1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/// The path to the default TTY on linux
pub const TTY_PATH: &str = "/dev/tty";
#[cfg(unix)]
pub(crate) mod imp {
use std::{
io::{BufRead, Write},
os::unix::io::{AsRawFd, RawFd},
};
use nix::sys::{termios, termios::Termios};
use parking_lot::{const_mutex, lock_api::MutexGuard, Mutex, RawMutex};
use crate::{unix::TTY_PATH, Error, Mode, Options};
static TERM_STATE: Mutex<Option<Termios>> = const_mutex(None);
/// Ask the user given a `prompt`, returning the result.
pub(crate) fn ask(prompt: &str, Options { mode, .. }: &Options<'_>) -> Result<String, Error> {
match mode {
Mode::Disable => Err(Error::Disabled),
Mode::Hidden => {
let state = TERM_STATE.lock();
let mut in_out = std::fs::OpenOptions::new().write(true).read(true).open(TTY_PATH)?;
let restore = save_term_state_and_disable_echo(state, in_out.as_raw_fd())?;
in_out.write_all(prompt.as_bytes())?;
let mut buf_read = std::io::BufReader::with_capacity(64, in_out);
let mut out = String::with_capacity(64);
buf_read.read_line(&mut out)?;
out.pop();
if out.ends_with('\r') {
out.pop();
}
restore.now()?;
Ok(out)
}
Mode::Visible => {
let mut in_out = std::fs::OpenOptions::new().write(true).read(true).open(TTY_PATH)?;
in_out.write_all(prompt.as_bytes())?;
let mut buf_read = std::io::BufReader::with_capacity(64, in_out);
let mut out = String::with_capacity(64);
buf_read.read_line(&mut out)?;
Ok(out.trim_end().to_owned())
}
}
}
type TermiosGuard<'a> = MutexGuard<'a, RawMutex, Option<Termios>>;
struct RestoreTerminalStateOnDrop<'a> {
state: TermiosGuard<'a>,
fd: RawFd,
}
impl<'a> RestoreTerminalStateOnDrop<'a> {
fn now(mut self) -> Result<(), Error> {
let state = self.state.take().expect("BUG: we exist only if something is saved");
termios::tcsetattr(self.fd, termios::SetArg::TCSAFLUSH, &state)?;
Ok(())
}
}
impl<'a> Drop for RestoreTerminalStateOnDrop<'a> {
fn drop(&mut self) {
if let Some(state) = self.state.take() {
termios::tcsetattr(self.fd, termios::SetArg::TCSAFLUSH, &state).ok();
}
}
}
fn save_term_state_and_disable_echo(
mut state: TermiosGuard<'_>,
fd: RawFd,
) -> Result<RestoreTerminalStateOnDrop<'_>, Error> {
assert!(
state.is_none(),
"BUG: recursive calls are not possible and we restore afterwards"
);
let prev = termios::tcgetattr(fd)?;
let mut new = prev.clone();
*state = prev.into();
new.local_flags &= !termios::LocalFlags::ECHO;
new.local_flags |= termios::LocalFlags::ECHONL;
termios::tcsetattr(fd, termios::SetArg::TCSAFLUSH, &new)?;
Ok(RestoreTerminalStateOnDrop { fd, state })
}
}
|
