third_party/rust_crates/vendor/nix/src/pty.rs - fuchsia - Git at Google

 //! Create master and slave virtual pseudo-terminals (PTYs)

 pub use libc::pid_t as SessionId;
 pub use libc::winsize as Winsize;

 use std::ffi::CStr;
 use std::io;
 use std::mem;
 use std::os::unix::prelude::*;

 use crate::sys::termios::Termios;
 use crate::unistd::{self, ForkResult, Pid};
 use crate::{Result, Error, fcntl};
 use crate::errno::Errno;

 /// Representation of a master/slave pty pair
 ///
 /// This is returned by `openpty`.  Note that this type does *not* implement `Drop`, so the user
 /// must manually close the file descriptors.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub struct OpenptyResult {
     /// The master port in a virtual pty pair
     pub master: RawFd,
     /// The slave port in a virtual pty pair
     pub slave: RawFd,
 }

 /// Representation of a master with a forked pty
 ///
 /// This is returned by `forkpty`. Note that this type does *not* implement `Drop`, so the user
 /// must manually close the file descriptors.
 #[derive(Clone, Copy, Debug)]
 pub struct ForkptyResult {
     /// The master port in a virtual pty pair
     pub master: RawFd,
     /// Metadata about forked process
     pub fork_result: ForkResult,
 }


 /// Representation of the Master device in a master/slave pty pair
 ///
 /// While this datatype is a thin wrapper around `RawFd`, it enforces that the available PTY
 /// functions are given the correct file descriptor. Additionally this type implements `Drop`,
 /// so that when it's consumed or goes out of scope, it's automatically cleaned-up.
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct PtyMaster(RawFd);

 impl AsRawFd for PtyMaster {
     fn as_raw_fd(&self) -> RawFd {
         self.0
     }
 }

 impl IntoRawFd for PtyMaster {
     fn into_raw_fd(self) -> RawFd {
         let fd = self.0;
         mem::forget(self);
         fd
     }
 }

 impl Drop for PtyMaster {
     fn drop(&mut self) {
         // On drop, we ignore errors like EINTR and EIO because there's no clear
         // way to handle them, we can't return anything, and (on FreeBSD at
         // least) the file descriptor is deallocated in these cases.  However,
         // we must panic on EBADF, because it is always an error to close an
         // invalid file descriptor.  That frequently indicates a double-close
         // condition, which can cause confusing errors for future I/O
         // operations.
         let e = unistd::close(self.0);
         if e == Err(Error::Sys(Errno::EBADF)) {
             panic!("Closing an invalid file descriptor!");
         };
     }
 }

 impl io::Read for PtyMaster {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         unistd::read(self.0, buf).map_err(|e| e.as_errno().unwrap().into())
     }
 }

 impl io::Write for PtyMaster {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         unistd::write(self.0, buf).map_err(|e| e.as_errno().unwrap().into())
     }
     fn flush(&mut self) -> io::Result<()> {
         Ok(())
     }
 }

 /// Grant access to a slave pseudoterminal (see
 /// [`grantpt(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/grantpt.html))
 ///
 /// `grantpt()` changes the mode and owner of the slave pseudoterminal device corresponding to the
 /// master pseudoterminal referred to by `fd`. This is a necessary step towards opening the slave.
 #[inline]
 pub fn grantpt(fd: &PtyMaster) -> Result<()> {
     if unsafe { libc::grantpt(fd.as_raw_fd()) } < 0 {
         return Err(Error::last());
     }

     Ok(())
 }

 /// Open a pseudoterminal device (see
 /// [`posix_openpt(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_openpt.html))
 ///
 /// `posix_openpt()` returns a file descriptor to an existing unused pseuterminal master device.
 ///
 /// # Examples
 ///
 /// A common use case with this function is to open both a master and slave PTY pair. This can be
 /// done as follows:
 ///
 /// ```
 /// use std::path::Path;
 /// use nix::fcntl::{OFlag, open};
 /// use nix::pty::{grantpt, posix_openpt, ptsname, unlockpt};
 /// use nix::sys::stat::Mode;
 ///
 /// # #[allow(dead_code)]
 /// # fn run() -> nix::Result<()> {
 /// // Open a new PTY master
 /// let master_fd = posix_openpt(OFlag::O_RDWR)?;
 ///
 /// // Allow a slave to be generated for it
 /// grantpt(&master_fd)?;
 /// unlockpt(&master_fd)?;
 ///
 /// // Get the name of the slave
 /// let slave_name = unsafe { ptsname(&master_fd) }?;
 ///
 /// // Try to open the slave
 /// let _slave_fd = open(Path::new(&slave_name), OFlag::O_RDWR, Mode::empty())?;
 /// # Ok(())
 /// # }
 /// ```
 #[inline]
 pub fn posix_openpt(flags: fcntl::OFlag) -> Result<PtyMaster> {
     let fd = unsafe {
         libc::posix_openpt(flags.bits())
     };

     if fd < 0 {
         return Err(Error::last());
     }

     Ok(PtyMaster(fd))
 }

 /// Get the name of the slave pseudoterminal (see
 /// [`ptsname(3)`](http://man7.org/linux/man-pages/man3/ptsname.3.html))
 ///
 /// `ptsname()` returns the name of the slave pseudoterminal device corresponding to the master
 /// referred to by `fd`.
 ///
 /// This value is useful for opening the slave pty once the master has already been opened with
 /// `posix_openpt()`.
 ///
 /// # Safety
 ///
 /// `ptsname()` mutates global variables and is *not* threadsafe.
 /// Mutating global variables is always considered `unsafe` by Rust and this
 /// function is marked as `unsafe` to reflect that.
 ///
 /// For a threadsafe and non-`unsafe` alternative on Linux, see `ptsname_r()`.
 #[inline]
 pub unsafe fn ptsname(fd: &PtyMaster) -> Result<String> {
     let name_ptr = libc::ptsname(fd.as_raw_fd());
     if name_ptr.is_null() {
         return Err(Error::last());
     }

     let name = CStr::from_ptr(name_ptr);
     Ok(name.to_string_lossy().into_owned())
 }

 /// Get the name of the slave pseudoterminal (see
 /// [`ptsname(3)`](http://man7.org/linux/man-pages/man3/ptsname.3.html))
 ///
 /// `ptsname_r()` returns the name of the slave pseudoterminal device corresponding to the master
 /// referred to by `fd`. This is the threadsafe version of `ptsname()`, but it is not part of the
 /// POSIX standard and is instead a Linux-specific extension.
 ///
 /// This value is useful for opening the slave ptty once the master has already been opened with
 /// `posix_openpt()`.
 #[cfg(any(target_os = "android", target_os = "linux"))]
 #[inline]
 pub fn ptsname_r(fd: &PtyMaster) -> Result<String> {
     let mut name_buf = vec![0u8; 64];
     let name_buf_ptr = name_buf.as_mut_ptr() as *mut libc::c_char;
     if unsafe { libc::ptsname_r(fd.as_raw_fd(), name_buf_ptr, name_buf.capacity()) } != 0 {
         return Err(Error::last());
     }

     // Find the first null-character terminating this string. This is guaranteed to succeed if the
     // return value of `libc::ptsname_r` is 0.
     let null_index = name_buf.iter().position(|c| *c == b'\0').unwrap();
     name_buf.truncate(null_index);

     let name = String::from_utf8(name_buf)?;
     Ok(name)
 }

 /// Unlock a pseudoterminal master/slave pseudoterminal pair (see
 /// [`unlockpt(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/unlockpt.html))
 ///
 /// `unlockpt()` unlocks the slave pseudoterminal device corresponding to the master pseudoterminal
 /// referred to by `fd`. This must be called before trying to open the slave side of a
 /// pseuoterminal.
 #[inline]
 pub fn unlockpt(fd: &PtyMaster) -> Result<()> {
     if unsafe { libc::unlockpt(fd.as_raw_fd()) } < 0 {
         return Err(Error::last());
     }

     Ok(())
 }


 /// Create a new pseudoterminal, returning the slave and master file descriptors
 /// in `OpenptyResult`
 /// (see [`openpty`](http://man7.org/linux/man-pages/man3/openpty.3.html)).
 ///
 /// If `winsize` is not `None`, the window size of the slave will be set to
 /// the values in `winsize`. If `termios` is not `None`, the pseudoterminal's
 /// terminal settings of the slave will be set to the values in `termios`.
 #[inline]
 pub fn openpty<'a, 'b, T: Into<Option<&'a Winsize>>, U: Into<Option<&'b Termios>>>(winsize: T, termios: U) -> Result<OpenptyResult> {
     use std::ptr;

     let mut slave = mem::MaybeUninit::<libc::c_int>::uninit();
     let mut master = mem::MaybeUninit::<libc::c_int>::uninit();
     let ret = {
         match (termios.into(), winsize.into()) {
             (Some(termios), Some(winsize)) => {
                 let inner_termios = termios.get_libc_termios();
                 unsafe {
                     libc::openpty(
                         master.as_mut_ptr(),
                         slave.as_mut_ptr(),
                         ptr::null_mut(),
                         &*inner_termios as *const libc::termios as *mut _,
                         winsize as *const Winsize as *mut _,
                     )
                 }
             }
             (None, Some(winsize)) => {
                 unsafe {
                     libc::openpty(
                         master.as_mut_ptr(),
                         slave.as_mut_ptr(),
                         ptr::null_mut(),
                         ptr::null_mut(),
                         winsize as *const Winsize as *mut _,
                     )
                 }
             }
             (Some(termios), None) => {
                 let inner_termios = termios.get_libc_termios();
                 unsafe {
                     libc::openpty(
                         master.as_mut_ptr(),
                         slave.as_mut_ptr(),
                         ptr::null_mut(),
                         &*inner_termios as *const libc::termios as *mut _,
                         ptr::null_mut(),
                     )
                 }
             }
             (None, None) => {
                 unsafe {
                     libc::openpty(
                         master.as_mut_ptr(),
                         slave.as_mut_ptr(),
                         ptr::null_mut(),
                         ptr::null_mut(),
                         ptr::null_mut(),
                     )
                 }
             }
         }
     };

     Errno::result(ret)?;

     unsafe {
         Ok(OpenptyResult {
             master: master.assume_init(),
             slave: slave.assume_init(),
         })
     }
 }

 /// Create a new pseudoterminal, returning the master file descriptor and forked pid.
 /// in `ForkptyResult`
 /// (see [`forkpty`](http://man7.org/linux/man-pages/man3/forkpty.3.html)).
 ///
 /// If `winsize` is not `None`, the window size of the slave will be set to
 /// the values in `winsize`. If `termios` is not `None`, the pseudoterminal's
 /// terminal settings of the slave will be set to the values in `termios`.
 pub fn forkpty<'a, 'b, T: Into<Option<&'a Winsize>>, U: Into<Option<&'b Termios>>>(
     winsize: T,
     termios: U,
 ) -> Result<ForkptyResult> {
     use std::ptr;

     let mut master = mem::MaybeUninit::<libc::c_int>::uninit();

     let term = match termios.into() {
         Some(termios) => {
             let inner_termios = termios.get_libc_termios();
             &*inner_termios as *const libc::termios as *mut _
         },
         None => ptr::null_mut(),
     };

     let win = winsize
         .into()
         .map(|ws| ws as *const Winsize as *mut _)
         .unwrap_or(ptr::null_mut());

     let res = unsafe {
         libc::forkpty(master.as_mut_ptr(), ptr::null_mut(), term, win)
     };

     let fork_result = Errno::result(res).map(|res| match res {
         0 => ForkResult::Child,
         res => ForkResult::Parent { child: Pid::from_raw(res) },
     })?;

     unsafe {
         Ok(ForkptyResult {
             master: master.assume_init(),
             fork_result,
         })
     }
 }
	//! Create master and slave virtual pseudo-terminals (PTYs)

	pub use libc::pid_t as SessionId;
	pub use libc::winsize as Winsize;

	use std::ffi::CStr;
	use std::io;
	use std::mem;
	use std::os::unix::prelude::*;

	use crate::sys::termios::Termios;
	use crate::unistd::{self, ForkResult, Pid};
	use crate::{Result, Error, fcntl};
	use crate::errno::Errno;

	/// Representation of a master/slave pty pair
	///
	/// This is returned by `openpty`. Note that this type does not implement `Drop`, so the user
	/// must manually close the file descriptors.
	#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
	pub struct OpenptyResult {
	/// The master port in a virtual pty pair
	pub master: RawFd,
	/// The slave port in a virtual pty pair
	pub slave: RawFd,
	}

	/// Representation of a master with a forked pty
	///
	/// This is returned by `forkpty`. Note that this type does not implement `Drop`, so the user
	/// must manually close the file descriptors.
	#[derive(Clone, Copy, Debug)]
	pub struct ForkptyResult {
	/// The master port in a virtual pty pair
	pub master: RawFd,
	/// Metadata about forked process
	pub fork_result: ForkResult,
	}


	/// Representation of the Master device in a master/slave pty pair
	///
	/// While this datatype is a thin wrapper around `RawFd`, it enforces that the available PTY
	/// functions are given the correct file descriptor. Additionally this type implements `Drop`,
	/// so that when it's consumed or goes out of scope, it's automatically cleaned-up.
	#[derive(Clone, Debug, Eq, Hash, PartialEq)]
	pub struct PtyMaster(RawFd);

	impl AsRawFd for PtyMaster {
	fn as_raw_fd(&self) -> RawFd {
	self.0
	}
	}

	impl IntoRawFd for PtyMaster {
	fn into_raw_fd(self) -> RawFd {
	let fd = self.0;
	mem::forget(self);
	fd
	}
	}

	impl Drop for PtyMaster {
	fn drop(&mut self) {
	// On drop, we ignore errors like EINTR and EIO because there's no clear
	// way to handle them, we can't return anything, and (on FreeBSD at
	// least) the file descriptor is deallocated in these cases. However,
	// we must panic on EBADF, because it is always an error to close an
	// invalid file descriptor. That frequently indicates a double-close
	// condition, which can cause confusing errors for future I/O
	// operations.
	let e = unistd::close(self.0);
	if e == Err(Error::Sys(Errno::EBADF)) {
	panic!("Closing an invalid file descriptor!");
	};
	}
	}

	impl io::Read for PtyMaster {
	fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
	unistd::read(self.0, buf).map_err(\|e\| e.as_errno().unwrap().into())
	}
	}

	impl io::Write for PtyMaster {
	fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
	unistd::write(self.0, buf).map_err(\|e\| e.as_errno().unwrap().into())
	}
	fn flush(&mut self) -> io::Result<()> {
	Ok(())
	}
	}

	/// Grant access to a slave pseudoterminal (see
	/// [`grantpt(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/grantpt.html))
	///
	/// `grantpt()` changes the mode and owner of the slave pseudoterminal device corresponding to the
	/// master pseudoterminal referred to by `fd`. This is a necessary step towards opening the slave.
	#[inline]
	pub fn grantpt(fd: &PtyMaster) -> Result<()> {
	if unsafe { libc::grantpt(fd.as_raw_fd()) } < 0 {
	return Err(Error::last());
	}

	Ok(())
	}

	/// Open a pseudoterminal device (see
	/// [`posix_openpt(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_openpt.html))
	///
	/// `posix_openpt()` returns a file descriptor to an existing unused pseuterminal master device.
	///
	/// # Examples
	///
	/// A common use case with this function is to open both a master and slave PTY pair. This can be
	/// done as follows:
	///
	/// ```
	/// use std::path::Path;
	/// use nix::fcntl::{OFlag, open};
	/// use nix::pty::{grantpt, posix_openpt, ptsname, unlockpt};
	/// use nix::sys::stat::Mode;
	///
	/// # #[allow(dead_code)]
	/// # fn run() -> nix::Result<()> {
	/// // Open a new PTY master
	/// let master_fd = posix_openpt(OFlag::O_RDWR)?;
	///
	/// // Allow a slave to be generated for it
	/// grantpt(&master_fd)?;
	/// unlockpt(&master_fd)?;
	///
	/// // Get the name of the slave
	/// let slave_name = unsafe { ptsname(&master_fd) }?;
	///
	/// // Try to open the slave
	/// let _slave_fd = open(Path::new(&slave_name), OFlag::O_RDWR, Mode::empty())?;
	/// # Ok(())
	/// # }
	/// ```
	#[inline]
	pub fn posix_openpt(flags: fcntl::OFlag) -> Result<PtyMaster> {
	let fd = unsafe {
	libc::posix_openpt(flags.bits())
	};

	if fd < 0 {
	return Err(Error::last());
	}

	Ok(PtyMaster(fd))
	}

	/// Get the name of the slave pseudoterminal (see
	/// [`ptsname(3)`](http://man7.org/linux/man-pages/man3/ptsname.3.html))
	///
	/// `ptsname()` returns the name of the slave pseudoterminal device corresponding to the master
	/// referred to by `fd`.
	///
	/// This value is useful for opening the slave pty once the master has already been opened with
	/// `posix_openpt()`.
	///
	/// # Safety
	///
	/// `ptsname()` mutates global variables and is not threadsafe.
	/// Mutating global variables is always considered `unsafe` by Rust and this
	/// function is marked as `unsafe` to reflect that.
	///
	/// For a threadsafe and non-`unsafe` alternative on Linux, see `ptsname_r()`.
	#[inline]
	pub unsafe fn ptsname(fd: &PtyMaster) -> Result<String> {
	let name_ptr = libc::ptsname(fd.as_raw_fd());
	if name_ptr.is_null() {
	return Err(Error::last());
	}

	let name = CStr::from_ptr(name_ptr);
	Ok(name.to_string_lossy().into_owned())
	}

	/// Get the name of the slave pseudoterminal (see
	/// [`ptsname(3)`](http://man7.org/linux/man-pages/man3/ptsname.3.html))
	///
	/// `ptsname_r()` returns the name of the slave pseudoterminal device corresponding to the master
	/// referred to by `fd`. This is the threadsafe version of `ptsname()`, but it is not part of the
	/// POSIX standard and is instead a Linux-specific extension.
	///
	/// This value is useful for opening the slave ptty once the master has already been opened with
	/// `posix_openpt()`.
	#[cfg(any(target_os = "android", target_os = "linux"))]
	#[inline]
	pub fn ptsname_r(fd: &PtyMaster) -> Result<String> {
	let mut name_buf = vec![0u8; 64];
	let name_buf_ptr = name_buf.as_mut_ptr() as *mut libc::c_char;
	if unsafe { libc::ptsname_r(fd.as_raw_fd(), name_buf_ptr, name_buf.capacity()) } != 0 {
	return Err(Error::last());
	}

	// Find the first null-character terminating this string. This is guaranteed to succeed if the
	// return value of `libc::ptsname_r` is 0.
	let null_index = name_buf.iter().position(\|c\| *c == b'\0').unwrap();
	name_buf.truncate(null_index);

	let name = String::from_utf8(name_buf)?;
	Ok(name)
	}

	/// Unlock a pseudoterminal master/slave pseudoterminal pair (see
	/// [`unlockpt(3)`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/unlockpt.html))
	///
	/// `unlockpt()` unlocks the slave pseudoterminal device corresponding to the master pseudoterminal
	/// referred to by `fd`. This must be called before trying to open the slave side of a
	/// pseuoterminal.
	#[inline]
	pub fn unlockpt(fd: &PtyMaster) -> Result<()> {
	if unsafe { libc::unlockpt(fd.as_raw_fd()) } < 0 {
	return Err(Error::last());
	}

	Ok(())
	}


	/// Create a new pseudoterminal, returning the slave and master file descriptors
	/// in `OpenptyResult`
	/// (see [`openpty`](http://man7.org/linux/man-pages/man3/openpty.3.html)).
	///
	/// If `winsize` is not `None`, the window size of the slave will be set to
	/// the values in `winsize`. If `termios` is not `None`, the pseudoterminal's
	/// terminal settings of the slave will be set to the values in `termios`.
	#[inline]
	pub fn openpty<'a, 'b, T: Into<Option<&'a Winsize>>, U: Into<Option<&'b Termios>>>(winsize: T, termios: U) -> Result<OpenptyResult> {
	use std::ptr;

	let mut slave = mem::MaybeUninit::<libc::c_int>::uninit();
	let mut master = mem::MaybeUninit::<libc::c_int>::uninit();
	let ret = {
	match (termios.into(), winsize.into()) {
	(Some(termios), Some(winsize)) => {
	let inner_termios = termios.get_libc_termios();
	unsafe {
	libc::openpty(
	master.as_mut_ptr(),
	slave.as_mut_ptr(),
	ptr::null_mut(),
	&inner_termios as const libc::termios as *mut _,
	winsize as const Winsize as mut _,
	)
	}
	}
	(None, Some(winsize)) => {
	unsafe {
	libc::openpty(
	master.as_mut_ptr(),
	slave.as_mut_ptr(),
	ptr::null_mut(),
	ptr::null_mut(),
	winsize as const Winsize as mut _,
	)
	}
	}
	(Some(termios), None) => {
	let inner_termios = termios.get_libc_termios();
	unsafe {
	libc::openpty(
	master.as_mut_ptr(),
	slave.as_mut_ptr(),
	ptr::null_mut(),
	&inner_termios as const libc::termios as *mut _,
	ptr::null_mut(),
	)
	}
	}
	(None, None) => {
	unsafe {
	libc::openpty(
	master.as_mut_ptr(),
	slave.as_mut_ptr(),
	ptr::null_mut(),
	ptr::null_mut(),
	ptr::null_mut(),
	)
	}
	}
	}
	};

	Errno::result(ret)?;

	unsafe {
	Ok(OpenptyResult {
	master: master.assume_init(),
	slave: slave.assume_init(),
	})
	}
	}

	/// Create a new pseudoterminal, returning the master file descriptor and forked pid.
	/// in `ForkptyResult`
	/// (see [`forkpty`](http://man7.org/linux/man-pages/man3/forkpty.3.html)).
	///
	/// If `winsize` is not `None`, the window size of the slave will be set to
	/// the values in `winsize`. If `termios` is not `None`, the pseudoterminal's
	/// terminal settings of the slave will be set to the values in `termios`.
	pub fn forkpty<'a, 'b, T: Into<Option<&'a Winsize>>, U: Into<Option<&'b Termios>>>(
	winsize: T,
	termios: U,
	) -> Result<ForkptyResult> {
	use std::ptr;

	let mut master = mem::MaybeUninit::<libc::c_int>::uninit();

	let term = match termios.into() {
	Some(termios) => {
	let inner_termios = termios.get_libc_termios();
	&inner_termios as const libc::termios as *mut _
	},
	None => ptr::null_mut(),
	};

	let win = winsize
	.into()
	.map(\|ws\| ws as const Winsize as mut _)
	.unwrap_or(ptr::null_mut());

	let res = unsafe {
	libc::forkpty(master.as_mut_ptr(), ptr::null_mut(), term, win)
	};

	let fork_result = Errno::result(res).map(\|res\| match res {
	0 => ForkResult::Child,
	res => ForkResult::Parent { child: Pid::from_raw(res) },
	})?;

	unsafe {
	Ok(ForkptyResult {
	master: master.assume_init(),
	fork_result,
	})
	}
	}