smol/examples/linux-inotify.rs

58 lines
1.7 KiB
Rust

//! Uses the `inotify` crate to watch for changes in the current directory.
//!
//! Run with:
//!
//! ```
//! cargo run --example linux-inotify
//! ```
#[cfg(target_os = "linux")]
fn main() -> std::io::Result<()> {
use std::ffi::OsString;
use std::os::unix::io::AsFd;
use inotify::{EventMask, Inotify, WatchMask};
use smol::{io, Async};
type Event = (OsString, EventMask);
/// Reads some events without blocking.
///
/// If there are no events, an [`io::ErrorKind::WouldBlock`] error is returned.
fn read_op(inotify: &mut Inotify) -> io::Result<Vec<Event>> {
let mut buffer = [0; 1024];
let events = inotify
.read_events(&mut buffer)?
.filter_map(|ev| ev.name.map(|name| (name.to_owned(), ev.mask)))
.collect::<Vec<_>>();
if events.is_empty() {
Err(io::ErrorKind::WouldBlock.into())
} else {
Ok(events)
}
}
smol::block_on(async {
// Watch events in the current directory.
let mut inotify = Inotify::init()?;
let source = Async::new(inotify.as_fd().try_clone_to_owned()?)?;
inotify.watches().add(".", WatchMask::ALL_EVENTS)?;
println!("Watching for filesystem events in the current directory...");
println!("Try opening a file to trigger some events.");
println!();
// Wait for events in a loop and print them on the screen.
loop {
for event in source.read_with(|_| read_op(&mut inotify)).await? {
println!("{:?}", event);
}
}
})
}
#[cfg(not(target_os = "linux"))]
fn main() {
println!("This example works only on Linux!");
}