use std::fmt::Display;
#[derive(Debug)]
pub enum Wait {
WaitFailure(i32),
WNoHangExit,
ErrnoNotFound,
}
impl Display for Wait {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str(match *self {
Wait::ErrnoNotFound => "errno not found!",
_ => "exec failed!",
})
}
}
impl Wait {
pub fn children() -> Result<(libc::pid_t, libc::c_int), Wait> {
let mut status = 0;
let result = unsafe { libc::wait(&mut status as *mut libc::c_int) };
let errno = unsafe { libc::__errno_location() };
if errno == std::ptr::null_mut::<libc::c_int>() {
Err(Wait::ErrnoNotFound)
} else {
match result {
-1 => Err(Wait::WaitFailure(unsafe { *errno })),
_ => Ok((result, status)),
}
}
}
pub fn children_with(
pid: libc::pid_t,
options: libc::c_int,
) -> Result<(libc::pid_t, libc::c_int), Wait> {
let mut w_status = 0;
let result = unsafe { libc::waitpid(pid, &mut w_status as *mut libc::c_int, options) };
let errno = unsafe { libc::__errno_location() };
if errno == std::ptr::null_mut::<libc::c_int>() {
Err(Wait::ErrnoNotFound)
} else {
match result {
0 if options & libc::WNOHANG != 0 => Err(Wait::WNoHangExit),
-1 => Err(Wait::WaitFailure(unsafe { *errno })),
_ => Ok((result, w_status)),
}
}
}
}