6c1add8b73
* Prototype support for virtual uinput devices * Tidy uinput a bit * Have all the evtest examples use the same args/prompt code * Switch to libc uinput* structs * Use InputId in uinput, use libc _CNT constants * Don't use align_to_mut * Only check /dev/input/eventN files * Spelling fixup * Fix compilation error * Ah, there we go. Much better. Co-authored-by: Jeff Hiner <jeff-hiner@users.noreply.github.com> Co-authored-by: Noah <33094578+coolreader18@users.noreply.github.com>
81 lines
2.3 KiB
Rust
81 lines
2.3 KiB
Rust
//! This example demonstrates how to use the evdev crate with a nonblocking file descriptor.
|
|
//!
|
|
//! Note that for this implementation the caller is responsible for ensuring the underlying
|
|
//! Device file descriptor is set to O_NONBLOCK. The caller must also create the epoll descriptor,
|
|
//! bind it, check for EAGAIN returns from fetch_events_*, call epoll_wait as appropriate, and
|
|
//! clean up the epoll file descriptor when finished.
|
|
|
|
use nix::{
|
|
fcntl::{FcntlArg, OFlag},
|
|
sys::epoll,
|
|
};
|
|
use std::os::unix::io::{AsRawFd, RawFd};
|
|
|
|
// cli/"tui" shared between the evtest examples
|
|
mod _pick_device;
|
|
|
|
fn main() -> Result<(), Box<dyn std::error::Error>> {
|
|
let mut d = _pick_device::pick_device();
|
|
println!("{}", d);
|
|
|
|
let raw_fd = d.as_raw_fd();
|
|
// Set nonblocking
|
|
nix::fcntl::fcntl(raw_fd, FcntlArg::F_SETFL(OFlag::O_NONBLOCK))?;
|
|
|
|
// Create epoll handle and attach raw_fd
|
|
let epoll_fd = Epoll::new(epoll::epoll_create1(
|
|
epoll::EpollCreateFlags::EPOLL_CLOEXEC,
|
|
)?);
|
|
let mut event = epoll::EpollEvent::new(epoll::EpollFlags::EPOLLIN, 0);
|
|
epoll::epoll_ctl(
|
|
epoll_fd.as_raw_fd(),
|
|
epoll::EpollOp::EpollCtlAdd,
|
|
raw_fd,
|
|
Some(&mut event),
|
|
)?;
|
|
|
|
// We don't care about these, but the kernel wants to fill them.
|
|
let mut events = [epoll::EpollEvent::empty(); 2];
|
|
|
|
println!("Events:");
|
|
loop {
|
|
match d.fetch_events() {
|
|
Ok(iterator) => {
|
|
for ev in iterator {
|
|
println!("{:?}", ev);
|
|
}
|
|
}
|
|
Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
|
|
// Wait forever for bytes available on raw_fd
|
|
epoll::epoll_wait(epoll_fd.as_raw_fd(), &mut events, -1)?;
|
|
}
|
|
Err(e) => {
|
|
eprintln!("{}", e);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
// The rest here is to ensure the epoll handle is cleaned up properly.
|
|
// You can also use the epoll crate, if you prefer.
|
|
struct Epoll(RawFd);
|
|
|
|
impl Epoll {
|
|
pub(crate) fn new(fd: RawFd) -> Self {
|
|
Epoll(fd)
|
|
}
|
|
}
|
|
|
|
impl AsRawFd for Epoll {
|
|
fn as_raw_fd(&self) -> RawFd {
|
|
self.0
|
|
}
|
|
}
|
|
|
|
impl Drop for Epoll {
|
|
fn drop(&mut self) {
|
|
let _ = nix::unistd::close(self.0);
|
|
}
|
|
}
|