//! Terminal-related `ioctl` functions.

#![allow(unsafe_code)]

use crate::fd::AsFd;

use crate::{backend, io, ioctl};

use backend::c;

/// `ioctl(fd, TIOCEXCL)`—Enables exclusive mode on a terminal.

///

/// In exclusive mode, subsequent unprivileged `open` calls on the terminal

/// device fail with [`io::Errno::BUSY`].

///

/// # References

///  - [Linux]

///  - [FreeBSD]

///  - [NetBSD]

///  - [OpenBSD]

///

/// [Linux]: https://man7.org/linux/man-pages/man4/tty_ioctl.4.html

/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=tty&sektion=4

/// [NetBSD]: https://man.netbsd.org/tty.4

/// [OpenBSD]: https://man.openbsd.org/tty.4

#[cfg(not(any(

    windows,

    target_os = "horizon",

    target_os = "redox",

    target_os = "wasi"

)))]

#[inline]

#[doc(alias = "TIOCEXCL")]

pub fn ioctl_tiocexcl<Fd: AsFd>(fd: Fd) -> io::Result<()> {

    // SAFETY: `TIOCEXCL` is a no-argument setter opcode.

    unsafe {

        let ctl = ioctl::NoArg::<{ c::TIOCEXCL as _ }>::new();

        ioctl::ioctl(fd, ctl)

    }

}

/// `ioctl(fd, TIOCNXCL)`—Disables exclusive mode on a terminal.

///

/// # References

///  - [Linux]

///  - [FreeBSD]

///  - [NetBSD]

///  - [OpenBSD]

///

/// [Linux]: https://man7.org/linux/man-pages/man4/tty_ioctl.4.html

/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=tty&sektion=4

/// [NetBSD]: https://man.netbsd.org/tty.4

/// [OpenBSD]: https://man.openbsd.org/tty.4

#[cfg(not(any(

    windows,

    target_os = "horizon",

    target_os = "redox",

    target_os = "wasi"

)))]

#[inline]

#[doc(alias = "TIOCNXCL")]

pub fn ioctl_tiocnxcl<Fd: AsFd>(fd: Fd) -> io::Result<()> {

    // SAFETY: `TIOCNXCL` is a no-argument setter opcode.

    unsafe {

        let ctl = ioctl::NoArg::<{ c::TIOCNXCL as _ }>::new();

        ioctl::ioctl(fd, ctl)

    }

}