronous process management for Tokio.
This crate provides a CommandExt
trait to enhance the functionality of the
Command
type in the standard library. The three methods provided by this
trait mirror the "spawning" methods in the standard library. The
CommandExt
trait in this crate, though, returns "future aware" types that
interoperate with Tokio. The asynchronous process support is provided
through signal handling on Unix and system APIs on Windows.
Examples
Here's an example program which will spawn echo hello world
and then wait
for it using an event loop.
extern crate futures; extern crate tokio_core; extern crate tokio_process; use std::process::Command; use futures::Future; use tokio_core::reactor::Core; use tokio_process::CommandExt; fn main() { // Create our own local event loop let mut core = Core::new().unwrap(); // Use the standard library's `Command` type to build a process and // then execute it via the `CommandExt` trait. let child = Command::new("echo").arg("hello").arg("world") .spawn_async(&core.handle()); // Make sure our child succeeded in spawning let child = child.expect("failed to spawn"); match core.run(child) { Ok(status) => println!("exit status: {}", status), Err(e) => panic!("failed to wait for exit: {}", e), } }
Next, let's take a look at an example where we not only spawn echo hello world
but we also capture its output.
extern crate futures; extern crate tokio_core; extern crate tokio_process; use std::process::Command; use futures::Future; use tokio_core::reactor::Core; use tokio_process::CommandExt; fn main() { let mut core = Core::new().unwrap(); // Like above, but use `output_async` which returns a future instead of // immediately returning the `Child`. let output = Command::new("echo").arg("hello").arg("world") .output_async(&core.handle()); let output = core.run(output).expect("failed to collect output"); assert!(output.status.success()); assert_eq!(output.stdout, b"hello world\n"); }
Caveats
While similar to the standard library, this crate's Child
type differs
importantly in the behavior of drop
. In the standard library, a child
process will continue running after the instance of std::process::Child
is dropped. In this crate, however, because tokio_process::Child
is a
future of the child's ExitStatus
, a child process is terminated if
tokio_process::Child
is dropped. The behavior of the standard library can
be regained with the Child::forget
method.
Structs
Child |
Representation of a child process spawned onto an event loop. |
ChildStderr |
The standard error stream for spawned children. |
ChildStdin |
The standard input stream for spawned children. |
ChildStdout |
The standard output stream for spawned children. |
OutputAsync |
Future returned by the |
StatusAsync |
Future returned by the |
WaitWithOutput |
Future returned from the |
Traits
CommandExt |
Extensions provided by this crate to the |