comm-central/third_party/rust/nix/src/unistd.rs

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//! Safe wrappers around functions found in libc "unistd.h" header
use crate::errno::Errno;
#[cfg(any(
all(feature = "fs", not(target_os = "redox")),
all(feature = "process", linux_android)
))]
use crate::fcntl::at_rawfd;
#[cfg(not(target_os = "redox"))]
#[cfg(feature = "fs")]
use crate::fcntl::AtFlags;
#[cfg(feature = "fs")]
#[cfg(any(
linux_android,
freebsdlike,
solarish,
netbsdlike,
target_os = "emscripten",
target_os = "fuchsia",
target_os = "hurd",
target_os = "redox",
))]
use crate::fcntl::OFlag;
#[cfg(all(feature = "fs", bsd))]
use crate::sys::stat::FileFlag;
#[cfg(feature = "fs")]
use crate::sys::stat::Mode;
use crate::{Error, NixPath, Result};
#[cfg(not(target_os = "redox"))]
use cfg_if::cfg_if;
use libc::{
c_char, c_int, c_long, c_uint, gid_t, mode_t, off_t, pid_t, size_t, uid_t,
};
use std::convert::Infallible;
#[cfg(not(target_os = "redox"))]
use std::ffi::CString;
use std::ffi::{CStr, OsStr, OsString};
use std::os::unix::ffi::{OsStrExt, OsStringExt};
use std::os::unix::io::{AsFd, AsRawFd, OwnedFd, RawFd};
use std::path::PathBuf;
use std::{fmt, mem, ptr};
feature! {
#![feature = "fs"]
#[cfg(linux_android)]
pub use self::pivot_root::*;
}
#[cfg(any(freebsdlike, linux_android, target_os = "openbsd"))]
pub use self::setres::*;
#[cfg(any(freebsdlike, linux_android, target_os = "openbsd"))]
pub use self::getres::*;
feature! {
#![feature = "user"]
/// User identifier
///
/// Newtype pattern around `uid_t` (which is just alias). It prevents bugs caused by accidentally
/// passing wrong value.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub struct Uid(uid_t);
impl Uid {
/// Creates `Uid` from raw `uid_t`.
pub const fn from_raw(uid: uid_t) -> Self {
Uid(uid)
}
/// Returns Uid of calling process. This is practically a more Rusty alias for `getuid`.
#[doc(alias("getuid"))]
pub fn current() -> Self {
getuid()
}
/// Returns effective Uid of calling process. This is practically a more Rusty alias for `geteuid`.
#[doc(alias("geteuid"))]
pub fn effective() -> Self {
geteuid()
}
/// Returns true if the `Uid` represents privileged user - root. (If it equals zero.)
pub const fn is_root(self) -> bool {
self.0 == ROOT.0
}
/// Get the raw `uid_t` wrapped by `self`.
pub const fn as_raw(self) -> uid_t {
self.0
}
}
impl From<Uid> for uid_t {
fn from(uid: Uid) -> Self {
uid.0
}
}
impl From<uid_t> for Uid {
fn from(uid: uid_t) -> Self {
Uid(uid)
}
}
impl fmt::Display for Uid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
/// Constant for UID = 0
pub const ROOT: Uid = Uid(0);
/// Group identifier
///
/// Newtype pattern around `gid_t` (which is just alias). It prevents bugs caused by accidentally
/// passing wrong value.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub struct Gid(gid_t);
impl Gid {
/// Creates `Gid` from raw `gid_t`.
pub const fn from_raw(gid: gid_t) -> Self {
Gid(gid)
}
/// Returns Gid of calling process. This is practically a more Rusty alias for `getgid`.
#[doc(alias("getgid"))]
pub fn current() -> Self {
getgid()
}
/// Returns effective Gid of calling process. This is practically a more Rusty alias for `getegid`.
#[doc(alias("getegid"))]
pub fn effective() -> Self {
getegid()
}
/// Get the raw `gid_t` wrapped by `self`.
pub const fn as_raw(self) -> gid_t {
self.0
}
}
impl From<Gid> for gid_t {
fn from(gid: Gid) -> Self {
gid.0
}
}
impl From<gid_t> for Gid {
fn from(gid: gid_t) -> Self {
Gid(gid)
}
}
impl fmt::Display for Gid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
}
feature! {
#![feature = "process"]
/// Process identifier
///
/// Newtype pattern around `pid_t` (which is just alias). It prevents bugs caused by accidentally
/// passing wrong value.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct Pid(pid_t);
impl Pid {
/// Creates `Pid` from raw `pid_t`.
pub const fn from_raw(pid: pid_t) -> Self {
Pid(pid)
}
/// Returns PID of calling process
#[doc(alias("getpid"))]
pub fn this() -> Self {
getpid()
}
/// Returns PID of parent of calling process
#[doc(alias("getppid"))]
pub fn parent() -> Self {
getppid()
}
/// Get the raw `pid_t` wrapped by `self`.
pub const fn as_raw(self) -> pid_t {
self.0
}
}
impl From<Pid> for pid_t {
fn from(pid: Pid) -> Self {
pid.0
}
}
impl fmt::Display for Pid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
/// Represents the successful result of calling `fork`
///
/// When `fork` is called, the process continues execution in the parent process
/// and in the new child. This return type can be examined to determine whether
/// you are now executing in the parent process or in the child.
#[derive(Clone, Copy, Debug)]
pub enum ForkResult {
/// This is the parent process of the fork.
Parent {
/// The PID of the fork's child process
child: Pid
},
/// This is the child process of the fork.
Child,
}
impl ForkResult {
/// Return `true` if this is the child process of the `fork()`
#[inline]
pub fn is_child(self) -> bool {
matches!(self, ForkResult::Child)
}
/// Returns `true` if this is the parent process of the `fork()`
#[inline]
pub fn is_parent(self) -> bool {
!self.is_child()
}
}
/// Create a new child process duplicating the parent process ([see
///
/// After successfully calling the fork system call, a second process will
/// be created which is identical to the original except for the pid and the
/// return value of this function. As an example:
///
/// ```
/// use nix::{sys::wait::waitpid,unistd::{fork, ForkResult, write}};
///
/// match unsafe{fork()} {
/// Ok(ForkResult::Parent { child, .. }) => {
/// println!("Continuing execution in parent process, new child has pid: {}", child);
/// waitpid(child, None).unwrap();
/// }
/// Ok(ForkResult::Child) => {
/// // Unsafe to use `println!` (or `unwrap`) here. See Safety.
/// write(std::io::stdout(), "I'm a new child process\n".as_bytes()).ok();
/// unsafe { libc::_exit(0) };
/// }
/// Err(_) => println!("Fork failed"),
/// }
/// ```
///
/// This will print something like the following (order nondeterministic). The
/// thing to note is that you end up with two processes continuing execution
/// immediately after the fork call but with different match arms.
///
/// ```text
/// Continuing execution in parent process, new child has pid: 1234
/// I'm a new child process
/// ```
///
/// # Safety
///
/// In a multithreaded program, only [async-signal-safe] functions like `pause`
/// and `_exit` may be called by the child (the parent isn't restricted). Note
/// that memory allocation may **not** be async-signal-safe and thus must be
/// prevented.
///
/// Those functions are only a small subset of your operating system's API, so
/// special care must be taken to only invoke code you can control and audit.
///
#[inline]
pub unsafe fn fork() -> Result<ForkResult> {
use self::ForkResult::*;
let res = unsafe { libc::fork() };
Errno::result(res).map(|res| match res {
0 => Child,
res => Parent { child: Pid(res) },
})
}
/// Get the pid of this process (see
///
/// Since you are running code, there is always a pid to return, so there
/// is no error case that needs to be handled.
#[inline]
pub fn getpid() -> Pid {
Pid(unsafe { libc::getpid() })
}
/// Get the pid of this processes' parent (see
///
/// There is always a parent pid to return, so there is no error case that needs
/// to be handled.
#[inline]
pub fn getppid() -> Pid {
Pid(unsafe { libc::getppid() }) // no error handling, according to man page: "These functions are always successful."
}
/// Set a process group ID (see
///
/// Set the process group id (PGID) of a particular process. If a pid of zero
/// is specified, then the pid of the calling process is used. Process groups
/// may be used to group together a set of processes in order for the OS to
/// apply some operations across the group.
///
/// `setsid()` may be used to create a new process group.
#[inline]
pub fn setpgid(pid: Pid, pgid: Pid) -> Result<()> {
let res = unsafe { libc::setpgid(pid.into(), pgid.into()) };
Errno::result(res).map(drop)
}
/// Get process group
///
#[inline]
pub fn getpgid(pid: Option<Pid>) -> Result<Pid> {
let res = unsafe { libc::getpgid(pid.unwrap_or(Pid(0)).into()) };
Errno::result(res).map(Pid)
}
/// Create new session and set process group id (see
#[inline]
pub fn setsid() -> Result<Pid> {
Errno::result(unsafe { libc::setsid() }).map(Pid)
}
/// Get the process group ID of a session leader
///
/// Obtain the process group ID of the process that is the session leader of the process specified
/// by pid. If pid is zero, it specifies the calling process.
#[inline]
#[cfg(not(target_os = "redox"))]
pub fn getsid(pid: Option<Pid>) -> Result<Pid> {
let res = unsafe { libc::getsid(pid.unwrap_or(Pid(0)).into()) };
Errno::result(res).map(Pid)
}
}
feature! {
#![all(feature = "process", feature = "term")]
/// Get the terminal foreground process group (see
///
/// Get the group process id (GPID) of the foreground process group on the
/// terminal associated to file descriptor (FD).
#[inline]
pub fn tcgetpgrp<F: AsFd>(fd: F) -> Result<Pid> {
let res = unsafe { libc::tcgetpgrp(fd.as_fd().as_raw_fd()) };
Errno::result(res).map(Pid)
}
/// Set the terminal foreground process group (see
///
/// Get the group process id (PGID) to the foreground process group on the
/// terminal associated to file descriptor (FD).
#[inline]
pub fn tcsetpgrp<F: AsFd>(fd: F, pgrp: Pid) -> Result<()> {
let res = unsafe { libc::tcsetpgrp(fd.as_fd().as_raw_fd(), pgrp.into()) };
Errno::result(res).map(drop)
}
}
feature! {
#![feature = "process"]
/// Get the group id of the calling process (see
///
/// Get the process group id (PGID) of the calling process.
/// According to the man page it is always successful.
#[inline]
pub fn getpgrp() -> Pid {
Pid(unsafe { libc::getpgrp() })
}
/// Get the caller's thread ID (see
///
/// This function is only available on Linux based systems. In a single
/// threaded process, the main thread will have the same ID as the process. In
/// a multithreaded process, each thread will have a unique thread id but the
/// same process ID.
///
/// No error handling is required as a thread id should always exist for any
/// process, even if threads are not being used.
#[cfg(linux_android)]
#[inline]
pub fn gettid() -> Pid {
Pid(unsafe { libc::syscall(libc::SYS_gettid) as pid_t })
}
}
feature! {
#![feature = "fs"]
/// Create a copy of the specified file descriptor (see
///
/// The new file descriptor will have a new index but refer to the same
/// resource as the old file descriptor and the old and new file descriptors may
/// be used interchangeably. The new and old file descriptor share the same
/// underlying resource, offset, and file status flags. The actual index used
/// for the file descriptor will be the lowest fd index that is available.
///
/// The two file descriptors do not share file descriptor flags (e.g. `OFlag::FD_CLOEXEC`).
#[inline]
pub fn dup(oldfd: RawFd) -> Result<RawFd> {
let res = unsafe { libc::dup(oldfd) };
Errno::result(res)
}
/// Create a copy of the specified file descriptor using the specified fd (see
///
/// This function behaves similar to `dup()` except that it will try to use the
/// specified fd instead of allocating a new one. See the man pages for more
/// detail on the exact behavior of this function.
#[inline]
pub fn dup2(oldfd: RawFd, newfd: RawFd) -> Result<RawFd> {
let res = unsafe { libc::dup2(oldfd, newfd) };
Errno::result(res)
}
/// Create a new copy of the specified file descriptor using the specified fd
/// and flags (see [`dup(2)`](https://man7.org/linux/man-pages/man2/dup.2.html)).
///
/// This function behaves similar to `dup2()` but allows for flags to be
/// specified.
#[cfg(any(
netbsdlike,
solarish,
target_os = "freebsd",
target_os = "fuchsia",
target_os = "hurd",
target_os = "linux"
))]
pub fn dup3(oldfd: RawFd, newfd: RawFd, flags: OFlag) -> Result<RawFd> {
let res = unsafe { libc::dup3(oldfd, newfd, flags.bits()) };
Errno::result(res)
}
/// Change the current working directory of the calling process (see
///
/// This function may fail in a number of different scenarios. See the man
/// pages for additional details on possible failure cases.
#[inline]
pub fn chdir<P: ?Sized + NixPath>(path: &P) -> Result<()> {
let res =
path.with_nix_path(|cstr| unsafe { libc::chdir(cstr.as_ptr()) })?;
Errno::result(res).map(drop)
}
/// Change the current working directory of the process to the one
/// given as an open file descriptor (see
///
/// This function may fail in a number of different scenarios. See the man
/// pages for additional details on possible failure cases.
#[inline]
#[cfg(not(target_os = "fuchsia"))]
pub fn fchdir(dirfd: RawFd) -> Result<()> {
let res = unsafe { libc::fchdir(dirfd) };
Errno::result(res).map(drop)
}
/// Creates new directory `path` with access rights `mode`. (see [mkdir(2)](https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdir.html))
///
/// # Errors
///
/// There are several situations where mkdir might fail:
///
/// - current user has insufficient rights in the parent directory
/// - the path already exists
/// - the path name is too long (longer than `PATH_MAX`, usually 4096 on linux, 1024 on OS X)
///
/// # Example
///
/// ```rust
/// use nix::unistd;
/// use nix::sys::stat;
/// use tempfile::tempdir;
///
/// let tmp_dir1 = tempdir().unwrap();
/// let tmp_dir2 = tmp_dir1.path().join("new_dir");
///
/// // create new directory and give read, write and execute rights to the owner
/// match unistd::mkdir(&tmp_dir2, stat::Mode::S_IRWXU) {
/// Ok(_) => println!("created {:?}", tmp_dir2),
/// Err(err) => println!("Error creating directory: {}", err),
/// }
/// ```
#[inline]
pub fn mkdir<P: ?Sized + NixPath>(path: &P, mode: Mode) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::mkdir(cstr.as_ptr(), mode.bits() as mode_t)
})?;
Errno::result(res).map(drop)
}
/// Creates new fifo special file (named pipe) with path `path` and access rights `mode`.
///
/// # Errors
///
/// There are several situations where mkfifo might fail:
///
/// - current user has insufficient rights in the parent directory
/// - the path already exists
/// - the path name is too long (longer than `PATH_MAX`, usually 4096 on linux, 1024 on OS X)
///
/// For a full list consult
///
/// # Example
///
/// ```rust
/// use nix::unistd;
/// use nix::sys::stat;
/// use tempfile::tempdir;
///
/// let tmp_dir = tempdir().unwrap();
/// let fifo_path = tmp_dir.path().join("foo.pipe");
///
/// // create new fifo and give read, write and execute rights to the owner
/// match unistd::mkfifo(&fifo_path, stat::Mode::S_IRWXU) {
/// Ok(_) => println!("created {:?}", fifo_path),
/// Err(err) => println!("Error creating fifo: {}", err),
/// }
/// ```
#[inline]
#[cfg(not(target_os = "redox"))] // RedoxFS does not support fifo yet
pub fn mkfifo<P: ?Sized + NixPath>(path: &P, mode: Mode) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::mkfifo(cstr.as_ptr(), mode.bits() as mode_t)
})?;
Errno::result(res).map(drop)
}
/// Creates new fifo special file (named pipe) with path `path` and access rights `mode`.
///
/// If `dirfd` has a value, then `path` is relative to directory associated with the file descriptor.
///
/// If `dirfd` is `None`, then `path` is relative to the current working directory.
///
/// # References
///
// mkfifoat is not implemented in OSX or android
#[inline]
#[cfg(not(any(
apple_targets,
target_os = "haiku",
target_os = "android",
target_os = "redox"
)))]
pub fn mkfifoat<P: ?Sized + NixPath>(
dirfd: Option<RawFd>,
path: &P,
mode: Mode,
) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::mkfifoat(at_rawfd(dirfd), cstr.as_ptr(), mode.bits() as mode_t)
})?;
Errno::result(res).map(drop)
}
/// Creates a symbolic link at `path2` which points to `path1`.
///
/// If `dirfd` has a value, then `path2` is relative to directory associated
/// with the file descriptor.
///
/// If `dirfd` is `None`, then `path2` is relative to the current working
/// directory. This is identical to `libc::symlink(path1, path2)`.
///
#[cfg(not(target_os = "redox"))]
pub fn symlinkat<P1: ?Sized + NixPath, P2: ?Sized + NixPath>(
path1: &P1,
dirfd: Option<RawFd>,
path2: &P2,
) -> Result<()> {
let res = path1.with_nix_path(|path1| {
path2.with_nix_path(|path2| unsafe {
libc::symlinkat(
path1.as_ptr(),
dirfd.unwrap_or(libc::AT_FDCWD),
path2.as_ptr(),
)
})
})??;
Errno::result(res).map(drop)
}
}
// Double the buffer capacity up to limit. In case it already has
// reached the limit, return Errno::ERANGE.
#[cfg(any(feature = "fs", feature = "user"))]
fn reserve_double_buffer_size<T>(buf: &mut Vec<T>, limit: usize) -> Result<()> {
use std::cmp::min;
if buf.capacity() >= limit {
return Err(Errno::ERANGE);
}
let capacity = min(buf.capacity() * 2, limit);
buf.reserve(capacity);
Ok(())
}
feature! {
#![feature = "fs"]
/// Returns the current directory as a `PathBuf`
///
/// Err is returned if the current user doesn't have the permission to read or search a component
/// of the current path.
///
/// # Example
///
/// ```rust
/// use nix::unistd;
///
/// // assume that we are allowed to get current directory
/// let dir = unistd::getcwd().unwrap();
/// println!("The current directory is {:?}", dir);
/// ```
#[inline]
pub fn getcwd() -> Result<PathBuf> {
let mut buf = Vec::<u8>::with_capacity(512);
loop {
unsafe {
let ptr = buf.as_mut_ptr().cast();
// The buffer must be large enough to store the absolute pathname plus
// a terminating null byte, or else null is returned.
// To safely handle this we start with a reasonable size (512 bytes)
// and double the buffer size upon every error
if !libc::getcwd(ptr, buf.capacity()).is_null() {
let len = CStr::from_ptr(buf.as_ptr().cast())
.to_bytes()
.len();
buf.set_len(len);
buf.shrink_to_fit();
return Ok(PathBuf::from(OsString::from_vec(buf)));
} else {
let error = Errno::last();
// ERANGE means buffer was too small to store directory name
if error != Errno::ERANGE {
return Err(error);
}
}
#[cfg(not(target_os = "hurd"))]
const PATH_MAX: usize = libc::PATH_MAX as usize;
#[cfg(target_os = "hurd")]
const PATH_MAX: usize = 1024; // Hurd does not define a hard limit, so try a guess first
// Trigger the internal buffer resizing logic.
reserve_double_buffer_size(&mut buf, PATH_MAX)?;
}
}
}
}
feature! {
#![all(feature = "user", feature = "fs")]
/// Computes the raw UID and GID values to pass to a `*chown` call.
// The cast is not unnecessary on all platforms.
#[allow(clippy::unnecessary_cast)]
fn chown_raw_ids(owner: Option<Uid>, group: Option<Gid>) -> (uid_t, gid_t) {
// According to the POSIX specification, -1 is used to indicate that owner and group
// are not to be changed. Since uid_t and gid_t are unsigned types, we have to wrap
// around to get -1.
let uid = owner
.map(Into::into)
.unwrap_or_else(|| (0 as uid_t).wrapping_sub(1));
let gid = group
.map(Into::into)
.unwrap_or_else(|| (0 as gid_t).wrapping_sub(1));
(uid, gid)
}
/// Change the ownership of the file at `path` to be owned by the specified
/// `owner` (user) and `group` (see
///
/// The owner/group for the provided path name will not be modified if `None` is
/// provided for that argument. Ownership change will be attempted for the path
/// only if `Some` owner/group is provided.
#[inline]
pub fn chown<P: ?Sized + NixPath>(
path: &P,
owner: Option<Uid>,
group: Option<Gid>,
) -> Result<()> {
let res = path.with_nix_path(|cstr| {
let (uid, gid) = chown_raw_ids(owner, group);
unsafe { libc::chown(cstr.as_ptr(), uid, gid) }
})?;
Errno::result(res).map(drop)
}
/// Change the ownership of the file referred to by the open file descriptor `fd` to be owned by
/// the specified `owner` (user) and `group` (see
///
/// The owner/group for the provided file will not be modified if `None` is
/// provided for that argument. Ownership change will be attempted for the path
/// only if `Some` owner/group is provided.
#[inline]
pub fn fchown(fd: RawFd, owner: Option<Uid>, group: Option<Gid>) -> Result<()> {
let (uid, gid) = chown_raw_ids(owner, group);
let res = unsafe { libc::fchown(fd, uid, gid) };
Errno::result(res).map(drop)
}
// Just a wrapper around `AtFlags` so that we can help our users migrate.
#[allow(missing_docs)]
#[cfg(not(target_os = "redox"))]
pub type FchownatFlags = AtFlags;
#[allow(missing_docs)]
#[cfg(not(target_os = "redox"))]
impl FchownatFlags {
#[deprecated(since = "0.28.0", note = "The variant is deprecated, please use `AtFlags` instead")]
#[allow(non_upper_case_globals)]
pub const FollowSymlink: FchownatFlags = FchownatFlags::empty();
#[deprecated(since = "0.28.0", note = "The variant is deprecated, please use `AtFlags` instead")]
#[allow(non_upper_case_globals)]
pub const NoFollowSymlink: FchownatFlags = FchownatFlags::AT_SYMLINK_NOFOLLOW;
}
/// Change the ownership of the file at `path` to be owned by the specified
/// `owner` (user) and `group`.
///
/// The owner/group for the provided path name will not be modified if `None` is
/// provided for that argument. Ownership change will be attempted for the path
/// only if `Some` owner/group is provided.
///
/// The file to be changed is determined relative to the directory associated
/// with the file descriptor `dirfd` or the current working directory
/// if `dirfd` is `None`.
///
/// If `flag` is `AtFlags::AT_SYMLINK_NOFOLLOW` and `path` names a symbolic link,
/// then the mode of the symbolic link is changed.
///
/// `fchownat(None, path, owner, group, AtFlags::AT_SYMLINK_NOFOLLOW)` is identical to
/// a call `libc::lchown(path, owner, group)`. That's why `lchown` is unimplemented in
/// the `nix` crate.
///
/// # References
///
#[cfg(not(target_os = "redox"))]
pub fn fchownat<P: ?Sized + NixPath>(
dirfd: Option<RawFd>,
path: &P,
owner: Option<Uid>,
group: Option<Gid>,
flag: AtFlags,
) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
let (uid, gid) = chown_raw_ids(owner, group);
libc::fchownat(
at_rawfd(dirfd),
cstr.as_ptr(),
uid,
gid,
flag.bits()
)
})?;
Errno::result(res).map(drop)
}
}
feature! {
#![feature = "process"]
fn to_exec_array<S: AsRef<CStr>>(args: &[S]) -> Vec<*const c_char> {
use std::iter::once;
args.iter()
.map(|s| s.as_ref().as_ptr())
.chain(once(ptr::null()))
.collect()
}
/// Replace the current process image with a new one (see
///
/// See the `::nix::unistd::execve` system call for additional details. `execv`
/// performs the same action but does not allow for customization of the
/// environment for the new process.
#[inline]
pub fn execv<S: AsRef<CStr>>(path: &CStr, argv: &[S]) -> Result<Infallible> {
let args_p = to_exec_array(argv);
unsafe { libc::execv(path.as_ptr(), args_p.as_ptr()) };
Err(Errno::last())
}
/// Replace the current process image with a new one (see
///
/// The execve system call allows for another process to be "called" which will
/// replace the current process image. That is, this process becomes the new
/// command that is run. On success, this function will not return. Instead,
/// the new program will run until it exits.
///
/// `::nix::unistd::execv` and `::nix::unistd::execve` take as arguments a slice
/// of `::std::ffi::CString`s for `args` and `env` (for `execve`). Each element
/// in the `args` list is an argument to the new process. Each element in the
/// `env` list should be a string in the form "key=value".
#[inline]
pub fn execve<SA: AsRef<CStr>, SE: AsRef<CStr>>(
path: &CStr,
args: &[SA],
env: &[SE],
) -> Result<Infallible> {
let args_p = to_exec_array(args);
let env_p = to_exec_array(env);
unsafe { libc::execve(path.as_ptr(), args_p.as_ptr(), env_p.as_ptr()) };
Err(Errno::last())
}
/// Replace the current process image with a new one and replicate shell `PATH`
/// searching behavior (see
///
/// See `::nix::unistd::execve` for additional details. `execvp` behaves the
/// same as execv except that it will examine the `PATH` environment variables
/// for file names not specified with a leading slash. For example, `execv`
/// would not work if "bash" was specified for the path argument, but `execvp`
/// would assuming that a bash executable was on the system `PATH`.
#[inline]
pub fn execvp<S: AsRef<CStr>>(
filename: &CStr,
args: &[S],
) -> Result<Infallible> {
let args_p = to_exec_array(args);
unsafe { libc::execvp(filename.as_ptr(), args_p.as_ptr()) };
Err(Errno::last())
}
/// Replace the current process image with a new one and replicate shell `PATH`
/// searching behavior (see
///
/// This functions like a combination of `execvp(2)` and `execve(2)` to pass an
/// environment and have a search path. See these two for additional
/// information.
#[cfg(any(target_os = "haiku", target_os = "hurd", target_os = "linux", target_os = "openbsd"))]
pub fn execvpe<SA: AsRef<CStr>, SE: AsRef<CStr>>(
filename: &CStr,
args: &[SA],
env: &[SE],
) -> Result<Infallible> {
let args_p = to_exec_array(args);
let env_p = to_exec_array(env);
unsafe {
libc::execvpe(filename.as_ptr(), args_p.as_ptr(), env_p.as_ptr())
};
Err(Errno::last())
}
/// Replace the current process image with a new one (see
///
/// The `fexecve` function allows for another process to be "called" which will
/// replace the current process image. That is, this process becomes the new
/// command that is run. On success, this function will not return. Instead,
/// the new program will run until it exits.
///
/// This function is similar to `execve`, except that the program to be executed
/// is referenced as a file descriptor instead of a path.
#[cfg(any(linux_android, freebsdlike, target_os = "hurd"))]
#[inline]
pub fn fexecve<SA: AsRef<CStr>, SE: AsRef<CStr>>(
fd: RawFd,
args: &[SA],
env: &[SE],
) -> Result<Infallible> {
let args_p = to_exec_array(args);
let env_p = to_exec_array(env);
unsafe { libc::fexecve(fd, args_p.as_ptr(), env_p.as_ptr()) };
Err(Errno::last())
}
/// Execute program relative to a directory file descriptor (see
///
/// The `execveat` function allows for another process to be "called" which will
/// replace the current process image. That is, this process becomes the new
/// command that is run. On success, this function will not return. Instead,
/// the new program will run until it exits.
///
/// This function is similar to `execve`, except that the program to be executed
/// is referenced as a file descriptor to the base directory plus a path.
#[cfg(linux_android)]
#[inline]
pub fn execveat<SA: AsRef<CStr>, SE: AsRef<CStr>>(
dirfd: Option<RawFd>,
pathname: &CStr,
args: &[SA],
env: &[SE],
flags: super::fcntl::AtFlags,
) -> Result<Infallible> {
let dirfd = at_rawfd(dirfd);
let args_p = to_exec_array(args);
let env_p = to_exec_array(env);
unsafe {
libc::syscall(
libc::SYS_execveat,
dirfd,
pathname.as_ptr(),
args_p.as_ptr(),
env_p.as_ptr(),
flags,
);
};
Err(Errno::last())
}
/// Daemonize this process by detaching from the controlling terminal (see
///
/// When a process is launched it is typically associated with a parent and it,
/// in turn, by its controlling terminal/process. In order for a process to run
/// in the "background" it must daemonize itself by detaching itself. Under
/// posix, this is done by doing the following:
///
/// 1. Parent process (this one) forks
/// 2. Parent process exits
/// 3. Child process continues to run.
///
/// `nochdir`:
///
/// * `nochdir = true`: The current working directory after daemonizing will
/// be the current working directory.
/// * `nochdir = false`: The current working directory after daemonizing will
/// be the root direcory, `/`.
///
/// `noclose`:
///
/// * `noclose = true`: The process' current stdin, stdout, and stderr file
/// descriptors will remain identical after daemonizing.
/// * `noclose = false`: The process' stdin, stdout, and stderr will point to
/// `/dev/null` after daemonizing.
#[cfg(any(
linux_android,
freebsdlike,
solarish,
netbsdlike
))]
pub fn daemon(nochdir: bool, noclose: bool) -> Result<()> {
let res = unsafe { libc::daemon(nochdir as c_int, noclose as c_int) };
Errno::result(res).map(drop)
}
}
feature! {
#![feature = "hostname"]
/// Set the system host name (see
///
/// Given a name, attempt to update the system host name to the given string.
/// On some systems, the host name is limited to as few as 64 bytes. An error
/// will be returned if the name is not valid or the current process does not
/// have permissions to update the host name.
#[cfg(not(target_os = "redox"))]
pub fn sethostname<S: AsRef<OsStr>>(name: S) -> Result<()> {
// Handle some differences in type of the len arg across platforms.
cfg_if! {
if #[cfg(any(freebsdlike,
solarish,
apple_targets,
target_os = "aix"))] {
type sethostname_len_t = c_int;
} else {
type sethostname_len_t = size_t;
}
}
let ptr = name.as_ref().as_bytes().as_ptr().cast();
let len = name.as_ref().len() as sethostname_len_t;
let res = unsafe { libc::sethostname(ptr, len) };
Errno::result(res).map(drop)
}
/// Get the host name and store it in an internally allocated buffer, returning an
/// `OsString` on success (see
///
/// This function call attempts to get the host name for the running system and
/// store it in an internal buffer, returning it as an `OsString` if successful.
///
/// ```no_run
/// use nix::unistd;
///
/// let hostname = unistd::gethostname().expect("Failed getting hostname");
/// let hostname = hostname.into_string().expect("Hostname wasn't valid UTF-8");
/// println!("Hostname: {}", hostname);
/// ```
pub fn gethostname() -> Result<OsString> {
// The capacity is the max length of a hostname plus the NUL terminator.
let mut buffer: Vec<u8> = Vec::with_capacity(256);
let ptr = buffer.as_mut_ptr().cast();
let len = buffer.capacity() as size_t;
let res = unsafe { libc::gethostname(ptr, len) };
Errno::result(res).map(|_| {
unsafe {
buffer.as_mut_ptr().wrapping_add(len - 1).write(0); // ensure always null-terminated
let len = CStr::from_ptr(buffer.as_ptr().cast()).len();
buffer.set_len(len);
}
OsString::from_vec(buffer)
})
}
}
/// Close a raw file descriptor
///
/// Be aware that many Rust types implicitly close-on-drop, including
/// `std::fs::File`. Explicitly closing them with this method too can result in
/// a double-close condition, which can cause confusing `EBADF` errors in
/// seemingly unrelated code. Caveat programmer. See also
///
/// # Examples
///
/// ```no_run
/// use std::os::unix::io::AsRawFd;
/// use nix::unistd::close;
///
/// let f = tempfile::tempfile().unwrap();
/// close(f.as_raw_fd()).unwrap(); // Bad! f will also close on drop!
/// ```
///
/// ```rust
/// use std::os::unix::io::IntoRawFd;
/// use nix::unistd::close;
///
/// let f = tempfile::tempfile().unwrap();
/// close(f.into_raw_fd()).unwrap(); // Good. into_raw_fd consumes f
/// ```
pub fn close(fd: RawFd) -> Result<()> {
let res = unsafe { libc::close(fd) };
Errno::result(res).map(drop)
}
/// Read from a raw file descriptor.
///
pub fn read(fd: RawFd, buf: &mut [u8]) -> Result<usize> {
let res =
unsafe { libc::read(fd, buf.as_mut_ptr().cast(), buf.len() as size_t) };
Errno::result(res).map(|r| r as usize)
}
/// Write to a raw file descriptor.
///
pub fn write<Fd: AsFd>(fd: Fd, buf: &[u8]) -> Result<usize> {
let res = unsafe {
libc::write(
fd.as_fd().as_raw_fd(),
buf.as_ptr().cast(),
buf.len() as size_t,
)
};
Errno::result(res).map(|r| r as usize)
}
feature! {
#![feature = "fs"]
/// Directive that tells [`lseek`] and [`lseek64`] what the offset is relative to.
///
/// [`lseek`]: ./fn.lseek.html
/// [`lseek64`]: ./fn.lseek64.html
#[repr(i32)]
#[derive(Clone, Copy, Debug)]
pub enum Whence {
/// Specify an offset relative to the start of the file.
SeekSet = libc::SEEK_SET,
/// Specify an offset relative to the current file location.
SeekCur = libc::SEEK_CUR,
/// Specify an offset relative to the end of the file.
SeekEnd = libc::SEEK_END,
/// Specify an offset relative to the next location in the file greater than or
/// equal to offset that contains some data. If offset points to
/// some data, then the file offset is set to offset.
#[cfg(any(
freebsdlike,
solarish,
target_os = "linux",
))]
SeekData = libc::SEEK_DATA,
/// Specify an offset relative to the next hole in the file greater than
/// or equal to offset. If offset points into the middle of a hole, then
/// the file offset should be set to offset. If there is no hole past offset,
/// then the file offset should be adjusted to the end of the file (i.e., there
/// is an implicit hole at the end of any file).
#[cfg(any(
freebsdlike,
solarish,
target_os = "linux",
))]
SeekHole = libc::SEEK_HOLE,
}
/// Move the read/write file offset.
///
pub fn lseek(fd: RawFd, offset: off_t, whence: Whence) -> Result<off_t> {
let res = unsafe { libc::lseek(fd, offset, whence as i32) };
Errno::result(res).map(|r| r as off_t)
}
/// Move the read/write file offset.
///
/// Unlike [`lseek`], it takes a 64-bit argument even on platforms where [`libc::off_t`] is
/// 32 bits.
#[cfg(linux_android)]
pub fn lseek64(
fd: RawFd,
offset: libc::off64_t,
whence: Whence,
) -> Result<libc::off64_t> {
let res = unsafe { libc::lseek64(fd, offset, whence as i32) };
Errno::result(res).map(|r| r as libc::off64_t)
}
}
/// Create an interprocess channel.
///
pub fn pipe() -> std::result::Result<(OwnedFd, OwnedFd), Error> {
let mut fds = mem::MaybeUninit::<[OwnedFd; 2]>::uninit();
let res = unsafe { libc::pipe(fds.as_mut_ptr().cast()) };
Error::result(res)?;
let [read, write] = unsafe { fds.assume_init() };
Ok((read, write))
}
feature! {
#![feature = "fs"]
/// Like `pipe`, but allows setting certain file descriptor flags.
///
/// The following flags are supported, and will be set atomically as the pipe is
/// created:
///
/// - `O_CLOEXEC`: Set the close-on-exec flag for the new file descriptors.
#[cfg_attr(
target_os = "linux",
doc = "- `O_DIRECT`: Create a pipe that performs I/O in \"packet\" mode."
)]
#[cfg_attr(
target_os = "netbsd",
doc = "- `O_NOSIGPIPE`: Return `EPIPE` instead of raising `SIGPIPE`."
)]
/// - `O_NONBLOCK`: Set the non-blocking flag for the ends of the pipe.
///
#[cfg(any(
linux_android,
freebsdlike,
solarish,
target_os = "emscripten",
target_os = "hurd",
target_os = "redox",
netbsdlike,
))]
pub fn pipe2(flags: OFlag) -> Result<(OwnedFd, OwnedFd)> {
let mut fds = mem::MaybeUninit::<[OwnedFd; 2]>::uninit();
let res =
unsafe { libc::pipe2(fds.as_mut_ptr().cast(), flags.bits()) };
Errno::result(res)?;
let [read, write] = unsafe { fds.assume_init() };
Ok((read, write))
}
/// Truncate a file to a specified length
///
/// See also
#[cfg(not(any(target_os = "redox", target_os = "fuchsia")))]
pub fn truncate<P: ?Sized + NixPath>(path: &P, len: off_t) -> Result<()> {
let res = path
.with_nix_path(|cstr| unsafe { libc::truncate(cstr.as_ptr(), len) })?;
Errno::result(res).map(drop)
}
/// Truncate a file to a specified length
///
/// See also
pub fn ftruncate<Fd: AsFd>(fd: Fd, len: off_t) -> Result<()> {
Errno::result(unsafe { libc::ftruncate(fd.as_fd().as_raw_fd(), len) }).map(drop)
}
/// Determines if the file descriptor refers to a valid terminal type device.
pub fn isatty(fd: RawFd) -> Result<bool> {
unsafe {
// ENOTTY means `fd` is a valid file descriptor, but not a TTY, so
// we return `Ok(false)`
if libc::isatty(fd) == 1 {
Ok(true)
} else {
match Errno::last() {
Errno::ENOTTY => Ok(false),
err => Err(err),
}
}
}
}
#[allow(missing_docs)]
#[cfg(not(target_os = "redox"))]
pub type LinkatFlags = AtFlags;
#[allow(missing_docs)]
#[cfg(not(target_os = "redox"))]
impl LinkatFlags {
#[deprecated(since = "0.28.0", note = "The variant is deprecated, please use `AtFlags` instead")]
#[allow(non_upper_case_globals)]
pub const SymlinkFollow: LinkatFlags = LinkatFlags::AT_SYMLINK_FOLLOW;
#[deprecated(since = "0.28.0", note = "The variant is deprecated, please use `AtFlags` instead")]
#[allow(non_upper_case_globals)]
pub const NoSymlinkFollow: LinkatFlags = LinkatFlags::empty();
}
/// Link one file to another file
///
/// Creates a new link (directory entry) at `newpath` for the existing file at `oldpath`. In the
/// case of a relative `oldpath`, the path is interpreted relative to the directory associated
/// with file descriptor `olddirfd` instead of the current working directory and similiarly for
/// `newpath` and file descriptor `newdirfd`. In case `flag` is `AtFlags::AT_SYMLINK_FOLLOW` and
/// `oldpath` names a symoblic link, a new link for the target of the symbolic link is created.
/// If either `olddirfd` or `newdirfd` is `None`, `AT_FDCWD` is used respectively where `oldpath`
/// and/or `newpath` is then interpreted relative to the current working directory of the calling
/// process. If either `oldpath` or `newpath` is absolute, then `dirfd` is ignored.
///
/// # References
#[cfg(not(target_os = "redox"))] // RedoxFS does not support symlinks yet
pub fn linkat<P: ?Sized + NixPath>(
olddirfd: Option<RawFd>,
oldpath: &P,
newdirfd: Option<RawFd>,
newpath: &P,
flag: AtFlags,
) -> Result<()> {
let res = oldpath.with_nix_path(|oldcstr| {
newpath.with_nix_path(|newcstr| unsafe {
libc::linkat(
at_rawfd(olddirfd),
oldcstr.as_ptr(),
at_rawfd(newdirfd),
newcstr.as_ptr(),
flag.bits(),
)
})
})??;
Errno::result(res).map(drop)
}
/// Remove a directory entry
///
pub fn unlink<P: ?Sized + NixPath>(path: &P) -> Result<()> {
let res =
path.with_nix_path(|cstr| unsafe { libc::unlink(cstr.as_ptr()) })?;
Errno::result(res).map(drop)
}
/// Flags for `unlinkat` function.
#[derive(Clone, Copy, Debug)]
pub enum UnlinkatFlags {
/// Remove the directory entry as a directory, not a normal file
RemoveDir,
/// Remove the directory entry as a normal file, not a directory
NoRemoveDir,
}
/// Remove a directory entry
///
/// In the case of a relative path, the directory entry to be removed is determined relative to
/// the directory associated with the file descriptor `dirfd` or the current working directory
/// if `dirfd` is `None`. In the case of an absolute `path` `dirfd` is ignored. If `flag` is
/// `UnlinkatFlags::RemoveDir` then removal of the directory entry specified by `dirfd` and `path`
/// is performed.
///
/// # References
#[cfg(not(target_os = "redox"))]
pub fn unlinkat<P: ?Sized + NixPath>(
dirfd: Option<RawFd>,
path: &P,
flag: UnlinkatFlags,
) -> Result<()> {
let atflag = match flag {
UnlinkatFlags::RemoveDir => AtFlags::AT_REMOVEDIR,
UnlinkatFlags::NoRemoveDir => AtFlags::empty(),
};
let res = path.with_nix_path(|cstr| unsafe {
libc::unlinkat(
at_rawfd(dirfd),
cstr.as_ptr(),
atflag.bits() as libc::c_int,
)
})?;
Errno::result(res).map(drop)
}
/// Change a process's root directory
#[inline]
#[cfg(not(target_os = "fuchsia"))]
pub fn chroot<P: ?Sized + NixPath>(path: &P) -> Result<()> {
let res =
path.with_nix_path(|cstr| unsafe { libc::chroot(cstr.as_ptr()) })?;
Errno::result(res).map(drop)
}
/// Commit filesystem caches to disk
///
#[cfg(any(bsd, linux_android, solarish, target_os = "haiku", target_os = "aix", target_os = "hurd"))]
pub fn sync() {
unsafe { libc::sync() };
}
/// Commit filesystem caches containing file referred to by the open file
/// descriptor `fd` to disk
///
#[cfg(any(linux_android, target_os = "hurd"))]
pub fn syncfs(fd: RawFd) -> Result<()> {
let res = unsafe { libc::syncfs(fd) };
Errno::result(res).map(drop)
}
/// Synchronize changes to a file
///
#[inline]
pub fn fsync(fd: RawFd) -> Result<()> {
let res = unsafe { libc::fsync(fd) };
Errno::result(res).map(drop)
}
/// Synchronize the data of a file
///
/// See also
#[cfg(any(
linux_android,
solarish,
netbsdlike,
apple_targets,
target_os = "freebsd",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "aix",
target_os = "hurd",
))]
#[inline]
pub fn fdatasync(fd: RawFd) -> Result<()> {
cfg_if! {
// apple libc supports fdatasync too, albeit not being present in its headers
if #[cfg(apple_targets)] {
extern "C" {
fn fdatasync(fd: libc::c_int) -> libc::c_int;
}
} else {
use libc::fdatasync as fdatasync;
}
}
let res = unsafe { fdatasync(fd) };
Errno::result(res).map(drop)
}
}
feature! {
#![feature = "user"]
/// Get a real user ID
///
// POSIX requires that getuid is always successful, so no need to check return
// value or errno.
#[inline]
pub fn getuid() -> Uid {
Uid(unsafe { libc::getuid() })
}
/// Get the effective user ID
///
// POSIX requires that geteuid is always successful, so no need to check return
// value or errno.
#[inline]
pub fn geteuid() -> Uid {
Uid(unsafe { libc::geteuid() })
}
/// Get the real group ID
///
// POSIX requires that getgid is always successful, so no need to check return
// value or errno.
#[inline]
pub fn getgid() -> Gid {
Gid(unsafe { libc::getgid() })
}
/// Get the effective group ID
///
// POSIX requires that getegid is always successful, so no need to check return
// value or errno.
#[inline]
pub fn getegid() -> Gid {
Gid(unsafe { libc::getegid() })
}
/// Set the effective user ID
///
#[inline]
pub fn seteuid(euid: Uid) -> Result<()> {
let res = unsafe { libc::seteuid(euid.into()) };
Errno::result(res).map(drop)
}
/// Set the effective group ID
///
#[inline]
pub fn setegid(egid: Gid) -> Result<()> {
let res = unsafe { libc::setegid(egid.into()) };
Errno::result(res).map(drop)
}
/// Set the user ID
///
#[inline]
pub fn setuid(uid: Uid) -> Result<()> {
let res = unsafe { libc::setuid(uid.into()) };
Errno::result(res).map(drop)
}
/// Set the group ID
///
#[inline]
pub fn setgid(gid: Gid) -> Result<()> {
let res = unsafe { libc::setgid(gid.into()) };
Errno::result(res).map(drop)
}
}
feature! {
#![all(feature = "fs", feature = "user")]
/// Set the user identity used for filesystem checks per-thread.
/// On both success and failure, this call returns the previous filesystem user
/// ID of the caller.
///
#[cfg(linux_android)]
pub fn setfsuid(uid: Uid) -> Uid {
let prev_fsuid = unsafe { libc::setfsuid(uid.into()) };
Uid::from_raw(prev_fsuid as uid_t)
}
/// Set the group identity used for filesystem checks per-thread.
/// On both success and failure, this call returns the previous filesystem group
/// ID of the caller.
///
#[cfg(linux_android)]
pub fn setfsgid(gid: Gid) -> Gid {
let prev_fsgid = unsafe { libc::setfsgid(gid.into()) };
Gid::from_raw(prev_fsgid as gid_t)
}
}
feature! {
#![feature = "user"]
/// Get the list of supplementary group IDs of the calling process.
///
///
/// **Note:** This function is not available for Apple platforms. On those
/// platforms, checking group membership should be achieved via communication
/// with the `opendirectoryd` service.
#[cfg(not(apple_targets))]
pub fn getgroups() -> Result<Vec<Gid>> {
// First get the maximum number of groups. The value returned
// shall always be greater than or equal to one and less than or
// equal to the value of {NGROUPS_MAX} + 1.
let ngroups_max = match sysconf(SysconfVar::NGROUPS_MAX) {
Ok(Some(n)) => (n + 1) as usize,
Ok(None) | Err(_) => usize::MAX,
};
// Next, get the number of groups so we can size our Vec
let ngroups = unsafe { libc::getgroups(0, ptr::null_mut()) };
// If there are no supplementary groups, return early.
// This prevents a potential buffer over-read if the number of groups
// increases from zero before the next call. It would return the total
// number of groups beyond the capacity of the buffer.
if ngroups == 0 {
return Ok(Vec::new());
}
// Now actually get the groups. We try multiple times in case the number of
// groups has changed since the first call to getgroups() and the buffer is
// now too small.
let mut groups =
Vec::<Gid>::with_capacity(Errno::result(ngroups)? as usize);
loop {
// FIXME: On the platforms we currently support, the `Gid` struct has
// the same representation in memory as a bare `gid_t`. This is not
// necessarily the case on all Rust platforms, though. See RFC 1785.
let ngroups = unsafe {
libc::getgroups(
groups.capacity() as c_int,
groups.as_mut_ptr().cast(),
)
};
match Errno::result(ngroups) {
Ok(s) => {
unsafe { groups.set_len(s as usize) };
return Ok(groups);
}
Err(Errno::EINVAL) => {
// EINVAL indicates that the buffer size was too
// small, resize it up to ngroups_max as limit.
reserve_double_buffer_size(&mut groups, ngroups_max)
.or(Err(Errno::EINVAL))?;
}
Err(e) => return Err(e),
}
}
}
/// Set the list of supplementary group IDs for the calling process.
///
///
/// **Note:** This function is not available for Apple platforms. On those
/// platforms, group membership management should be achieved via communication
/// with the `opendirectoryd` service.
///
/// # Examples
///
/// `setgroups` can be used when dropping privileges from the root user to a
/// specific user and group. For example, given the user `www-data` with UID
/// `33` and the group `backup` with the GID `34`, one could switch the user as
/// follows:
///
/// ```rust,no_run
/// # use std::error::Error;
/// # use nix::unistd::*;
/// #
/// # fn try_main() -> Result<(), Box<dyn Error>> {
/// let uid = Uid::from_raw(33);
/// let gid = Gid::from_raw(34);
/// setgroups(&[gid])?;
/// setgid(gid)?;
/// setuid(uid)?;
/// #
/// # Ok(())
/// # }
/// #
/// # try_main().unwrap();
/// ```
#[cfg(not(any(
apple_targets,
target_os = "redox",
target_os = "haiku"
)))]
pub fn setgroups(groups: &[Gid]) -> Result<()> {
cfg_if! {
if #[cfg(any(bsd,
solarish,
target_os = "aix"))] {
type setgroups_ngroups_t = c_int;
} else {
type setgroups_ngroups_t = size_t;
}
}
// FIXME: On the platforms we currently support, the `Gid` struct has the
// same representation in memory as a bare `gid_t`. This is not necessarily
// the case on all Rust platforms, though. See RFC 1785.
let res = unsafe {
libc::setgroups(
groups.len() as setgroups_ngroups_t,
groups.as_ptr().cast(),
)
};
Errno::result(res).map(drop)
}
/// Calculate the supplementary group access list.
///
/// Gets the group IDs of all groups that `user` is a member of. The additional
/// group `group` is also added to the list.
///
///
/// **Note:** This function is not available for Apple platforms. On those
/// platforms, checking group membership should be achieved via communication
/// with the `opendirectoryd` service.
///
/// # Errors
///
/// Although the `getgrouplist()` call does not return any specific
/// errors on any known platforms, this implementation will return a system
/// error of `EINVAL` if the number of groups to be fetched exceeds the
/// `NGROUPS_MAX` sysconf value. This mimics the behaviour of `getgroups()`
/// and `setgroups()`. Additionally, while some implementations will return a
/// partial list of groups when `NGROUPS_MAX` is exceeded, this implementation
/// will only ever return the complete list or else an error.
#[cfg(not(any(
target_os = "aix",
solarish,
apple_targets,
target_os = "redox"
)))]
pub fn getgrouplist(user: &CStr, group: Gid) -> Result<Vec<Gid>> {
let ngroups_max = match sysconf(SysconfVar::NGROUPS_MAX) {
Ok(Some(n)) => n as c_int,
Ok(None) | Err(_) => c_int::MAX,
};
use std::cmp::min;
let mut groups = Vec::<Gid>::with_capacity(min(ngroups_max, 8) as usize);
cfg_if! {
if #[cfg(apple_targets)] {
type getgrouplist_group_t = c_int;
} else {
type getgrouplist_group_t = gid_t;
}
}
let gid: gid_t = group.into();
loop {
let mut ngroups = groups.capacity() as i32;
let ret = unsafe {
libc::getgrouplist(
user.as_ptr(),
gid as getgrouplist_group_t,
groups.as_mut_ptr().cast(),
&mut ngroups,
)
};
// BSD systems only return 0 or -1, Linux returns ngroups on success.
if ret >= 0 {
unsafe { groups.set_len(ngroups as usize) };
return Ok(groups);
} else if ret == -1 {
// Returns -1 if ngroups is too small, but does not set errno.
// BSD systems will still fill the groups buffer with as many
// groups as possible, but Linux manpages do not mention this
// behavior.
reserve_double_buffer_size(&mut groups, ngroups_max as usize)
.map_err(|_| Errno::EINVAL)?;
}
}
}
/// Initialize the supplementary group access list.
///
/// Sets the supplementary group IDs for the calling process using all groups
/// that `user` is a member of. The additional group `group` is also added to
/// the list.
///
///
/// **Note:** This function is not available for Apple platforms. On those
/// platforms, group membership management should be achieved via communication
/// with the `opendirectoryd` service.
///
/// # Examples
///
/// `initgroups` can be used when dropping privileges from the root user to
/// another user. For example, given the user `www-data`, we could look up the
/// UID and GID for the user in the system's password database (usually found
/// in `/etc/passwd`). If the `www-data` user's UID and GID were `33` and `33`,
/// respectively, one could switch the user as follows:
///
/// ```rust,no_run
/// # use std::error::Error;
/// # use std::ffi::CString;
/// # use nix::unistd::*;
/// #
/// # fn try_main() -> Result<(), Box<dyn Error>> {
/// let user = CString::new("www-data").unwrap();
/// let uid = Uid::from_raw(33);
/// let gid = Gid::from_raw(33);
/// initgroups(&user, gid)?;
/// setgid(gid)?;
/// setuid(uid)?;
/// #
/// # Ok(())
/// # }
/// #
/// # try_main().unwrap();
/// ```
#[cfg(not(any(
apple_targets,
target_os = "redox",
target_os = "haiku"
)))]
pub fn initgroups(user: &CStr, group: Gid) -> Result<()> {
cfg_if! {
if #[cfg(apple_targets)] {
type initgroups_group_t = c_int;
} else {
type initgroups_group_t = gid_t;
}
}
let gid: gid_t = group.into();
let res =
unsafe { libc::initgroups(user.as_ptr(), gid as initgroups_group_t) };
Errno::result(res).map(drop)
}
}
feature! {
#![feature = "signal"]
/// Suspend the thread until a signal is received.
///
#[inline]
#[cfg(not(target_os = "redox"))]
pub fn pause() {
unsafe { libc::pause() };
}
pub mod alarm {
//! Alarm signal scheduling.
//!
//! Scheduling an alarm will trigger a `SIGALRM` signal when the time has
//! elapsed, which has to be caught, because the default action for the
//! signal is to terminate the program. This signal also can't be ignored
//! because the system calls like `pause` will not be interrupted, see the
//! second example below.
//!
//! # Examples
//!
//! Canceling an alarm:
//!
//! ```
//! use nix::unistd::alarm;
//!
//! // Set an alarm for 60 seconds from now.
//! alarm::set(60);
//!
//! // Cancel the above set alarm, which returns the number of seconds left
//! // of the previously set alarm.
//! assert_eq!(alarm::cancel(), Some(60));
//! ```
//!
//! Scheduling an alarm and waiting for the signal:
//!
#![cfg_attr(target_os = "redox", doc = " ```rust,ignore")]
#![cfg_attr(not(target_os = "redox"), doc = " ```rust")]
//! use std::time::{Duration, Instant};
//!
//! use nix::unistd::{alarm, pause};
//! use nix::sys::signal::*;
//!
//! // We need to setup an empty signal handler to catch the alarm signal,
//! // otherwise the program will be terminated once the signal is delivered.
//! extern fn signal_handler(_: nix::libc::c_int) { }
//! let sa = SigAction::new(
//! SigHandler::Handler(signal_handler),
//! SaFlags::SA_RESTART,
//! SigSet::empty()
//! );
//! unsafe {
//! sigaction(Signal::SIGALRM, &sa);
//! }
//!
//! let start = Instant::now();
//!
//! // Set an alarm for 1 second from now.
//! alarm::set(1);
//!
//! // Pause the process until the alarm signal is received.
//! let mut sigset = SigSet::empty();
//! sigset.add(Signal::SIGALRM);
//! sigset.wait();
//!
//! assert!(start.elapsed() >= Duration::from_secs(1));
//! ```
//!
//! # References
//!
/// Schedule an alarm signal.
///
/// This will cause the system to generate a `SIGALRM` signal for the
/// process after the specified number of seconds have elapsed.
///
/// Returns the leftover time of a previously set alarm if there was one.
pub fn set(secs: libc::c_uint) -> Option<libc::c_uint> {
assert!(secs != 0, "passing 0 to `alarm::set` is not allowed, to cancel an alarm use `alarm::cancel`");
alarm(secs)
}
/// Cancel an previously set alarm signal.
///
/// Returns the leftover time of a previously set alarm if there was one.
pub fn cancel() -> Option<libc::c_uint> {
alarm(0)
}
fn alarm(secs: libc::c_uint) -> Option<libc::c_uint> {
match unsafe { libc::alarm(secs) } {
0 => None,
secs => Some(secs),
}
}
}
}
/// Suspend execution for an interval of time
///
// Per POSIX, does not fail
#[inline]
pub fn sleep(seconds: c_uint) -> c_uint {
unsafe { libc::sleep(seconds) }
}
feature! {
#![feature = "acct"]
/// Process accounting
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
pub mod acct {
use crate::errno::Errno;
use crate::{NixPath, Result};
use std::ptr;
/// Enable process accounting
///
/// See also [acct(2)](https://linux.die.net/man/2/acct)
pub fn enable<P: ?Sized + NixPath>(filename: &P) -> Result<()> {
let res = filename
.with_nix_path(|cstr| unsafe { libc::acct(cstr.as_ptr()) })?;
Errno::result(res).map(drop)
}
/// Disable process accounting
pub fn disable() -> Result<()> {
let res = unsafe { libc::acct(ptr::null()) };
Errno::result(res).map(drop)
}
}
}
feature! {
#![feature = "fs"]
/// Creates a regular file which persists even after process termination
///
/// * `template`: a path whose 6 rightmost characters must be X, e.g. `/tmp/tmpfile_XXXXXX`
/// * returns: tuple of file descriptor and filename
///
/// Err is returned either if no temporary filename could be created or the template doesn't
/// end with XXXXXX
///
///
/// # Example
///
/// ```rust
/// use nix::unistd;
///
/// let _ = match unistd::mkstemp("/tmp/tempfile_XXXXXX") {
/// Ok((fd, path)) => {
/// unistd::unlink(path.as_path()).unwrap(); // flag file to be deleted at app termination
/// fd
/// }
/// Err(e) => panic!("mkstemp failed: {}", e)
/// };
/// // do something with fd
/// ```
#[inline]
pub fn mkstemp<P: ?Sized + NixPath>(template: &P) -> Result<(RawFd, PathBuf)> {
let mut path =
template.with_nix_path(|path| path.to_bytes_with_nul().to_owned())?;
let p = path.as_mut_ptr().cast();
let fd = unsafe { libc::mkstemp(p) };
let last = path.pop(); // drop the trailing nul
debug_assert!(last == Some(b'\0'));
let pathname = OsString::from_vec(path);
Errno::result(fd)?;
Ok((fd, PathBuf::from(pathname)))
}
}
feature! {
#![all(feature = "fs", feature = "feature")]
/// Creates a directory which persists even after process termination
///
/// * `template`: a path whose rightmost characters contain some number of X, e.g. `/tmp/tmpdir_XXXXXX`
/// * returns: filename
///
/// Err is returned either if no temporary filename could be created or the template had insufficient X
///
///
/// ```
/// use nix::unistd;
///
/// match unistd::mkdtemp("/tmp/tempdir_XXXXXX") {
/// Ok(_path) => {
/// // do something with directory
/// }
/// Err(e) => panic!("mkdtemp failed: {}", e)
/// };
/// ```
pub fn mkdtemp<P: ?Sized + NixPath>(template: &P) -> Result<PathBuf> {
let mut path = template.with_nix_path(|path| {path.to_bytes_with_nul().to_owned()})?;
let p = path.as_mut_ptr() as *mut _;
let p = unsafe { libc::mkdtemp(p) };
if p.is_null() {
return Err(Errno::last());
}
let last = path.pop(); // drop the trailing nul
debug_assert!(last == Some(b'\0'));
let pathname = OsString::from_vec(path);
Ok(PathBuf::from(pathname))
}
/// Variable names for `pathconf`
///
/// Nix uses the same naming convention for these variables as the
/// That is, `PathconfVar` variables have the same name as the abstract
/// variables shown in the `pathconf(2)` man page. Usually, it's the same as
/// the C variable name without the leading `_PC_`.
///
/// POSIX 1003.1-2008 standardizes all of these variables, but some OSes choose
/// not to implement variables that cannot change at runtime.
///
/// # References
///
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
#[repr(i32)]
#[non_exhaustive]
pub enum PathconfVar {
#[cfg(any(
freebsdlike,
netbsdlike,
target_os = "linux",
target_os = "redox"
))]
/// Minimum number of bits needed to represent, as a signed integer value,
/// the maximum size of a regular file allowed in the specified directory.
FILESIZEBITS = libc::_PC_FILESIZEBITS,
/// Maximum number of links to a single file.
LINK_MAX = libc::_PC_LINK_MAX,
/// Maximum number of bytes in a terminal canonical input line.
MAX_CANON = libc::_PC_MAX_CANON,
/// Minimum number of bytes for which space is available in a terminal input
/// queue; therefore, the maximum number of bytes a conforming application
/// may require to be typed as input before reading them.
MAX_INPUT = libc::_PC_MAX_INPUT,
#[cfg(any(
apple_targets,
solarish,
freebsdlike,
target_os = "netbsd",
))]
/// If a file system supports the reporting of holes (see lseek(2)),
/// pathconf() and fpathconf() return a positive number that represents the
/// minimum hole size returned in bytes. The offsets of holes returned will
/// be aligned to this same value. A special value of 1 is returned if the
/// file system does not specify the minimum hole size but still reports
/// holes.
MIN_HOLE_SIZE = libc::_PC_MIN_HOLE_SIZE,
/// Maximum number of bytes in a filename (not including the terminating
/// null of a filename string).
NAME_MAX = libc::_PC_NAME_MAX,
/// Maximum number of bytes the implementation will store as a pathname in a
/// user-supplied buffer of unspecified size, including the terminating null
/// character. Minimum number the implementation will accept as the maximum
/// number of bytes in a pathname.
PATH_MAX = libc::_PC_PATH_MAX,
/// Maximum number of bytes that is guaranteed to be atomic when writing to
/// a pipe.
PIPE_BUF = libc::_PC_PIPE_BUF,
#[cfg(any(
linux_android,
solarish,
netbsdlike,
target_os = "dragonfly",
target_os = "redox",
))]
/// Symbolic links can be created.
POSIX2_SYMLINKS = libc::_PC_2_SYMLINKS,
#[cfg(any(
linux_android,
freebsdlike,
target_os = "openbsd",
target_os = "redox"
))]
/// Minimum number of bytes of storage actually allocated for any portion of
/// a file.
POSIX_ALLOC_SIZE_MIN = libc::_PC_ALLOC_SIZE_MIN,
#[cfg(any(
freebsdlike,
linux_android,
target_os = "openbsd"
))]
/// Recommended increment for file transfer sizes between the
/// `POSIX_REC_MIN_XFER_SIZE` and `POSIX_REC_MAX_XFER_SIZE` values.
POSIX_REC_INCR_XFER_SIZE = libc::_PC_REC_INCR_XFER_SIZE,
#[cfg(any(
linux_android,
freebsdlike,
target_os = "openbsd",
target_os = "redox"
))]
/// Maximum recommended file transfer size.
POSIX_REC_MAX_XFER_SIZE = libc::_PC_REC_MAX_XFER_SIZE,
#[cfg(any(
linux_android,
freebsdlike,
target_os = "openbsd",
target_os = "redox"
))]
/// Minimum recommended file transfer size.
POSIX_REC_MIN_XFER_SIZE = libc::_PC_REC_MIN_XFER_SIZE,
#[cfg(any(
linux_android,
freebsdlike,
target_os = "openbsd",
target_os = "redox"
))]
/// Recommended file transfer buffer alignment.
POSIX_REC_XFER_ALIGN = libc::_PC_REC_XFER_ALIGN,
#[cfg(any(
linux_android,
freebsdlike,
solarish,
netbsdlike,
target_os = "redox",
))]
/// Maximum number of bytes in a symbolic link.
SYMLINK_MAX = libc::_PC_SYMLINK_MAX,
/// The use of `chown` and `fchown` is restricted to a process with
/// appropriate privileges, and to changing the group ID of a file only to
/// the effective group ID of the process or to one of its supplementary
/// group IDs.
_POSIX_CHOWN_RESTRICTED = libc::_PC_CHOWN_RESTRICTED,
/// Pathname components longer than {NAME_MAX} generate an error.
_POSIX_NO_TRUNC = libc::_PC_NO_TRUNC,
/// This symbol shall be defined to be the value of a character that shall
/// disable terminal special character handling.
_POSIX_VDISABLE = libc::_PC_VDISABLE,
#[cfg(any(
linux_android,
freebsdlike,
solarish,
target_os = "openbsd",
target_os = "redox",
))]
/// Asynchronous input or output operations may be performed for the
/// associated file.
_POSIX_ASYNC_IO = libc::_PC_ASYNC_IO,
#[cfg(any(
linux_android,
freebsdlike,
solarish,
target_os = "openbsd",
target_os = "redox",
))]
/// Prioritized input or output operations may be performed for the
/// associated file.
_POSIX_PRIO_IO = libc::_PC_PRIO_IO,
#[cfg(any(
linux_android,
freebsdlike,
solarish,
netbsdlike,
target_os = "redox",
))]
/// Synchronized input or output operations may be performed for the
/// associated file.
_POSIX_SYNC_IO = libc::_PC_SYNC_IO,
#[cfg(any(target_os = "dragonfly", target_os = "openbsd"))]
/// The resolution in nanoseconds for all file timestamps.
_POSIX_TIMESTAMP_RESOLUTION = libc::_PC_TIMESTAMP_RESOLUTION,
}
/// Like `pathconf`, but works with file descriptors instead of paths (see
///
/// # Parameters
///
/// - `fd`: The file descriptor whose variable should be interrogated
/// - `var`: The pathconf variable to lookup
///
/// # Returns
///
/// - `Ok(Some(x))`: the variable's limit (for limit variables) or its
/// implementation level (for option variables). Implementation levels are
/// usually a decimal-coded date, such as 200112 for POSIX 2001.12
/// - `Ok(None)`: the variable has no limit (for limit variables) or is
/// unsupported (for option variables)
/// - `Err(x)`: an error occurred
pub fn fpathconf<F: AsFd>(fd: F, var: PathconfVar) -> Result<Option<c_long>> {
let raw = unsafe {
Errno::clear();
libc::fpathconf(fd.as_fd().as_raw_fd(), var as c_int)
};
if raw == -1 {
if Errno::last_raw() == 0 {
Ok(None)
} else {
Err(Errno::last())
}
} else {
Ok(Some(raw))
}
}
/// Get path-dependent configurable system variables (see
///
/// Returns the value of a path-dependent configurable system variable. Most
/// supported variables also have associated compile-time constants, but POSIX
/// allows their values to change at runtime. There are generally two types of
/// `pathconf` variables: options and limits. See [pathconf(2)](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pathconf.html) for more details.
///
/// # Parameters
///
/// - `path`: Lookup the value of `var` for this file or directory
/// - `var`: The `pathconf` variable to lookup
///
/// # Returns
///
/// - `Ok(Some(x))`: the variable's limit (for limit variables) or its
/// implementation level (for option variables). Implementation levels are
/// usually a decimal-coded date, such as 200112 for POSIX 2001.12
/// - `Ok(None)`: the variable has no limit (for limit variables) or is
/// unsupported (for option variables)
/// - `Err(x)`: an error occurred
pub fn pathconf<P: ?Sized + NixPath>(
path: &P,
var: PathconfVar,
) -> Result<Option<c_long>> {
let raw = path.with_nix_path(|cstr| unsafe {
Errno::clear();
libc::pathconf(cstr.as_ptr(), var as c_int)
})?;
if raw == -1 {
if Errno::last_raw() == 0 {
Ok(None)
} else {
Err(Errno::last())
}
} else {
Ok(Some(raw))
}
}
}
feature! {
#![feature = "feature"]
/// Variable names for `sysconf`
///
/// Nix uses the same naming convention for these variables as the
/// That is, `SysconfVar` variables have the same name as the abstract variables
/// shown in the `sysconf(3)` man page. Usually, it's the same as the C
/// variable name without the leading `_SC_`.
///
/// All of these symbols are standardized by POSIX 1003.1-2008, but haven't been
/// implemented by all platforms.
///
/// # References
///
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
#[repr(i32)]
#[non_exhaustive]
pub enum SysconfVar {
/// Maximum number of I/O operations in a single list I/O call supported by
/// the implementation.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
AIO_LISTIO_MAX = libc::_SC_AIO_LISTIO_MAX,
/// Maximum number of outstanding asynchronous I/O operations supported by
/// the implementation.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
AIO_MAX = libc::_SC_AIO_MAX,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The maximum amount by which a process can decrease its asynchronous I/O
/// priority level from its own scheduling priority.
AIO_PRIO_DELTA_MAX = libc::_SC_AIO_PRIO_DELTA_MAX,
/// Maximum length of argument to the exec functions including environment data.
ARG_MAX = libc::_SC_ARG_MAX,
/// Maximum number of functions that may be registered with `atexit`.
#[cfg(not(target_os = "redox"))]
ATEXIT_MAX = libc::_SC_ATEXIT_MAX,
/// Maximum obase values allowed by the bc utility.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
BC_BASE_MAX = libc::_SC_BC_BASE_MAX,
/// Maximum number of elements permitted in an array by the bc utility.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
BC_DIM_MAX = libc::_SC_BC_DIM_MAX,
/// Maximum scale value allowed by the bc utility.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
BC_SCALE_MAX = libc::_SC_BC_SCALE_MAX,
/// Maximum length of a string constant accepted by the bc utility.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
BC_STRING_MAX = libc::_SC_BC_STRING_MAX,
/// Maximum number of simultaneous processes per real user ID.
CHILD_MAX = libc::_SC_CHILD_MAX,
/// The frequency of the statistics clock in ticks per second.
CLK_TCK = libc::_SC_CLK_TCK,
/// Maximum number of weights that can be assigned to an entry of the
/// LC_COLLATE order keyword in the locale definition file
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
COLL_WEIGHTS_MAX = libc::_SC_COLL_WEIGHTS_MAX,
/// Maximum number of timer expiration overruns.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
DELAYTIMER_MAX = libc::_SC_DELAYTIMER_MAX,
/// Maximum number of expressions that can be nested within parentheses by
/// the expr utility.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
EXPR_NEST_MAX = libc::_SC_EXPR_NEST_MAX,
#[cfg(any(bsd, solarish, target_os = "linux"))]
/// Maximum length of a host name (not including the terminating null) as
/// returned from the `gethostname` function
HOST_NAME_MAX = libc::_SC_HOST_NAME_MAX,
/// Maximum number of iovec structures that one process has available for
/// use with `readv` or `writev`.
#[cfg(not(target_os = "redox"))]
IOV_MAX = libc::_SC_IOV_MAX,
/// Unless otherwise noted, the maximum length, in bytes, of a utility's
/// input line (either standard input or another file), when the utility is
/// described as processing text files. The length includes room for the
/// trailing newline.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
LINE_MAX = libc::_SC_LINE_MAX,
/// Maximum length of a login name.
#[cfg(not(target_os = "haiku"))]
LOGIN_NAME_MAX = libc::_SC_LOGIN_NAME_MAX,
/// Maximum number of simultaneous supplementary group IDs per process.
NGROUPS_MAX = libc::_SC_NGROUPS_MAX,
/// Initial size of `getgrgid_r` and `getgrnam_r` data buffers
#[cfg(not(target_os = "redox"))]
GETGR_R_SIZE_MAX = libc::_SC_GETGR_R_SIZE_MAX,
/// Initial size of `getpwuid_r` and `getpwnam_r` data buffers
#[cfg(not(target_os = "redox"))]
GETPW_R_SIZE_MAX = libc::_SC_GETPW_R_SIZE_MAX,
/// The maximum number of open message queue descriptors a process may hold.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
MQ_OPEN_MAX = libc::_SC_MQ_OPEN_MAX,
/// The maximum number of message priorities supported by the implementation.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
MQ_PRIO_MAX = libc::_SC_MQ_PRIO_MAX,
/// A value one greater than the maximum value that the system may assign to
/// a newly-created file descriptor.
OPEN_MAX = libc::_SC_OPEN_MAX,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Advisory Information option.
_POSIX_ADVISORY_INFO = libc::_SC_ADVISORY_INFO,
#[cfg(any(bsd, solarish, target_os = "linux"))]
/// The implementation supports barriers.
_POSIX_BARRIERS = libc::_SC_BARRIERS,
/// The implementation supports asynchronous input and output.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_ASYNCHRONOUS_IO = libc::_SC_ASYNCHRONOUS_IO,
#[cfg(any(bsd, solarish, target_os = "linux"))]
/// The implementation supports clock selection.
_POSIX_CLOCK_SELECTION = libc::_SC_CLOCK_SELECTION,
#[cfg(any(bsd, solarish, target_os = "linux"))]
/// The implementation supports the Process CPU-Time Clocks option.
_POSIX_CPUTIME = libc::_SC_CPUTIME,
/// The implementation supports the File Synchronization option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_FSYNC = libc::_SC_FSYNC,
#[cfg(any(
freebsdlike,
apple_targets,
solarish,
target_os = "linux",
target_os = "openbsd",
))]
/// The implementation supports the IPv6 option.
_POSIX_IPV6 = libc::_SC_IPV6,
/// The implementation supports job control.
#[cfg(not(target_os = "redox"))]
_POSIX_JOB_CONTROL = libc::_SC_JOB_CONTROL,
/// The implementation supports memory mapped Files.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_MAPPED_FILES = libc::_SC_MAPPED_FILES,
/// The implementation supports the Process Memory Locking option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_MEMLOCK = libc::_SC_MEMLOCK,
/// The implementation supports the Range Memory Locking option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_MEMLOCK_RANGE = libc::_SC_MEMLOCK_RANGE,
/// The implementation supports memory protection.
#[cfg(not(target_os = "redox"))]
_POSIX_MEMORY_PROTECTION = libc::_SC_MEMORY_PROTECTION,
/// The implementation supports the Message Passing option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_MESSAGE_PASSING = libc::_SC_MESSAGE_PASSING,
/// The implementation supports the Monotonic Clock option.
#[cfg(not(target_os = "redox"))]
_POSIX_MONOTONIC_CLOCK = libc::_SC_MONOTONIC_CLOCK,
#[cfg(any(
linux_android,
freebsdlike,
solarish,
apple_targets,
target_os = "openbsd",
))]
/// The implementation supports the Prioritized Input and Output option.
_POSIX_PRIORITIZED_IO = libc::_SC_PRIORITIZED_IO,
/// The implementation supports the Process Scheduling option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_PRIORITY_SCHEDULING = libc::_SC_PRIORITY_SCHEDULING,
#[cfg(any(
freebsdlike,
solarish,
apple_targets,
target_os = "linux",
target_os = "openbsd",
))]
/// The implementation supports the Raw Sockets option.
_POSIX_RAW_SOCKETS = libc::_SC_RAW_SOCKETS,
#[cfg(any(
bsd,
solarish,
target_os = "linux",
))]
/// The implementation supports read-write locks.
_POSIX_READER_WRITER_LOCKS = libc::_SC_READER_WRITER_LOCKS,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports realtime signals.
_POSIX_REALTIME_SIGNALS = libc::_SC_REALTIME_SIGNALS,
#[cfg(any(
bsd,
solarish,
target_os = "linux",
))]
/// The implementation supports the Regular Expression Handling option.
_POSIX_REGEXP = libc::_SC_REGEXP,
/// Each process has a saved set-user-ID and a saved set-group-ID.
#[cfg(not(target_os = "redox"))]
_POSIX_SAVED_IDS = libc::_SC_SAVED_IDS,
/// The implementation supports semaphores.
#[cfg(not(target_os = "redox"))]
_POSIX_SEMAPHORES = libc::_SC_SEMAPHORES,
/// The implementation supports the Shared Memory Objects option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_SHARED_MEMORY_OBJECTS = libc::_SC_SHARED_MEMORY_OBJECTS,
#[cfg(any(bsd, target_os = "linux",))]
/// The implementation supports the POSIX shell.
_POSIX_SHELL = libc::_SC_SHELL,
#[cfg(any(bsd, target_os = "linux",))]
/// The implementation supports the Spawn option.
_POSIX_SPAWN = libc::_SC_SPAWN,
#[cfg(any(bsd, target_os = "linux",))]
/// The implementation supports spin locks.
_POSIX_SPIN_LOCKS = libc::_SC_SPIN_LOCKS,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Process Sporadic Server option.
_POSIX_SPORADIC_SERVER = libc::_SC_SPORADIC_SERVER,
/// The number of replenishment operations that can be simultaneously pending for a particular
/// sporadic server scheduler.
#[cfg(any(
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
_POSIX_SS_REPL_MAX = libc::_SC_SS_REPL_MAX,
/// The implementation supports the Synchronized Input and Output option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_SYNCHRONIZED_IO = libc::_SC_SYNCHRONIZED_IO,
/// The implementation supports the Thread Stack Address Attribute option.
#[cfg(not(target_os = "redox"))]
_POSIX_THREAD_ATTR_STACKADDR = libc::_SC_THREAD_ATTR_STACKADDR,
/// The implementation supports the Thread Stack Size Attribute option.
#[cfg(not(target_os = "redox"))]
_POSIX_THREAD_ATTR_STACKSIZE = libc::_SC_THREAD_ATTR_STACKSIZE,
#[cfg(any(
apple_targets,
target_os = "linux",
netbsdlike,
))]
/// The implementation supports the Thread CPU-Time Clocks option.
_POSIX_THREAD_CPUTIME = libc::_SC_THREAD_CPUTIME,
/// The implementation supports the Non-Robust Mutex Priority Inheritance
/// option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_THREAD_PRIO_INHERIT = libc::_SC_THREAD_PRIO_INHERIT,
/// The implementation supports the Non-Robust Mutex Priority Protection option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_THREAD_PRIO_PROTECT = libc::_SC_THREAD_PRIO_PROTECT,
/// The implementation supports the Thread Execution Scheduling option.
#[cfg(not(target_os = "redox"))]
_POSIX_THREAD_PRIORITY_SCHEDULING = libc::_SC_THREAD_PRIORITY_SCHEDULING,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Thread Process-Shared Synchronization
/// option.
_POSIX_THREAD_PROCESS_SHARED = libc::_SC_THREAD_PROCESS_SHARED,
#[cfg(any(
target_os = "dragonfly",
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Robust Mutex Priority Inheritance option.
_POSIX_THREAD_ROBUST_PRIO_INHERIT = libc::_SC_THREAD_ROBUST_PRIO_INHERIT,
#[cfg(any(
target_os = "dragonfly",
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Robust Mutex Priority Protection option.
_POSIX_THREAD_ROBUST_PRIO_PROTECT = libc::_SC_THREAD_ROBUST_PRIO_PROTECT,
/// The implementation supports thread-safe functions.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX_THREAD_SAFE_FUNCTIONS = libc::_SC_THREAD_SAFE_FUNCTIONS,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Thread Sporadic Server option.
_POSIX_THREAD_SPORADIC_SERVER = libc::_SC_THREAD_SPORADIC_SERVER,
/// The implementation supports threads.
#[cfg(not(target_os = "redox"))]
_POSIX_THREADS = libc::_SC_THREADS,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports timeouts.
_POSIX_TIMEOUTS = libc::_SC_TIMEOUTS,
/// The implementation supports timers.
#[cfg(not(target_os = "redox"))]
_POSIX_TIMERS = libc::_SC_TIMERS,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Trace option.
_POSIX_TRACE = libc::_SC_TRACE,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Trace Event Filter option.
_POSIX_TRACE_EVENT_FILTER = libc::_SC_TRACE_EVENT_FILTER,
/// Maximum size of a trace event name in characters.
#[cfg(any(
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
_POSIX_TRACE_EVENT_NAME_MAX = libc::_SC_TRACE_EVENT_NAME_MAX,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Trace Inherit option.
_POSIX_TRACE_INHERIT = libc::_SC_TRACE_INHERIT,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Trace Log option.
_POSIX_TRACE_LOG = libc::_SC_TRACE_LOG,
/// The length in bytes of a trace generation version string or a trace stream name.
#[cfg(any(
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
_POSIX_TRACE_NAME_MAX = libc::_SC_TRACE_NAME_MAX,
/// Maximum number of times `posix_trace_create` may be called from the same or different
/// processes.
#[cfg(any(
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
_POSIX_TRACE_SYS_MAX = libc::_SC_TRACE_SYS_MAX,
/// Maximum number of user trace event type identifiers for a single process.
#[cfg(any(
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
_POSIX_TRACE_USER_EVENT_MAX = libc::_SC_TRACE_USER_EVENT_MAX,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the Typed Memory Objects option.
_POSIX_TYPED_MEMORY_OBJECTS = libc::_SC_TYPED_MEMORY_OBJECTS,
/// Integer value indicating version of this standard (C-language binding)
/// to which the implementation conforms. For implementations conforming to
/// POSIX.1-2008, the value shall be 200809L.
_POSIX_VERSION = libc::_SC_VERSION,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation provides a C-language compilation environment with
/// 32-bit `int`, `long`, `pointer`, and `off_t` types.
_POSIX_V6_ILP32_OFF32 = libc::_SC_V6_ILP32_OFF32,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation provides a C-language compilation environment with
/// 32-bit `int`, `long`, and pointer types and an `off_t` type using at
/// least 64 bits.
_POSIX_V6_ILP32_OFFBIG = libc::_SC_V6_ILP32_OFFBIG,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation provides a C-language compilation environment with
/// 32-bit `int` and 64-bit `long`, `pointer`, and `off_t` types.
_POSIX_V6_LP64_OFF64 = libc::_SC_V6_LP64_OFF64,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation provides a C-language compilation environment with an
/// `int` type using at least 32 bits and `long`, pointer, and `off_t` types
/// using at least 64 bits.
_POSIX_V6_LPBIG_OFFBIG = libc::_SC_V6_LPBIG_OFFBIG,
/// The implementation supports the C-Language Binding option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_C_BIND = libc::_SC_2_C_BIND,
/// The implementation supports the C-Language Development Utilities option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_C_DEV = libc::_SC_2_C_DEV,
/// The implementation supports the Terminal Characteristics option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_CHAR_TERM = libc::_SC_2_CHAR_TERM,
/// The implementation supports the FORTRAN Development Utilities option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_FORT_DEV = libc::_SC_2_FORT_DEV,
/// The implementation supports the FORTRAN Runtime Utilities option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_FORT_RUN = libc::_SC_2_FORT_RUN,
/// The implementation supports the creation of locales by the localedef
/// utility.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_LOCALEDEF = libc::_SC_2_LOCALEDEF,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Batch Environment Services and Utilities
/// option.
_POSIX2_PBS = libc::_SC_2_PBS,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Batch Accounting option.
_POSIX2_PBS_ACCOUNTING = libc::_SC_2_PBS_ACCOUNTING,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Batch Checkpoint/Restart option.
_POSIX2_PBS_CHECKPOINT = libc::_SC_2_PBS_CHECKPOINT,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Locate Batch Job Request option.
_POSIX2_PBS_LOCATE = libc::_SC_2_PBS_LOCATE,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Batch Job Message Request option.
_POSIX2_PBS_MESSAGE = libc::_SC_2_PBS_MESSAGE,
#[cfg(any(bsd, target_os = "linux"))]
/// The implementation supports the Track Batch Job Request option.
_POSIX2_PBS_TRACK = libc::_SC_2_PBS_TRACK,
/// The implementation supports the Software Development Utilities option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_SW_DEV = libc::_SC_2_SW_DEV,
/// The implementation supports the User Portability Utilities option.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_UPE = libc::_SC_2_UPE,
/// Integer value indicating version of the Shell and Utilities volume of
/// POSIX.1 to which the implementation conforms.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_POSIX2_VERSION = libc::_SC_2_VERSION,
/// The size of a system page in bytes.
///
/// POSIX also defines an alias named `PAGESIZE`, but Rust does not allow two
/// enum constants to have the same value, so nix omits `PAGESIZE`.
PAGE_SIZE = libc::_SC_PAGE_SIZE,
/// Maximum number of attempts made to destroy a thread's thread-specific data values on thread
/// exit.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
PTHREAD_DESTRUCTOR_ITERATIONS = libc::_SC_THREAD_DESTRUCTOR_ITERATIONS,
/// Maximum number of data keys that can be created by a process.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
PTHREAD_KEYS_MAX = libc::_SC_THREAD_KEYS_MAX,
/// Minimum size in bytes of thread stack storage.
#[cfg(not(target_os = "redox"))]
PTHREAD_STACK_MIN = libc::_SC_THREAD_STACK_MIN,
/// Maximum number of threads that can be created per process.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
PTHREAD_THREADS_MAX = libc::_SC_THREAD_THREADS_MAX,
/// The maximum number of repeated occurrences of a regular expression permitted when using
/// interval notation.
#[cfg(not(target_os = "haiku"))]
RE_DUP_MAX = libc::_SC_RE_DUP_MAX,
/// Maximum number of realtime signals reserved for application use.
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
RTSIG_MAX = libc::_SC_RTSIG_MAX,
/// Maximum number of semaphores that a process may have.
#[cfg(not(target_os = "redox"))]
SEM_NSEMS_MAX = libc::_SC_SEM_NSEMS_MAX,
/// The maximum value a semaphore may have.
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
SEM_VALUE_MAX = libc::_SC_SEM_VALUE_MAX,
/// Maximum number of queued signals that a process may send and have pending at the
/// receiver(s) at any time.
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
SIGQUEUE_MAX = libc::_SC_SIGQUEUE_MAX,
/// The minimum maximum number of streams that a process may have open at any one time.
STREAM_MAX = libc::_SC_STREAM_MAX,
/// Maximum number of symbolic links that can be reliably traversed in the resolution of a
/// pathname in the absence of a loop.
#[cfg(any(bsd, target_os = "linux"))]
SYMLOOP_MAX = libc::_SC_SYMLOOP_MAX,
/// Maximum number of timers per process supported.
#[cfg(not(target_os = "redox"))]
TIMER_MAX = libc::_SC_TIMER_MAX,
/// Maximum length of terminal device name.
TTY_NAME_MAX = libc::_SC_TTY_NAME_MAX,
/// The minimum maximum number of types supported for the name of a timezone.
TZNAME_MAX = libc::_SC_TZNAME_MAX,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports the X/Open Encryption Option Group.
_XOPEN_CRYPT = libc::_SC_XOPEN_CRYPT,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports the Issue 4, Version 2 Enhanced
/// Internationalization Option Group.
_XOPEN_ENH_I18N = libc::_SC_XOPEN_ENH_I18N,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports the XOpen Legacy Option group.
///
_XOPEN_LEGACY = libc::_SC_XOPEN_LEGACY,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports the X/Open Realtime Option Group.
_XOPEN_REALTIME = libc::_SC_XOPEN_REALTIME,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports the X/Open Realtime Threads Option Group.
_XOPEN_REALTIME_THREADS = libc::_SC_XOPEN_REALTIME_THREADS,
/// The implementation supports the Issue 4, Version 2 Shared Memory Option
/// Group.
#[cfg(not(any(target_os = "redox", target_os = "haiku")))]
_XOPEN_SHM = libc::_SC_XOPEN_SHM,
#[cfg(any(
freebsdlike,
apple_targets,
target_os = "linux",
target_os = "openbsd"
))]
/// The implementation supports the XSI STREAMS Option Group.
_XOPEN_STREAMS = libc::_SC_XOPEN_STREAMS,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// The implementation supports the XSI option
_XOPEN_UNIX = libc::_SC_XOPEN_UNIX,
#[cfg(any(
linux_android,
freebsdlike,
apple_targets,
target_os = "openbsd"
))]
/// Integer value indicating version of the X/Open Portability Guide to
/// which the implementation conforms.
_XOPEN_VERSION = libc::_SC_XOPEN_VERSION,
/// The number of pages of physical memory. Note that it is possible for
/// the product of this value to overflow.
#[cfg(linux_android)]
_PHYS_PAGES = libc::_SC_PHYS_PAGES,
/// The number of currently available pages of physical memory.
#[cfg(linux_android)]
_AVPHYS_PAGES = libc::_SC_AVPHYS_PAGES,
/// The number of processors configured.
#[cfg(linux_android)]
_NPROCESSORS_CONF = libc::_SC_NPROCESSORS_CONF,
/// The number of processors currently online (available).
#[cfg(linux_android)]
_NPROCESSORS_ONLN = libc::_SC_NPROCESSORS_ONLN,
}
/// Get configurable system variables (see
///
/// Returns the value of a configurable system variable. Most supported
/// variables also have associated compile-time constants, but POSIX
/// allows their values to change at runtime. There are generally two types of
/// sysconf variables: options and limits. See sysconf(3) for more details.
///
/// # Returns
///
/// - `Ok(Some(x))`: the variable's limit (for limit variables) or its
/// implementation level (for option variables). Implementation levels are
/// usually a decimal-coded date, such as 200112 for POSIX 2001.12
/// - `Ok(None)`: the variable has no limit (for limit variables) or is
/// unsupported (for option variables)
/// - `Err(x)`: an error occurred
pub fn sysconf(var: SysconfVar) -> Result<Option<c_long>> {
let raw = unsafe {
Errno::clear();
libc::sysconf(var as c_int)
};
if raw == -1 {
if Errno::last_raw() == 0 {
Ok(None)
} else {
Err(Errno::last())
}
} else {
Ok(Some(raw))
}
}
}
#[cfg(linux_android)]
#[cfg(feature = "fs")]
mod pivot_root {
use crate::errno::Errno;
use crate::{NixPath, Result};
/// Change the root file system.
///
pub fn pivot_root<P1: ?Sized + NixPath, P2: ?Sized + NixPath>(
new_root: &P1,
put_old: &P2,
) -> Result<()> {
let res = new_root.with_nix_path(|new_root| {
put_old.with_nix_path(|put_old| unsafe {
libc::syscall(
libc::SYS_pivot_root,
new_root.as_ptr(),
put_old.as_ptr(),
)
})
})??;
Errno::result(res).map(drop)
}
}
#[cfg(any(linux_android, freebsdlike, target_os = "openbsd"))]
mod setres {
feature! {
#![feature = "user"]
use super::{Gid, Uid};
use crate::errno::Errno;
use crate::Result;
/// Sets the real, effective, and saved uid.
///
/// * `ruid`: real user id
/// * `euid`: effective user id
/// * `suid`: saved user id
/// * returns: Ok or libc error code.
///
/// Err is returned if the user doesn't have permission to set this UID.
#[inline]
pub fn setresuid(ruid: Uid, euid: Uid, suid: Uid) -> Result<()> {
let res =
unsafe { libc::setresuid(ruid.into(), euid.into(), suid.into()) };
Errno::result(res).map(drop)
}
/// Sets the real, effective, and saved gid.
///
/// * `rgid`: real group id
/// * `egid`: effective group id
/// * `sgid`: saved group id
/// * returns: Ok or libc error code.
///
/// Err is returned if the user doesn't have permission to set this GID.
#[inline]
pub fn setresgid(rgid: Gid, egid: Gid, sgid: Gid) -> Result<()> {
let res =
unsafe { libc::setresgid(rgid.into(), egid.into(), sgid.into()) };
Errno::result(res).map(drop)
}
}
}
#[cfg(any(linux_android, freebsdlike, target_os = "openbsd"))]
mod getres {
feature! {
#![feature = "user"]
use super::{Gid, Uid};
use crate::errno::Errno;
use crate::Result;
/// Real, effective and saved user IDs.
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct ResUid {
/// Real UID
pub real: Uid,
/// Effective UID
pub effective: Uid,
/// Saved UID
pub saved: Uid,
}
/// Real, effective and saved group IDs.
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct ResGid {
/// Real GID
pub real: Gid,
/// Effective GID
pub effective: Gid,
/// Saved GID
pub saved: Gid,
}
/// Gets the real, effective, and saved user IDs.
///
///
/// #Returns
///
/// - `Ok((Uid, Uid, Uid))`: tuple of real, effective and saved uids on success.
/// - `Err(x)`: libc error code on failure.
///
#[inline]
pub fn getresuid() -> Result<ResUid> {
let mut ruid = libc::uid_t::MAX;
let mut euid = libc::uid_t::MAX;
let mut suid = libc::uid_t::MAX;
let res = unsafe { libc::getresuid(&mut ruid, &mut euid, &mut suid) };
Errno::result(res).map(|_| ResUid {
real: Uid(ruid),
effective: Uid(euid),
saved: Uid(suid),
})
}
/// Gets the real, effective, and saved group IDs.
///
///
/// #Returns
///
/// - `Ok((Gid, Gid, Gid))`: tuple of real, effective and saved gids on success.
/// - `Err(x)`: libc error code on failure.
///
#[inline]
pub fn getresgid() -> Result<ResGid> {
let mut rgid = libc::gid_t::MAX;
let mut egid = libc::gid_t::MAX;
let mut sgid = libc::gid_t::MAX;
let res = unsafe { libc::getresgid(&mut rgid, &mut egid, &mut sgid) };
Errno::result(res).map(|_| ResGid {
real: Gid(rgid),
effective: Gid(egid),
saved: Gid(sgid),
})
}
}
}
#[cfg(feature = "process")]
#[cfg(target_os = "freebsd")]
libc_bitflags! {
/// Flags for [`rfork`]
///
/// subset of flags supported by FreeBSD 12.x and onwards
/// with a safe outcome, thus as `RFMEM` can possibly lead to undefined behavior,
/// it is not in the list. And `rfork_thread` is deprecated.
pub struct RforkFlags: libc::c_int {
/// creates a new process.
RFPROC;
/// the child process will detach from the parent.
/// however, no status will be emitted at child's exit.
RFNOWAIT;
/// the file descriptor's table will be copied
RFFDG;
/// a new file descriptor's table will be created
RFCFDG;
/// force sharing the sigacts structure between
/// the child and the parent.
RFSIGSHARE;
/// enables kernel thread support.
RFTHREAD;
/// sets a status to emit at child's exit.
RFTSIGZMB;
/// linux's behavior compatibility setting.
/// emits SIGUSR1 as opposed to SIGCHLD upon child's exit.
RFLINUXTHPN;
}
}
feature! {
#![feature = "process"]
#[cfg(target_os = "freebsd")]
/// Like [`fork`], `rfork` can be used to have a tigher control about which
/// resources child and parent process will be sharing, file descriptors,
/// address spaces and child exit's behavior.
///
/// # Safety
///
/// The same restrictions apply as for [`fork`].
///
/// # See Also
///
pub unsafe fn rfork(flags: RforkFlags) -> Result<ForkResult> {
use ForkResult::*;
let res = unsafe { libc::rfork(flags.bits()) };
Errno::result(res).map(|res| match res {
0 => Child,
res => Parent { child: Pid(res) },
})
}
}
#[cfg(feature = "fs")]
libc_bitflags! {
/// Options for access()
#[cfg_attr(docsrs, doc(cfg(feature = "fs")))]
pub struct AccessFlags : c_int {
/// Test for existence of file.
F_OK;
/// Test for read permission.
R_OK;
/// Test for write permission.
W_OK;
/// Test for execute (search) permission.
X_OK;
}
}
feature! {
#![feature = "fs"]
/// Checks the file named by `path` for accessibility according to the flags given by `amode`
pub fn access<P: ?Sized + NixPath>(path: &P, amode: AccessFlags) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::access(cstr.as_ptr(), amode.bits())
})?;
Errno::result(res).map(drop)
}
/// Checks the file named by `path` for accessibility according to the flags given by `mode`
///
/// If `dirfd` has a value, then `path` is relative to directory associated with the file descriptor.
///
/// If `dirfd` is `None`, then `path` is relative to the current working directory.
///
/// # References
///
// redox: does not appear to support the *at family of syscalls.
#[cfg(not(target_os = "redox"))]
pub fn faccessat<P: ?Sized + NixPath>(
dirfd: Option<RawFd>,
path: &P,
mode: AccessFlags,
flags: AtFlags,
) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::faccessat(
at_rawfd(dirfd),
cstr.as_ptr(),
mode.bits(),
flags.bits(),
)
})?;
Errno::result(res).map(drop)
}
/// Checks the file named by `path` for accessibility according to the flags given
/// by `mode` using effective UID, effective GID and supplementary group lists.
///
/// # References
///
#[cfg(any(
freebsdlike,
all(target_os = "linux", not(target_env = "uclibc")),
))]
pub fn eaccess<P: ?Sized + NixPath>(path: &P, mode: AccessFlags) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::eaccess(cstr.as_ptr(), mode.bits())
})?;
Errno::result(res).map(drop)
}
}
feature! {
#![feature = "user"]
/// Representation of a User, based on `libc::passwd`
///
/// The reason some fields in this struct are `String` and others are `CString` is because some
/// fields are based on the user's locale, which could be non-UTF8, while other fields are
/// guaranteed to conform to [`NAME_REGEX`](https://serverfault.com/a/73101/407341), which only
/// contains ASCII.
#[cfg(not(target_os = "redox"))] // RedoxFS does not support passwd
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct User {
/// Username
pub name: String,
/// User password (probably hashed)
pub passwd: CString,
/// User ID
pub uid: Uid,
/// Group ID
pub gid: Gid,
/// User information
#[cfg(not(all(target_os = "android", target_pointer_width = "32")))]
pub gecos: CString,
/// Home directory
pub dir: PathBuf,
/// Path to shell
pub shell: PathBuf,
/// Login class
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
pub class: CString,
/// Last password change
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
pub change: libc::time_t,
/// Expiration time of account
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
pub expire: libc::time_t,
}
#[cfg(not(target_os = "redox"))] //RedoxFS does not support passwd
impl From<&libc::passwd> for User {
fn from(pw: &libc::passwd) -> User {
unsafe {
User {
name: if pw.pw_name.is_null() {
Default::default()
} else {
CStr::from_ptr(pw.pw_name).to_string_lossy().into_owned()
},
passwd: if pw.pw_passwd.is_null() {
Default::default()
} else {
CString::new(CStr::from_ptr(pw.pw_passwd).to_bytes())
.unwrap()
},
#[cfg(not(all(
target_os = "android",
target_pointer_width = "32"
)))]
gecos: if pw.pw_gecos.is_null() {
Default::default()
} else {
CString::new(CStr::from_ptr(pw.pw_gecos).to_bytes())
.unwrap()
},
dir: if pw.pw_dir.is_null() {
Default::default()
} else {
PathBuf::from(OsStr::from_bytes(
CStr::from_ptr(pw.pw_dir).to_bytes(),
))
},
shell: if pw.pw_shell.is_null() {
Default::default()
} else {
PathBuf::from(OsStr::from_bytes(
CStr::from_ptr(pw.pw_shell).to_bytes(),
))
},
uid: Uid::from_raw(pw.pw_uid),
gid: Gid::from_raw(pw.pw_gid),
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
class: CString::new(CStr::from_ptr(pw.pw_class).to_bytes())
.unwrap(),
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
change: pw.pw_change,
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
expire: pw.pw_expire,
}
}
}
}
#[cfg(not(target_os = "redox"))] // RedoxFS does not support passwd
impl From<User> for libc::passwd {
fn from(u: User) -> Self {
let name = match CString::new(u.name) {
Ok(n) => n.into_raw(),
Err(_) => CString::new("").unwrap().into_raw(),
};
let dir = match u.dir.into_os_string().into_string() {
Ok(s) => CString::new(s.as_str()).unwrap().into_raw(),
Err(_) => CString::new("").unwrap().into_raw(),
};
let shell = match u.shell.into_os_string().into_string() {
Ok(s) => CString::new(s.as_str()).unwrap().into_raw(),
Err(_) => CString::new("").unwrap().into_raw(),
};
Self {
pw_name: name,
pw_passwd: u.passwd.into_raw(),
#[cfg(not(all(
target_os = "android",
target_pointer_width = "32"
)))]
pw_gecos: u.gecos.into_raw(),
pw_dir: dir,
pw_shell: shell,
pw_uid: u.uid.0,
pw_gid: u.gid.0,
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
pw_class: u.class.into_raw(),
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
pw_change: u.change,
#[cfg(not(any(
linux_android,
solarish,
target_os = "aix",
target_os = "fuchsia",
target_os = "haiku",
target_os = "hurd",
)))]
pw_expire: u.expire,
#[cfg(solarish)]
pw_age: CString::new("").unwrap().into_raw(),
#[cfg(solarish)]
pw_comment: CString::new("").unwrap().into_raw(),
#[cfg(freebsdlike)]
pw_fields: 0,
}
}
}
#[cfg(not(target_os = "redox"))] // RedoxFS does not support passwd
impl User {
/// # Safety
///
/// If `f` writes to its `*mut *mut libc::passwd` parameter, then it must
/// also initialize the value pointed to by its `*mut libc::group`
/// parameter.
unsafe fn from_anything<F>(f: F) -> Result<Option<Self>>
where
F: Fn(
*mut libc::passwd,
*mut c_char,
libc::size_t,
*mut *mut libc::passwd,
) -> libc::c_int,
{
let buflimit = 1048576;
let bufsize = match sysconf(SysconfVar::GETPW_R_SIZE_MAX) {
Ok(Some(n)) => n as usize,
Ok(None) | Err(_) => 16384,
};
let mut cbuf = Vec::with_capacity(bufsize);
let mut pwd = mem::MaybeUninit::<libc::passwd>::uninit();
let mut res = ptr::null_mut();
loop {
let error = f(
pwd.as_mut_ptr(),
cbuf.as_mut_ptr(),
cbuf.capacity(),
&mut res,
);
if error == 0 {
if res.is_null() {
return Ok(None);
} else {
// SAFETY: `f` guarantees that `pwd` is initialized if `res`
// is not null.
let pwd = unsafe { pwd.assume_init() };
return Ok(Some(User::from(&pwd)));
}
} else if Errno::last() == Errno::ERANGE {
// Trigger the internal buffer resizing logic.
reserve_double_buffer_size(&mut cbuf, buflimit)?;
} else {
return Err(Errno::last());
}
}
}
/// Get a user by UID.
///
/// Internally, this function calls
///
/// # Examples
///
/// ```
/// use nix::unistd::{Uid, User};
/// // Returns an Result<Option<User>>, thus the double unwrap.
/// let res = User::from_uid(Uid::from_raw(0)).unwrap().unwrap();
/// assert_eq!(res.name, "root");
/// ```
pub fn from_uid(uid: Uid) -> Result<Option<Self>> {
// SAFETY: `getpwuid_r` will write to `res` if it initializes the value
// at `pwd`.
unsafe {
User::from_anything(|pwd, cbuf, cap, res| {
libc::getpwuid_r(uid.0, pwd, cbuf, cap, res)
})
}
}
/// Get a user by name.
///
/// Internally, this function calls
///
/// # Examples
///
/// ```
/// use nix::unistd::User;
/// // Returns an Result<Option<User>>, thus the double unwrap.
/// let res = User::from_name("root").unwrap().unwrap();
/// assert_eq!(res.name, "root");
/// ```
pub fn from_name(name: &str) -> Result<Option<Self>> {
let name = match CString::new(name) {
Ok(c_str) => c_str,
Err(_nul_error) => return Ok(None),
};
// SAFETY: `getpwnam_r` will write to `res` if it initializes the value
// at `pwd`.
unsafe {
User::from_anything(|pwd, cbuf, cap, res| {
libc::getpwnam_r(name.as_ptr(), pwd, cbuf, cap, res)
})
}
}
}
/// Representation of a Group, based on `libc::group`
#[cfg(not(target_os = "redox"))] // RedoxFS does not support passwd
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Group {
/// Group name
pub name: String,
/// Group password
pub passwd: CString,
/// Group ID
pub gid: Gid,
/// List of Group members
pub mem: Vec<String>,
}
#[cfg(not(target_os = "redox"))] // RedoxFS does not support passwd
impl From<&libc::group> for Group {
fn from(gr: &libc::group) -> Group {
unsafe {
Group {
name: if gr.gr_name.is_null() {
Default::default()
} else {
CStr::from_ptr(gr.gr_name).to_string_lossy().into_owned()
},
passwd: if gr.gr_passwd.is_null() {
Default::default()
} else {
CString::new(CStr::from_ptr(gr.gr_passwd).to_bytes())
.unwrap()
},
gid: Gid::from_raw(gr.gr_gid),
mem: if gr.gr_mem.is_null() {
Default::default()
} else {
Group::members(gr.gr_mem)
},
}
}
}
}
#[cfg(not(target_os = "redox"))] // RedoxFS does not support passwd
impl Group {
unsafe fn members(mem: *mut *mut c_char) -> Vec<String> {
let mut ret = Vec::new();
for i in 0.. {
let u = unsafe { mem.offset(i).read_unaligned() };
if u.is_null() {
break;
} else {
let s = unsafe {CStr::from_ptr(u).to_string_lossy().into_owned()};
ret.push(s);
}
}
ret
}
/// # Safety
///
/// If `f` writes to its `*mut *mut libc::group` parameter, then it must
/// also initialize the value pointed to by its `*mut libc::group`
/// parameter.
unsafe fn from_anything<F>(f: F) -> Result<Option<Self>>
where
F: Fn(
*mut libc::group,
*mut c_char,
libc::size_t,
*mut *mut libc::group,
) -> libc::c_int,
{
let buflimit = 1048576;
let bufsize = match sysconf(SysconfVar::GETGR_R_SIZE_MAX) {
Ok(Some(n)) => n as usize,
Ok(None) | Err(_) => 16384,
};
let mut cbuf = Vec::with_capacity(bufsize);
let mut grp = mem::MaybeUninit::<libc::group>::uninit();
let mut res = ptr::null_mut();
loop {
let error = f(
grp.as_mut_ptr(),
cbuf.as_mut_ptr(),
cbuf.capacity(),
&mut res,
);
if error == 0 {
if res.is_null() {
return Ok(None);
} else {
// SAFETY: `f` guarantees that `grp` is initialized if `res`
// is not null.
let grp = unsafe { grp.assume_init() };
return Ok(Some(Group::from(&grp)));
}
} else if Errno::last() == Errno::ERANGE {
// Trigger the internal buffer resizing logic.
reserve_double_buffer_size(&mut cbuf, buflimit)?;
} else {
return Err(Errno::last());
}
}
}
/// Get a group by GID.
///
/// Internally, this function calls
///
/// # Examples
///
// Disable this test on all OS except Linux as root group may not exist.
#[cfg_attr(not(target_os = "linux"), doc = " ```no_run")]
#[cfg_attr(target_os = "linux", doc = " ```")]
/// use nix::unistd::{Gid, Group};
/// // Returns an Result<Option<Group>>, thus the double unwrap.
/// let res = Group::from_gid(Gid::from_raw(0)).unwrap().unwrap();
/// assert!(res.name == "root");
/// ```
pub fn from_gid(gid: Gid) -> Result<Option<Self>> {
// SAFETY: `getgrgid_r` will write to `res` if it initializes the value
// at `grp`.
unsafe {
Group::from_anything(|grp, cbuf, cap, res| {
libc::getgrgid_r(gid.0, grp, cbuf, cap, res)
})
}
}
/// Get a group by name.
///
/// Internally, this function calls
///
/// # Examples
///
// Disable this test on all OS except Linux as root group may not exist.
#[cfg_attr(not(target_os = "linux"), doc = " ```no_run")]
#[cfg_attr(target_os = "linux", doc = " ```")]
/// use nix::unistd::Group;
/// // Returns an Result<Option<Group>>, thus the double unwrap.
/// let res = Group::from_name("root").unwrap().unwrap();
/// assert!(res.name == "root");
/// ```
pub fn from_name(name: &str) -> Result<Option<Self>> {
let name = match CString::new(name) {
Ok(c_str) => c_str,
Err(_nul_error) => return Ok(None),
};
// SAFETY: `getgrnam_r` will write to `res` if it initializes the value
// at `grp`.
unsafe {
Group::from_anything(|grp, cbuf, cap, res| {
libc::getgrnam_r(name.as_ptr(), grp, cbuf, cap, res)
})
}
}
}
}
feature! {
#![feature = "term"]
/// Get the name of the terminal device that is open on file descriptor fd
#[cfg(not(target_os = "fuchsia"))]
pub fn ttyname<F: AsFd>(fd: F) -> Result<PathBuf> {
#[cfg(not(target_os = "hurd"))]
const PATH_MAX: usize = libc::PATH_MAX as usize;
#[cfg(target_os = "hurd")]
const PATH_MAX: usize = 1024; // Hurd does not define a hard limit, so try a guess first
let mut buf = vec![0_u8; PATH_MAX];
let c_buf = buf.as_mut_ptr().cast();
let ret = unsafe { libc::ttyname_r(fd.as_fd().as_raw_fd(), c_buf, buf.len()) };
if ret != 0 {
return Err(Errno::from_raw(ret));
}
CStr::from_bytes_until_nul(&buf[..])
.map(|s| OsStr::from_bytes(s.to_bytes()).into())
.map_err(|_| Errno::EINVAL)
}
}
feature! {
#![all(feature = "socket", feature = "user")]
/// Get the effective user ID and group ID associated with a Unix domain socket.
///
#[cfg(bsd)]
pub fn getpeereid<F: AsFd>(fd: F) -> Result<(Uid, Gid)> {
let mut uid = 1;
let mut gid = 1;
let ret = unsafe { libc::getpeereid(fd.as_fd().as_raw_fd(), &mut uid, &mut gid) };
Errno::result(ret).map(|_| (Uid(uid), Gid(gid)))
}
}
feature! {
#![all(feature = "fs")]
/// Set the file flags.
///
#[cfg(bsd)]
pub fn chflags<P: ?Sized + NixPath>(path: &P, flags: FileFlag) -> Result<()> {
let res = path.with_nix_path(|cstr| unsafe {
libc::chflags(cstr.as_ptr(), flags.bits())
})?;
Errno::result(res).map(drop)
}
}