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* grantpt * ptsname/ptsname_r * posix_openpt * unlockpt
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//! Create master and slave virtual pseudo-terminals (PTTYs) | ||
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use std::ffi::CStr; | ||
use std::os::unix::prelude::*; | ||
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use libc; | ||
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use {Error, fcntl, Result}; | ||
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#[derive(Debug)] | ||
pub struct PtyMaster(RawFd); | ||
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impl AsRawFd for PtyMaster { | ||
fn as_raw_fd(&self) -> RawFd { | ||
self.0 | ||
} | ||
} | ||
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impl IntoRawFd for PtyMaster { | ||
fn into_raw_fd(self) -> RawFd { | ||
self.0 | ||
} | ||
} | ||
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impl Drop for PtyMaster { | ||
fn drop(&mut self) { | ||
let _ = ::unistd::close(self.0); | ||
} | ||
} | ||
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/// Grant access to a slave pseudoterminal (see | ||
/// [grantpt(3)](http://man7.org/linux/man-pages/man3/grantpt.3.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().into()); | ||
} | ||
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Ok(()) | ||
} | ||
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/// Open a pseudoterminal device (see | ||
/// [posix_openpt(3)](http://man7.org/linux/man-pages/man3/posix_openpt.3.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 PTTY pair. This can be | ||
/// done as follows: | ||
/// | ||
/// ``` | ||
/// use std::path::Path; | ||
/// use nix::fcntl::{O_RDWR, open}; | ||
/// use nix::pty::*; | ||
/// use nix::sys::stat; | ||
/// | ||
/// # #[allow(dead_code)] | ||
/// # fn run() -> nix::Result<()> { | ||
/// // Open a new PTTY master | ||
/// let master_fd = posix_openpt(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 = ptsname(master_fd)?; | ||
/// | ||
/// // Try to open the slave | ||
/// # #[allow(unused_variables)] | ||
/// let slave_fd = open(Path::new(&slave_name), O_RDWR, stat::Mode::empty())?; | ||
/// # Ok(()) | ||
/// # } | ||
/// ``` | ||
#[inline] | ||
pub fn posix_openpt(flags: fcntl::OFlag) -> Result<PtyMaster> { | ||
let fd = unsafe { | ||
libc::posix_openpt(flags.bits()) | ||
}; | ||
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if fd < 0 { | ||
return Err(Error::last().into()); | ||
} | ||
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Ok(PtyMaster(fd)) | ||
} | ||
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/// 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`. Note that this function is *not* threadsafe. For that see `ptsname_r()`. | ||
/// | ||
/// This value is useful for opening the slave ptty once the master has already been opened with | ||
/// `posix_openpt()`. | ||
#[inline] | ||
pub fn ptsname(fd: &PtyMaster) -> Result<String> { | ||
let name_ptr = unsafe { libc::ptsname(fd.as_raw_fd()) }; | ||
if name_ptr.is_null() { | ||
return Err(Error::last().into()); | ||
} | ||
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let name = unsafe { | ||
CStr::from_ptr(name_ptr) | ||
}; | ||
Ok(name.to_string_lossy().into_owned()) | ||
} | ||
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/// 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 = [0 as libc::c_char; 64]; | ||
if unsafe { libc::ptsname_r(fd.as_raw_fd(), name_buf.as_mut_ptr(), name_buf.len()) } != 0 { | ||
return Err(Error::last().into()); | ||
} | ||
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let name = unsafe { | ||
CStr::from_ptr(name_buf.as_ptr()) | ||
}; | ||
Ok(name.to_string_lossy().into_owned()) | ||
} | ||
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/// Unlock a pseudoterminal master/slave pseudoterminal pair (see | ||
/// [unlockpt(3)](http://man7.org/linux/man-pages/man3/unlockpt.3.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().into()); | ||
} | ||
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Ok(()) | ||
} |
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Original file line number | Diff line number | Diff line change |
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use std::path::Path; | ||
use nix::fcntl::{O_RDWR, open}; | ||
use nix::pty::*; | ||
use nix::sys::stat; | ||
use nix::unistd::close; | ||
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/// Test equivalence of `ptsname` and `ptsname_r` | ||
#[test] | ||
#[cfg(any(target_os = "android", target_os = "linux"))] | ||
fn test_ptsname_equivalence() { | ||
// Open a new PTTY master | ||
let master_fd = posix_openpt(O_RDWR).unwrap(); | ||
assert!(master_fd.as_raw_fd() > 0); | ||
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// Get the name of the slave | ||
let slave_name = ptsname(&master_fd).unwrap(); | ||
let slave_name_r = ptsname_r(&master_fd).unwrap(); | ||
assert_eq!(slave_name, slave_name_r); | ||
} | ||
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/// Test data copying of `ptsname` | ||
#[test] | ||
#[cfg(any(target_os = "android", target_os = "linux"))] | ||
fn test_ptsname_copy() { | ||
// Open a new PTTY master | ||
let master_fd = posix_openpt(O_RDWR).unwrap(); | ||
assert!(master_fd.as_raw_fd() > 0); | ||
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// Get the name of the slave | ||
let slave_name1 = ptsname(&master_fd).unwrap(); | ||
let slave_name2 = ptsname(&master_fd).unwrap(); | ||
assert!(slave_name1 == slave_name2); | ||
assert!(slave_name1.as_ptr() != slave_name2.as_ptr()); | ||
} | ||
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/// Test data copying of `ptsname_r` | ||
#[test] | ||
#[cfg(any(target_os = "android", target_os = "linux"))] | ||
fn test_ptsname_r_copy() { | ||
// Open a new PTTY master | ||
let master_fd = posix_openpt(O_RDWR).unwrap(); | ||
assert!(master_fd.as_raw_fd() > 0); | ||
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// Get the name of the slave | ||
let slave_name1 = ptsname_r(&master_fd).unwrap(); | ||
let slave_name2 = ptsname_r(&master_fd).unwrap(); | ||
assert!(slave_name1 == slave_name2); | ||
assert!(slave_name1.as_ptr() != slave_name2.as_ptr()); | ||
} | ||
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/// Test that `ptsname` returns different names for different devices | ||
#[test] | ||
#[cfg(any(target_os = "android", target_os = "linux"))] | ||
fn test_ptsname_unique() { | ||
// Open a new PTTY master | ||
let master1_fd = posix_openpt(O_RDWR).unwrap(); | ||
assert!(master1_fd.as_raw_fd() > 0); | ||
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// Open a second PTTY master | ||
let master2_fd = posix_openpt(O_RDWR).unwrap(); | ||
assert!(master2_fd.as_raw_fd() > 0); | ||
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// Get the name of the slave | ||
let slave_name1 = ptsname(&master1_fd).unwrap(); | ||
let slave_name2 = ptsname(&master2_fd).unwrap(); | ||
assert!(slave_name1 != slave_name2); | ||
} | ||
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/// Test opening a master/slave PTTY pair | ||
/// | ||
/// This is a single larger test because much of these functions aren't useful by themselves. So for | ||
/// this test we perform the basic act of getting a file handle for a connect master/slave PTTY | ||
/// pair. | ||
#[test] | ||
fn test_open_ptty_pair() { | ||
// Open a new PTTY master | ||
let master_fd = posix_openpt(O_RDWR).unwrap(); | ||
assert!(master_fd.as_raw_fd() > 0); | ||
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// Allow a slave to be generated for it | ||
grantpt(&master_fd).unwrap(); | ||
unlockpt(&master_fd).unwrap(); | ||
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// Get the name of the slave | ||
let slave_name = ptsname(&master_fd).unwrap(); | ||
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// Open the slave device | ||
let slave_fd = open(Path::new(&slave_name), O_RDWR, stat::Mode::empty()).unwrap(); | ||
assert!(slave_fd > 0); | ||
} |