Add openpty()

Author: cactorium

CHANGELOG.md

@@ -12,6 +12,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   ([#551](https://github.com/nix-rust/nix/pull/551))
 - Added `nix::pty::{grantpt, posix_openpt, ptsname/ptsname_r, unlockpt}`
   ([#556](https://github.com/nix-rust/nix/pull/556)
+- Added `nix::ptr::openpty`
+  ([#456](https://github.com/nix-rust/nix/pull/456))
 
 ### Changed
 - Marked `sys::mman::{ mmap, munmap, madvise, munlock, msync }` as unsafe.

src/pty.rs

@@ -1,12 +1,26 @@
 //! Create master and slave virtual pseudo-terminals (PTYs)
 
+use libc;
+
+pub use libc::pid_t as SessionId;
+pub use libc::winsize as Winsize;
+
 use std::ffi::CStr;
 use std::mem;
 use std::os::unix::prelude::*;
+use std::os::unix::io::RawFd;
 
-use libc;
+use sys::termios::Termios;
+use {Errno, Result, Error, fcntl};
+
+/// Representation of a master/slave pty pair
+///
+/// This is returned by `openpty`
+pub struct OpenptyResult {
+    pub master: RawFd,
+    pub slave: RawFd,
+}
 
-use {Error, fcntl, Result};
 
 /// Representation of the Master device in a master/slave pty pair
 ///
@@ -162,3 +176,42 @@ pub fn unlockpt(fd: &PtyMaster) -> Result<()> {
 
     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: libc::c_int = -1;
+    let mut master: libc::c_int = -1;
+    let c_termios = match termios.into() {
+        Some(termios) => termios as *const Termios,
+        None => ptr::null() as *const Termios,
+    };
+    let c_winsize = match winsize.into() {
+        Some(ws) => ws as *const Winsize,
+        None => ptr::null() as *const Winsize,
+    };
+    let ret = unsafe {
+        libc::openpty(
+            &mut master as *mut libc::c_int,
+            &mut slave as *mut libc::c_int,
+            ptr::null_mut(),
+            c_termios as *mut libc::termios,
+            c_winsize as *mut Winsize)
+    };
+
+    Errno::result(ret)?;
+
+    Ok(OpenptyResult {
+        master: master,
+        slave: slave,
+    })
+}

test/test.rs

@@ -11,20 +11,18 @@ extern crate nix_test as nixtest;
 
 mod sys;
 mod test_fcntl;
+#[cfg(any(target_os = "linux"))]
+mod test_mq;
 mod test_net;
 mod test_nix_path;
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+mod test_poll;
+mod test_pty;
 #[cfg(any(target_os = "linux", target_os = "android"))]
 mod test_sendfile;
 mod test_stat;
 mod test_unistd;
 
-#[cfg(any(target_os = "linux"))]
-mod test_mq;
-
-#[cfg(any(target_os = "linux", target_os = "macos"))]
-mod test_poll;
-mod test_pty;
-
 use nixtest::assert_size_of;
 
 #[test]

test/test_pty.rs

@@ -1,8 +1,11 @@
 use std::path::Path;
 use std::os::unix::prelude::*;
+
 use nix::fcntl::{O_RDWR, open};
 use nix::pty::*;
 use nix::sys::stat;
+use nix::sys::termios::*;
+use nix::unistd::{read, write, close};
 
 /// Test equivalence of `ptsname` and `ptsname_r`
 #[test]
@@ -90,3 +93,82 @@ fn test_open_ptty_pair() {
     let slave_fd = open(Path::new(&slave_name), O_RDWR, stat::Mode::empty()).unwrap();
     assert!(slave_fd > 0);
 }
+
+#[test]
+fn test_openpty() {
+    let pty = openpty(None, None).unwrap();
+    assert!(pty.master > 0);
+    assert!(pty.slave > 0);
+
+    // Writing to one should be readable on the other one
+    let string = "foofoofoo\n";
+    let mut buf = [0u8; 16];
+    write(pty.master, string.as_bytes()).unwrap();
+    let len = read(pty.slave, &mut buf).unwrap();
+
+    assert_eq!(len, string.len());
+    assert_eq!(&buf[0..len], string.as_bytes());
+
+    // Read the echo as well
+    let echoed_string = "foofoofoo\r\n";
+    let len = read(pty.master, &mut buf).unwrap();
+    assert_eq!(len, echoed_string.len());
+    assert_eq!(&buf[0..len], echoed_string.as_bytes());
+
+    let string2 = "barbarbarbar\n";
+    let echoed_string2 = "barbarbarbar\r\n";
+    write(pty.slave, string2.as_bytes()).unwrap();
+    let len = read(pty.master, &mut buf).unwrap();
+
+    assert_eq!(len, echoed_string2.len());
+    assert_eq!(&buf[0..len], echoed_string2.as_bytes());
+
+    close(pty.master).unwrap();
+    close(pty.slave).unwrap();
+}
+
+#[test]
+fn test_openpty_with_termios() {
+    // Open one pty to get attributes for the second one
+    let mut termios = {
+        let pty = openpty(None, None).unwrap();
+        assert!(pty.master > 0);
+        assert!(pty.slave > 0);
+        let termios = tcgetattr(pty.master).unwrap();
+        close(pty.master).unwrap();
+        close(pty.slave).unwrap();
+        termios
+    };
+    termios.c_oflag &= !ONLCR;
+
+    let pty = openpty(None, &termios).unwrap();
+    // Must be valid file descriptors
+    assert!(pty.master > 0);
+    assert!(pty.slave > 0);
+
+    // Writing to one should be readable on the other one
+    let string = "foofoofoo\n";
+    let mut buf = [0u8; 16];
+    write(pty.master, string.as_bytes()).unwrap();
+    let len = read(pty.slave, &mut buf).unwrap();
+
+    assert_eq!(len, string.len());
+    assert_eq!(&buf[0..len], string.as_bytes());
+
+    // read the echo as well
+    let echoed_string = "foofoofoo\n";
+    let len = read(pty.master, &mut buf).unwrap();
+    assert_eq!(len, echoed_string.len());
+    assert_eq!(&buf[0..len], echoed_string.as_bytes());
+
+    let string2 = "barbarbarbar\n";
+    let echoed_string2 = "barbarbarbar\n";
+    write(pty.slave, string2.as_bytes()).unwrap();
+    let len = read(pty.master, &mut buf).unwrap();
+
+    assert_eq!(len, echoed_string2.len());
+    assert_eq!(&buf[0..len], echoed_string2.as_bytes());
+
+    close(pty.master).unwrap();
+    close(pty.slave).unwrap();
+}