Crate watchexec

Watchexec: a library for utilities and programs which respond to (file, signal, etc) events primarily by launching or managing other programs.

Also see the CLI tool: https://github.com/watchexec/watchexec

This library is powered by Tokio.

The main way to use this crate involves constructing a Watchexec around a Config, then running it. Handlers (defined in Config) are used to hook into Watchexec at various points. The config can be changed at any time with the config field on your Watchexec instance.

It’s recommended to use the miette erroring library in applications, but all errors implement std::error::Error so your favourite error handling library can of course be used.

use miette::{IntoDiagnostic, Result};
use watchexec_signals::Signal;
use watchexec::Watchexec;

#[tokio::main]
async fn main() -> Result<()> {
    let wx = Watchexec::new(|mut action| {
        // print any events
        for event in action.events.iter() {
            eprintln!("EVENT: {event:?}");
        }

        // if Ctrl-C is received, quit
        if action.signals().any(|sig| sig == Signal::Interrupt) {
            action.quit();
        }

        action
    })?;

    // watch the current directory
    wx.config.pathset(["."]);

    wx.main().await.into_diagnostic()?;
    Ok(())
}

Alternatively, you can use the modules exposed by the crate and the external crates such as notify, clearscreen, process_wrap… to build something more advanced, at the cost of reimplementing the glue code.

Note that the library generates a lot of debug messaging with tracing. You should not enable printing even error-level log messages for this crate unless it’s for debugging. Instead, make use of the Config::on_error() method to define a handler for errors occurring at runtime that are meant for you to handle (by printing out or otherwise).

Re-exports

pub use crate::config::Config;

pub use watchexec_supervisor::command;

pub use watchexec_supervisor::job;

Modules

action

Processor responsible for receiving events, filtering them, and scheduling actions in response.

changeable

Changeable values.

config

Configuration and builders for crate::Watchexec.

error

Error types for critical, runtime, and specialised errors.

filter

The Filterer trait for event filtering.

paths

Utilities for paths and sets of paths.

sources

Sources of events.

Structs

ErrorHook

The environment given to the error handler.

Id

Unique opaque identifier.

WatchedPath

A path to watch.

Watchexec

The main watchexec runtime.