Function tokio::signal::ctrl_c

source ·
pub async fn ctrl_c() -> Result<()>
Available on crate feature signal only.
Expand description

Completes when a “ctrl-c” notification is sent to the process.

While signals are handled very differently between Unix and Windows, both platforms support receiving a signal on “ctrl-c”. This function provides a portable API for receiving this notification.

Once the returned future is polled, a listener is registered. The future will complete on the first received ctrl-c after the initial call to either Future::poll or .await.

Caveats

On Unix platforms, the first time that a Signal instance is registered for a particular signal kind, an OS signal-handler is installed which replaces the default platform behavior when that signal is received, for the duration of the entire process.

For example, Unix systems will terminate a process by default when it receives a signal generated by “CTRL+C” on the terminal. But, when a ctrl_c stream is created to listen for this signal, the time it arrives, it will be translated to a stream event, and the process will continue to execute. Even if this Signal instance is dropped, subsequent SIGINT deliveries will end up captured by Tokio, and the default platform behavior will NOT be reset.

Thus, applications should take care to ensure the expected signal behavior occurs as expected after listening for specific signals.

Examples

use tokio::signal;

#[tokio::main]
async fn main() {
    println!("waiting for ctrl-c");

    signal::ctrl_c().await.expect("failed to listen for event");

    println!("received ctrl-c event");
}

Listen in the background:

tokio::spawn(async move {
    tokio::signal::ctrl_c().await.unwrap();
    // Your handler here
});