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//! Safe wrappers around functions found in libc "unistd.h" header use errno::{self, Errno}; use {Error, Result, NixPath}; use fcntl::{AtFlags, at_rawfd, fcntl, FdFlag, OFlag}; use fcntl::FcntlArg::F_SETFD; use libc::{self, c_char, c_void, c_int, c_long, c_uint, size_t, pid_t, off_t, uid_t, gid_t, mode_t}; use std::{fmt, mem, ptr}; use std::ffi::{CString, CStr, OsString, OsStr}; use std::os::unix::ffi::{OsStringExt, OsStrExt}; use std::os::unix::io::RawFd; use std::path::PathBuf; use void::Void; use sys::stat::Mode; #[cfg(any(target_os = "android", target_os = "linux"))] pub use self::pivot_root::*; #[cfg(any(target_os = "android", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] pub use self::setres::*; /// 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 fn from_raw(uid: uid_t) -> Self { Uid(uid) } /// Returns Uid of calling process. This is practically a more Rusty alias for `getuid`. pub fn current() -> Self { getuid() } /// Returns effective Uid of calling process. This is practically a more Rusty alias for `geteuid`. pub fn effective() -> Self { geteuid() } /// Returns true if the `Uid` represents privileged user - root. (If it equals zero.) pub fn is_root(&self) -> bool { *self == ROOT } /// Get the raw `uid_t` wrapped by `self`. pub fn as_raw(&self) -> uid_t { self.0 } } impl From<Uid> for uid_t { fn from(uid: Uid) -> Self { uid.0 } } 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 fn from_raw(gid: gid_t) -> Self { Gid(gid) } /// Returns Gid of calling process. This is practically a more Rusty alias for `getgid`. pub fn current() -> Self { getgid() } /// Returns effective Gid of calling process. This is practically a more Rusty alias for `getgid`. pub fn effective() -> Self { getegid() } /// Get the raw `gid_t` wrapped by `self`. pub fn as_raw(&self) -> gid_t { self.0 } } impl From<Gid> for gid_t { fn from(gid: Gid) -> Self { gid.0 } } impl fmt::Display for Gid { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::Display::fmt(&self.0, f) } } /// 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, Hash)] pub struct Pid(pid_t); impl Pid { /// Creates `Pid` from raw `pid_t`. pub fn from_raw(pid: pid_t) -> Self { Pid(pid) } /// Returns PID of calling process pub fn this() -> Self { getpid() } /// Returns PID of parent of calling process pub fn parent() -> Self { getppid() } /// Get the raw `pid_t` wrapped by `self`. pub 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 { Parent { child: Pid }, Child, } impl ForkResult { /// Return `true` if this is the child process of the `fork()` #[inline] pub fn is_child(&self) -> bool { match *self { ForkResult::Child => true, _ => false } } /// 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 /// fork(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fork.html)). /// /// After calling the fork system call (successfully) two processes will /// be created that are identical with the exception of their pid and the /// return value of this function. As an example: /// /// ```no_run /// use nix::unistd::{fork, ForkResult}; /// /// match fork() { /// Ok(ForkResult::Parent { child, .. }) => { /// println!("Continuing execution in parent process, new child has pid: {}", child); /// } /// Ok(ForkResult::Child) => println!("I'm a new child process"), /// Err(_) => println!("Fork failed"), /// } /// ``` /// /// This will print something like the following (order indeterministic). 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. /// /// [async-signal-safe]: http://man7.org/linux/man-pages/man7/signal-safety.7.html #[inline] pub 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 /// [getpid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getpid.html)). /// /// 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 /// [getpid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getppid.html)). /// /// 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 /// [setpgid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setpgid.html)). /// /// 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) } #[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 /// [setsid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setsid.html)). #[inline] pub fn setsid() -> Result<Pid> { Errno::result(unsafe { libc::setsid() }).map(Pid) } /// Get the process group ID of a session leader /// [getsid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getsid.html). /// /// 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] pub fn getsid(pid: Option<Pid>) -> Result<Pid> { let res = unsafe { libc::getsid(pid.unwrap_or(Pid(0)).into()) }; Errno::result(res).map(Pid) } /// Get the terminal foreground process group (see /// [tcgetpgrp(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetpgrp.html)). /// /// Get the group process id (GPID) of the foreground process group on the /// terminal associated to file descriptor (FD). #[inline] pub fn tcgetpgrp(fd: c_int) -> Result<Pid> { let res = unsafe { libc::tcgetpgrp(fd) }; Errno::result(res).map(Pid) } /// Set the terminal foreground process group (see /// [tcgetpgrp(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetpgrp.html)). /// /// Get the group process id (PGID) to the foreground process group on the /// terminal associated to file descriptor (FD). #[inline] pub fn tcsetpgrp(fd: c_int, pgrp: Pid) -> Result<()> { let res = unsafe { libc::tcsetpgrp(fd, pgrp.into()) }; Errno::result(res).map(drop) } /// Get the group id of the calling process (see ///[getpgrp(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getpgrp.html)). /// /// 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 /// [gettid(2)](http://man7.org/linux/man-pages/man2/gettid.2.html). /// /// 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(any(target_os = "linux", target_os = "android"))] #[inline] pub fn gettid() -> Pid { Pid(unsafe { libc::syscall(libc::SYS_gettid) as pid_t }) } /// Create a copy of the specified file descriptor (see /// [dup(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html)). /// /// The new file descriptor will be 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 /// [dup(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html)). /// /// 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)](http://man7.org/linux/man-pages/man2/dup.2.html)). /// /// This function behaves similar to `dup2()` but allows for flags to be /// specified. pub fn dup3(oldfd: RawFd, newfd: RawFd, flags: OFlag) -> Result<RawFd> { dup3_polyfill(oldfd, newfd, flags) } #[inline] fn dup3_polyfill(oldfd: RawFd, newfd: RawFd, flags: OFlag) -> Result<RawFd> { if oldfd == newfd { return Err(Error::Sys(Errno::EINVAL)); } let fd = dup2(oldfd, newfd)?; if flags.contains(OFlag::O_CLOEXEC) { if let Err(e) = fcntl(fd, F_SETFD(FdFlag::FD_CLOEXEC)) { let _ = close(fd); return Err(e); } } Ok(fd) } /// Change the current working directory of the calling process (see /// [chdir(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/chdir.html)). /// /// 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 /// [fchdir(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fchdir.html)). /// /// This function may fail in a number of different scenarios. See the man /// pages for additional details on possible failure cases. #[inline] 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)](http://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 /// extern crate tempfile; /// extern crate nix; /// /// use nix::unistd; /// use nix::sys::stat; /// use tempfile::tempdir; /// /// fn main() { /// 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 /// [posix specification](http://pubs.opengroup.org/onlinepubs/9699919799/functions/mkfifo.html) /// /// # Example /// /// ```rust /// extern crate tempfile; /// extern crate nix; /// /// use nix::unistd; /// use nix::sys::stat; /// use tempfile::tempdir; /// /// fn main() { /// 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] 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 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)`. /// /// See also [symlinkat(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/symlinkat.html). 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) } /// 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 /// extern crate nix; /// /// use nix::unistd; /// /// fn main() { /// // 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::with_capacity(512); loop { unsafe { let ptr = buf.as_mut_ptr() as *mut c_char; // 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() as *const c_char).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::Sys(error)); } } // Trigger the internal buffer resizing logic of `Vec` by requiring // more space than the current capacity. let cap = buf.capacity(); buf.set_len(cap); buf.reserve(1); } } } /// Computes the raw UID and GID values to pass to a `*chown` call. fn chown_raw_ids(owner: Option<Uid>, group: Option<Gid>) -> (libc::uid_t, libc::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((0 as uid_t).wrapping_sub(1)); let gid = group.map(Into::into).unwrap_or((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 /// [chown(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/chown.html)). /// /// 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) } /// Flags for `fchownat` function. #[derive(Clone, Copy, Debug)] pub enum FchownatFlags { FollowSymlink, NoFollowSymlink, } /// 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 `FchownatFlags::NoFollowSymlink` and `path` names a symbolic link, /// then the mode of the symbolic link is changed. /// /// `fchownat(None, path, mode, FchownatFlags::NoFollowSymlink)` is identical to /// a call `libc::lchown(path, mode)`. That's why `lchmod` is unimplemented in /// the `nix` crate. /// /// # References /// /// [fchownat(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fchownat.html). pub fn fchownat<P: ?Sized + NixPath>( dirfd: Option<RawFd>, path: &P, owner: Option<Uid>, group: Option<Gid>, flag: FchownatFlags, ) -> Result<()> { let atflag = match flag { FchownatFlags::FollowSymlink => AtFlags::empty(), FchownatFlags::NoFollowSymlink => AtFlags::AT_SYMLINK_NOFOLLOW, }; 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, atflag.bits() as libc::c_int) })?; Errno::result(res).map(drop) } fn to_exec_array(args: &[CString]) -> Vec<*const c_char> { let mut args_p: Vec<*const c_char> = args.iter().map(|s| s.as_ptr()).collect(); args_p.push(ptr::null()); args_p } /// Replace the current process image with a new one (see /// [exec(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html)). /// /// 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(path: &CString, argv: &[CString]) -> Result<Void> { let args_p = to_exec_array(argv); unsafe { libc::execv(path.as_ptr(), args_p.as_ptr()) }; Err(Error::Sys(Errno::last())) } /// Replace the current process image with a new one (see /// [execve(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html)). /// /// 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(path: &CString, args: &[CString], env: &[CString]) -> Result<Void> { 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(Error::Sys(Errno::last())) } /// Replace the current process image with a new one and replicate shell `PATH` /// searching behavior (see /// [exec(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html)). /// /// 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(filename: &CString, args: &[CString]) -> Result<Void> { let args_p = to_exec_array(args); unsafe { libc::execvp(filename.as_ptr(), args_p.as_ptr()) }; Err(Error::Sys(Errno::last())) } /// Replace the current process image with a new one and replicate shell `PATH` /// searching behavior (see /// [`execvpe(3)`](http://man7.org/linux/man-pages/man3/exec.3.html)). /// /// 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 = "linux", target_os = "openbsd"))] pub fn execvpe(filename: &CString, args: &[CString], env: &[CString]) -> Result<Void> { 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(Error::Sys(Errno::last())) } /// Replace the current process image with a new one (see /// [fexecve(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fexecve.html)). /// /// 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. // Note for NetBSD and OpenBSD: although rust-lang/libc includes it (under // unix/bsd/netbsdlike/) fexecve is not currently implemented on NetBSD nor on // OpenBSD. #[cfg(any(target_os = "android", target_os = "linux", target_os = "freebsd"))] #[inline] pub fn fexecve(fd: RawFd, args: &[CString], env: &[CString]) -> Result<Void> { 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(Error::Sys(Errno::last())) } /// Execute program relative to a directory file descriptor (see /// [execveat(2)](http://man7.org/linux/man-pages/man2/execveat.2.html)). /// /// 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(any(target_os = "android", target_os = "linux"))] #[inline] pub fn execveat(dirfd: RawFd, pathname: &CString, args: &[CString], env: &[CString], flags: super::fcntl::AtFlags) -> Result<Void> { 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(Error::Sys(Errno::last())) } /// Daemonize this process by detaching from the controlling terminal (see /// [daemon(3)](http://man7.org/linux/man-pages/man3/daemon.3.html)). /// /// 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_attr(any(target_os = "macos", target_os = "ios"), deprecated( since="0.14.0", note="Deprecated in MacOSX 10.5" ))] #[cfg_attr(any(target_os = "macos", target_os = "ios"), allow(deprecated))] 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) } /// Set the system host name (see /// [sethostname(2)](http://man7.org/linux/man-pages/man2/gethostname.2.html)). /// /// 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 return if the name is not valid or the current process does not have /// permissions to update the host name. 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(target_os = "dragonfly", target_os = "freebsd", target_os = "ios", target_os = "macos", ))] { type sethostname_len_t = c_int; } else { type sethostname_len_t = size_t; } } let ptr = name.as_ref().as_bytes().as_ptr() as *const c_char; 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 the provided buffer, returning a pointer /// the `CStr` in that buffer on success (see /// [gethostname(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostname.html)). /// /// This function call attempts to get the host name for the running system and /// store it in a provided buffer. The buffer will be populated with bytes up /// to the length of the provided slice including a NUL terminating byte. If /// the hostname is longer than the length provided, no error will be provided. /// The posix specification does not specify whether implementations will /// null-terminate in this case, but the nix implementation will ensure that the /// buffer is null terminated in this case. /// /// ```no_run /// use nix::unistd; /// /// let mut buf = [0u8; 64]; /// let hostname_cstr = unistd::gethostname(&mut buf).expect("Failed getting hostname"); /// let hostname = hostname_cstr.to_str().expect("Hostname wasn't valid UTF-8"); /// println!("Hostname: {}", hostname); /// ``` pub fn gethostname(buffer: &mut [u8]) -> Result<&CStr> { let ptr = buffer.as_mut_ptr() as *mut c_char; let len = buffer.len() as size_t; let res = unsafe { libc::gethostname(ptr, len) }; Errno::result(res).map(|_| { buffer[len - 1] = 0; // ensure always null-terminated unsafe { CStr::from_ptr(buffer.as_ptr() as *const c_char) } }) } /// 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 /// [close(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html). /// /// # Examples /// /// ```no_run /// extern crate tempfile; /// extern crate nix; /// /// use std::os::unix::io::AsRawFd; /// use nix::unistd::close; /// /// fn main() { /// let f = tempfile::tempfile().unwrap(); /// close(f.as_raw_fd()).unwrap(); // Bad! f will also close on drop! /// } /// ``` /// /// ```rust /// extern crate tempfile; /// extern crate nix; /// /// use std::os::unix::io::IntoRawFd; /// use nix::unistd::close; /// /// fn main() { /// 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. /// /// See also [read(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/read.html) pub fn read(fd: RawFd, buf: &mut [u8]) -> Result<usize> { let res = unsafe { libc::read(fd, buf.as_mut_ptr() as *mut c_void, buf.len() as size_t) }; Errno::result(res).map(|r| r as usize) } /// Write to a raw file descriptor. /// /// See also [write(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html) pub fn write(fd: RawFd, buf: &[u8]) -> Result<usize> { let res = unsafe { libc::write(fd, buf.as_ptr() as *const c_void, buf.len() as size_t) }; Errno::result(res).map(|r| r as usize) } /// 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(target_os = "dragonfly", target_os = "freebsd", all(target_os = "linux", not(any(target_env = "musl", target_arch = "mips", target_arch = "mips64")))))] 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(target_os = "dragonfly", target_os = "freebsd", all(target_os = "linux", not(any(target_env = "musl", target_arch = "mips", target_arch = "mips64")))))] SeekHole = libc::SEEK_HOLE } /// Move the read/write file offset. /// /// See also [lseek(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/lseek.html) 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) } #[cfg(any(target_os = "linux", target_os = "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. /// /// See also [pipe(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pipe.html) pub fn pipe() -> Result<(RawFd, RawFd)> { unsafe { let mut fds: [c_int; 2] = mem::uninitialized(); let res = libc::pipe(fds.as_mut_ptr()); Errno::result(res)?; Ok((fds[0], fds[1])) } } /// 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. /// `O_NONBLOCK`: Set the non-blocking flag for the ends of the pipe. /// /// See also [pipe(2)](http://man7.org/linux/man-pages/man2/pipe.2.html) #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "emscripten", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] pub fn pipe2(flags: OFlag) -> Result<(RawFd, RawFd)> { let mut fds: [c_int; 2] = unsafe { mem::uninitialized() }; let res = unsafe { libc::pipe2(fds.as_mut_ptr(), flags.bits()) }; Errno::result(res)?; Ok((fds[0], fds[1])) } /// Like `pipe`, but allows setting certain file descriptor flags. /// /// The following flags are supported, and will be set after the pipe is /// created: /// /// `O_CLOEXEC`: Set the close-on-exec flag for the new file descriptors. /// `O_NONBLOCK`: Set the non-blocking flag for the ends of the pipe. #[cfg(any(target_os = "ios", target_os = "macos"))] #[deprecated( since="0.10.0", note="pipe2(2) is not actually atomic on these platforms. Use pipe(2) and fcntl(2) instead" )] pub fn pipe2(flags: OFlag) -> Result<(RawFd, RawFd)> { let mut fds: [c_int; 2] = unsafe { mem::uninitialized() }; let res = unsafe { libc::pipe(fds.as_mut_ptr()) }; Errno::result(res)?; pipe2_setflags(fds[0], fds[1], flags)?; Ok((fds[0], fds[1])) } #[cfg(any(target_os = "ios", target_os = "macos"))] fn pipe2_setflags(fd1: RawFd, fd2: RawFd, flags: OFlag) -> Result<()> { use fcntl::FcntlArg::F_SETFL; let mut res = Ok(0); if flags.contains(OFlag::O_CLOEXEC) { res = res .and_then(|_| fcntl(fd1, F_SETFD(FdFlag::FD_CLOEXEC))) .and_then(|_| fcntl(fd2, F_SETFD(FdFlag::FD_CLOEXEC))); } if flags.contains(OFlag::O_NONBLOCK) { res = res .and_then(|_| fcntl(fd1, F_SETFL(OFlag::O_NONBLOCK))) .and_then(|_| fcntl(fd2, F_SETFL(OFlag::O_NONBLOCK))); } match res { Ok(_) => Ok(()), Err(e) => { let _ = close(fd1); let _ = close(fd2); Err(e) } } } /// Truncate a file to a specified length /// /// See also /// [truncate(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/truncate.html) 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 /// [ftruncate(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/ftruncate.html) pub fn ftruncate(fd: RawFd, len: off_t) -> Result<()> { Errno::result(unsafe { libc::ftruncate(fd, len) }).map(drop) } 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(Error::Sys(err)), } } } } /// Remove a directory entry /// /// See also [unlink(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/unlink.html) 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) } #[inline] 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 /// /// See also [sync(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/sync.html) #[cfg(any( target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd" ))] pub fn sync() -> () { unsafe { libc::sync() }; } /// Synchronize changes to a file /// /// See also [fsync(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fsync.html) #[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 /// [fdatasync(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fdatasync.html) // `fdatasync(2) is in POSIX, but in libc it is only defined in `libc::notbsd`. // TODO: exclude only Apple systems after https://github.com/rust-lang/libc/pull/211 #[cfg(any(target_os = "linux", target_os = "android", target_os = "emscripten"))] #[inline] pub fn fdatasync(fd: RawFd) -> Result<()> { let res = unsafe { libc::fdatasync(fd) }; Errno::result(res).map(drop) } /// Get a real user ID /// /// See also [getuid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getuid.html) // 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 /// /// See also [geteuid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/geteuid.html) // 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 /// /// See also [getgid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getgid.html) // 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 /// /// See also [getegid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getegid.html) // 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 /// /// See also [seteuid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/seteuid.html) #[inline] pub fn seteuid(euid: Uid) -> Result<()> { let res = unsafe { libc::seteuid(euid.into()) }; Errno::result(res).map(drop) } /// Set the effective group ID /// /// See also [setegid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setegid.html) #[inline] pub fn setegid(egid: Gid) -> Result<()> { let res = unsafe { libc::setegid(egid.into()) }; Errno::result(res).map(drop) } /// Set the user ID /// /// See also [setuid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setuid.html) #[inline] pub fn setuid(uid: Uid) -> Result<()> { let res = unsafe { libc::setuid(uid.into()) }; Errno::result(res).map(drop) } /// Set the group ID /// /// See also [setgid(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setgid.html) #[inline] pub fn setgid(gid: Gid) -> Result<()> { let res = unsafe { libc::setgid(gid.into()) }; Errno::result(res).map(drop) } /// Get the list of supplementary group IDs of the calling process. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/009695399/functions/getgroups.html) /// /// **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(any(target_os = "ios", target_os = "macos")))] pub fn getgroups() -> Result<Vec<Gid>> { // First get the number of groups so we can size our Vec let ret = unsafe { libc::getgroups(0, ptr::null_mut()) }; // 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(ret)? 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 ret = unsafe { libc::getgroups(groups.capacity() as c_int, groups.as_mut_ptr() as *mut gid_t) }; match Errno::result(ret) { Ok(s) => { unsafe { groups.set_len(s as usize) }; return Ok(groups); }, Err(Error::Sys(Errno::EINVAL)) => { // EINVAL indicates that the buffer size was too small. Trigger // the internal buffer resizing logic of `Vec` by requiring // more space than the current capacity. let cap = groups.capacity(); unsafe { groups.set_len(cap) }; groups.reserve(1); }, Err(e) => return Err(e) } } } /// Set the list of supplementary group IDs for the calling process. /// /// [Further reading](http://man7.org/linux/man-pages/man2/getgroups.2.html) /// /// **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<Error>> { /// let uid = Uid::from_raw(33); /// let gid = Gid::from_raw(34); /// setgroups(&[gid])?; /// setgid(gid)?; /// setuid(uid)?; /// # /// # Ok(()) /// # } /// # /// # fn main() { /// # try_main().unwrap(); /// # } /// ``` #[cfg(not(any(target_os = "ios", target_os = "macos")))] pub fn setgroups(groups: &[Gid]) -> Result<()> { cfg_if! { if #[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "ios", target_os = "macos", target_os = "netbsd", target_os = "openbsd"))] { 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() as *const gid_t) }; 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. /// /// [Further reading](http://man7.org/linux/man-pages/man3/getgrouplist.3.html) /// /// **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 = "ios", target_os = "macos")))] 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_value(), }; use std::cmp::min; let mut ngroups = min(ngroups_max, 8); let mut groups = Vec::<Gid>::with_capacity(ngroups as usize); cfg_if! { if #[cfg(any(target_os = "ios", target_os = "macos"))] { type getgrouplist_group_t = c_int; } else { type getgrouplist_group_t = gid_t; } } let gid: gid_t = group.into(); loop { let ret = unsafe { libc::getgrouplist(user.as_ptr(), gid as getgrouplist_group_t, groups.as_mut_ptr() as *mut getgrouplist_group_t, &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. let cap = groups.capacity(); if cap >= ngroups_max as usize { // We already have the largest capacity we can, give up return Err(Error::invalid_argument()); } // Reserve space for at least ngroups groups.reserve(ngroups as usize); // Even if the buffer gets resized to bigger than ngroups_max, // don't ever ask for more than ngroups_max groups ngroups = min(ngroups_max, groups.capacity() as c_int); } } } /// 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. /// /// [Further reading](http://man7.org/linux/man-pages/man3/initgroups.3.html) /// /// **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<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(()) /// # } /// # /// # fn main() { /// # try_main().unwrap(); /// # } /// ``` #[cfg(not(any(target_os = "ios", target_os = "macos")))] pub fn initgroups(user: &CStr, group: Gid) -> Result<()> { cfg_if! { if #[cfg(any(target_os = "ios", target_os = "macos"))] { 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) } /// Suspend the thread until a signal is received. /// /// See also [pause(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pause.html). #[inline] 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: //! //! ``` //! 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) { } //! unsafe { sigaction(Signal::SIGALRM, &SigAction::new(SigHandler::Handler(signal_handler), SaFlags::empty(), SigSet::empty())); } //! //! // Set an alarm for 1 second from now. //! alarm::set(1); //! //! let start = Instant::now(); //! // Pause the process until the alarm signal is received. //! pause(); //! //! assert!(start.elapsed() >= Duration::from_secs(1)); //! ``` //! //! # References //! //! See also [alarm(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/alarm.html). use libc; /// 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 /// /// See also [sleep(2)](http://pubs.opengroup.org/onlinepubs/009695399/functions/sleep.html#tag_03_705_05) // Per POSIX, does not fail #[inline] pub fn sleep(seconds: c_uint) -> c_uint { unsafe { libc::sleep(seconds) } } pub mod acct { use libc; use {Result, NixPath}; use errno::Errno; 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) } } /// 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 /// /// See also [mkstemp(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/mkstemp.html) /// /// # 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() as *mut _; 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))) } /// Variable names for `pathconf` /// /// Nix uses the same naming convention for these variables as the /// [getconf(1)](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getconf.html) utility. /// 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 /// /// - [pathconf(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pathconf.html) /// - [limits.h](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html) /// - [unistd.h](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html) #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] #[repr(i32)] pub enum PathconfVar { #[cfg(any(target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] /// 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, /// 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(target_os = "android", target_os = "dragonfly", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] /// Symbolic links can be created. POSIX2_SYMLINKS = libc::_PC_2_SYMLINKS, #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] /// 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(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", 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(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] /// Maximum recommended file transfer size. POSIX_REC_MAX_XFER_SIZE = libc::_PC_REC_MAX_XFER_SIZE, #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] /// Minimum recommended file transfer size. POSIX_REC_MIN_XFER_SIZE = libc::_PC_REC_MIN_XFER_SIZE, #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] /// Recommended file transfer buffer alignment. POSIX_REC_XFER_ALIGN = libc::_PC_REC_XFER_ALIGN, #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] /// 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(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] /// Asynchronous input or output operations may be performed for the /// associated file. _POSIX_ASYNC_IO = libc::_PC_ASYNC_IO, #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] /// Prioritized input or output operations may be performed for the /// associated file. _POSIX_PRIO_IO = libc::_PC_PRIO_IO, #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] /// 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 /// [fpathconf(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pathconf.html)) /// /// # 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(fd: RawFd, var: PathconfVar) -> Result<Option<c_long>> { let raw = unsafe { Errno::clear(); libc::fpathconf(fd, var as c_int) }; if raw == -1 { if errno::errno() == 0 { Ok(None) } else { Err(Error::Sys(Errno::last())) } } else { Ok(Some(raw)) } } /// Get path-dependent configurable system variables (see /// [pathconf(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/pathconf.html)) /// /// 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)](http://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::errno() == 0 { Ok(None) } else { Err(Error::Sys(Errno::last())) } } else { Ok(Some(raw)) } } /// Variable names for `sysconf` /// /// Nix uses the same naming convention for these variables as the /// [getconf(1)](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getconf.html) utility. /// 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 /// /// - [sysconf(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html) /// - [unistd.h](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html) /// - [limits.h](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html) #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] #[repr(i32)] pub enum SysconfVar { /// Maximum number of I/O operations in a single list I/O call supported by /// the implementation. AIO_LISTIO_MAX = libc::_SC_AIO_LISTIO_MAX, /// Maximum number of outstanding asynchronous I/O operations supported by /// the implementation. AIO_MAX = libc::_SC_AIO_MAX, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", 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`. ATEXIT_MAX = libc::_SC_ATEXIT_MAX, /// Maximum obase values allowed by the bc utility. BC_BASE_MAX = libc::_SC_BC_BASE_MAX, /// Maximum number of elements permitted in an array by the bc utility. BC_DIM_MAX = libc::_SC_BC_DIM_MAX, /// Maximum scale value allowed by the bc utility. BC_SCALE_MAX = libc::_SC_BC_SCALE_MAX, /// Maximum length of a string constant accepted by the bc utility. BC_STRING_MAX = libc::_SC_BC_STRING_MAX, /// Maximum number of simultaneous processes per real user ID. CHILD_MAX = libc::_SC_CHILD_MAX, // _SC_CLK_TCK is obsolete /// Maximum number of weights that can be assigned to an entry of the /// LC_COLLATE order keyword in the locale definition file COLL_WEIGHTS_MAX = libc::_SC_COLL_WEIGHTS_MAX, /// Maximum number of timer expiration overruns. DELAYTIMER_MAX = libc::_SC_DELAYTIMER_MAX, /// Maximum number of expressions that can be nested within parentheses by /// the expr utility. EXPR_NEST_MAX = libc::_SC_EXPR_NEST_MAX, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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`. 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>. LINE_MAX = libc::_SC_LINE_MAX, /// Maximum length of a login name. 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 GETGR_R_SIZE_MAX = libc::_SC_GETGR_R_SIZE_MAX, /// Initial size of `getpwuid_r` and `getpwnam_r` data buffers GETPW_R_SIZE_MAX = libc::_SC_GETPW_R_SIZE_MAX, /// The maximum number of open message queue descriptors a process may hold. MQ_OPEN_MAX = libc::_SC_MQ_OPEN_MAX, /// The maximum number of message priorities supported by the implementation. 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(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Advisory Information option. _POSIX_ADVISORY_INFO = libc::_SC_ADVISORY_INFO, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports barriers. _POSIX_BARRIERS = libc::_SC_BARRIERS, /// The implementation supports asynchronous input and output. _POSIX_ASYNCHRONOUS_IO = libc::_SC_ASYNCHRONOUS_IO, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports clock selection. _POSIX_CLOCK_SELECTION = libc::_SC_CLOCK_SELECTION, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Process CPU-Time Clocks option. _POSIX_CPUTIME = libc::_SC_CPUTIME, /// The implementation supports the File Synchronization option. _POSIX_FSYNC = libc::_SC_FSYNC, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the IPv6 option. _POSIX_IPV6 = libc::_SC_IPV6, /// The implementation supports job control. _POSIX_JOB_CONTROL = libc::_SC_JOB_CONTROL, /// The implementation supports memory mapped Files. _POSIX_MAPPED_FILES = libc::_SC_MAPPED_FILES, /// The implementation supports the Process Memory Locking option. _POSIX_MEMLOCK = libc::_SC_MEMLOCK, /// The implementation supports the Range Memory Locking option. _POSIX_MEMLOCK_RANGE = libc::_SC_MEMLOCK_RANGE, /// The implementation supports memory protection. _POSIX_MEMORY_PROTECTION = libc::_SC_MEMORY_PROTECTION, /// The implementation supports the Message Passing option. _POSIX_MESSAGE_PASSING = libc::_SC_MESSAGE_PASSING, /// The implementation supports the Monotonic Clock option. _POSIX_MONOTONIC_CLOCK = libc::_SC_MONOTONIC_CLOCK, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", 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. _POSIX_PRIORITY_SCHEDULING = libc::_SC_PRIORITY_SCHEDULING, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Raw Sockets option. _POSIX_RAW_SOCKETS = libc::_SC_RAW_SOCKETS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports read-write locks. _POSIX_READER_WRITER_LOCKS = libc::_SC_READER_WRITER_LOCKS, #[cfg(any(target_os = "android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os = "openbsd"))] /// The implementation supports realtime signals. _POSIX_REALTIME_SIGNALS = libc::_SC_REALTIME_SIGNALS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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. _POSIX_SAVED_IDS = libc::_SC_SAVED_IDS, /// The implementation supports semaphores. _POSIX_SEMAPHORES = libc::_SC_SEMAPHORES, /// The implementation supports the Shared Memory Objects option. _POSIX_SHARED_MEMORY_OBJECTS = libc::_SC_SHARED_MEMORY_OBJECTS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the POSIX shell. _POSIX_SHELL = libc::_SC_SHELL, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Spawn option. _POSIX_SPAWN = libc::_SC_SPAWN, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports spin locks. _POSIX_SPIN_LOCKS = libc::_SC_SPIN_LOCKS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Process Sporadic Server option. _POSIX_SPORADIC_SERVER = libc::_SC_SPORADIC_SERVER, #[cfg(any(target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] _POSIX_SS_REPL_MAX = libc::_SC_SS_REPL_MAX, /// The implementation supports the Synchronized Input and Output option. _POSIX_SYNCHRONIZED_IO = libc::_SC_SYNCHRONIZED_IO, /// The implementation supports the Thread Stack Address Attribute option. _POSIX_THREAD_ATTR_STACKADDR = libc::_SC_THREAD_ATTR_STACKADDR, /// The implementation supports the Thread Stack Size Attribute option. _POSIX_THREAD_ATTR_STACKSIZE = libc::_SC_THREAD_ATTR_STACKSIZE, #[cfg(any(target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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. _POSIX_THREAD_PRIO_INHERIT = libc::_SC_THREAD_PRIO_INHERIT, /// The implementation supports the Non-Robust Mutex Priority Protection option. _POSIX_THREAD_PRIO_PROTECT = libc::_SC_THREAD_PRIO_PROTECT, /// The implementation supports the Thread Execution Scheduling option. _POSIX_THREAD_PRIORITY_SCHEDULING = libc::_SC_THREAD_PRIORITY_SCHEDULING, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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. _POSIX_THREAD_SAFE_FUNCTIONS = libc::_SC_THREAD_SAFE_FUNCTIONS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Thread Sporadic Server option. _POSIX_THREAD_SPORADIC_SERVER = libc::_SC_THREAD_SPORADIC_SERVER, /// The implementation supports threads. _POSIX_THREADS = libc::_SC_THREADS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports timeouts. _POSIX_TIMEOUTS = libc::_SC_TIMEOUTS, /// The implementation supports timers. _POSIX_TIMERS = libc::_SC_TIMERS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Trace option. _POSIX_TRACE = libc::_SC_TRACE, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Trace Event Filter option. _POSIX_TRACE_EVENT_FILTER = libc::_SC_TRACE_EVENT_FILTER, #[cfg(any(target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] _POSIX_TRACE_EVENT_NAME_MAX = libc::_SC_TRACE_EVENT_NAME_MAX, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Trace Inherit option. _POSIX_TRACE_INHERIT = libc::_SC_TRACE_INHERIT, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the Trace Log option. _POSIX_TRACE_LOG = libc::_SC_TRACE_LOG, #[cfg(any(target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] _POSIX_TRACE_NAME_MAX = libc::_SC_TRACE_NAME_MAX, #[cfg(any(target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] _POSIX_TRACE_SYS_MAX = libc::_SC_TRACE_SYS_MAX, #[cfg(any(target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] _POSIX_TRACE_USER_EVENT_MAX = libc::_SC_TRACE_USER_EVENT_MAX, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", 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(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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. _POSIX2_C_BIND = libc::_SC_2_C_BIND, /// The implementation supports the C-Language Development Utilities option. _POSIX2_C_DEV = libc::_SC_2_C_DEV, /// The implementation supports the Terminal Characteristics option. _POSIX2_CHAR_TERM = libc::_SC_2_CHAR_TERM, /// The implementation supports the FORTRAN Development Utilities option. _POSIX2_FORT_DEV = libc::_SC_2_FORT_DEV, /// The implementation supports the FORTRAN Runtime Utilities option. _POSIX2_FORT_RUN = libc::_SC_2_FORT_RUN, /// The implementation supports the creation of locales by the localedef /// utility. _POSIX2_LOCALEDEF = libc::_SC_2_LOCALEDEF, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Batch Environment Services and Utilities /// option. _POSIX2_PBS = libc::_SC_2_PBS, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Batch Accounting option. _POSIX2_PBS_ACCOUNTING = libc::_SC_2_PBS_ACCOUNTING, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Batch Checkpoint/Restart option. _POSIX2_PBS_CHECKPOINT = libc::_SC_2_PBS_CHECKPOINT, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Locate Batch Job Request option. _POSIX2_PBS_LOCATE = libc::_SC_2_PBS_LOCATE, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// The implementation supports the Batch Job Message Request option. _POSIX2_PBS_MESSAGE = libc::_SC_2_PBS_MESSAGE, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] /// 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. _POSIX2_SW_DEV = libc::_SC_2_SW_DEV, /// The implementation supports the User Portability Utilities option. _POSIX2_UPE = libc::_SC_2_UPE, /// Integer value indicating version of the Shell and Utilities volume of /// POSIX.1 to which the implementation conforms. _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, PTHREAD_DESTRUCTOR_ITERATIONS = libc::_SC_THREAD_DESTRUCTOR_ITERATIONS, PTHREAD_KEYS_MAX = libc::_SC_THREAD_KEYS_MAX, PTHREAD_STACK_MIN = libc::_SC_THREAD_STACK_MIN, PTHREAD_THREADS_MAX = libc::_SC_THREAD_THREADS_MAX, RE_DUP_MAX = libc::_SC_RE_DUP_MAX, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] RTSIG_MAX = libc::_SC_RTSIG_MAX, SEM_NSEMS_MAX = libc::_SC_SEM_NSEMS_MAX, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] SEM_VALUE_MAX = libc::_SC_SEM_VALUE_MAX, #[cfg(any(target_os = "android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os = "openbsd"))] SIGQUEUE_MAX = libc::_SC_SIGQUEUE_MAX, STREAM_MAX = libc::_SC_STREAM_MAX, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="netbsd", target_os="openbsd"))] SYMLOOP_MAX = libc::_SC_SYMLOOP_MAX, TIMER_MAX = libc::_SC_TIMER_MAX, TTY_NAME_MAX = libc::_SC_TTY_NAME_MAX, TZNAME_MAX = libc::_SC_TZNAME_MAX, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the X/Open Encryption Option Group. _XOPEN_CRYPT = libc::_SC_XOPEN_CRYPT, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", 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(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] _XOPEN_LEGACY = libc::_SC_XOPEN_LEGACY, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the X/Open Realtime Option Group. _XOPEN_REALTIME = libc::_SC_XOPEN_REALTIME, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", 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. _XOPEN_SHM = libc::_SC_XOPEN_SHM, #[cfg(any(target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the XSI STREAMS Option Group. _XOPEN_STREAMS = libc::_SC_XOPEN_STREAMS, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// The implementation supports the XSI option _XOPEN_UNIX = libc::_SC_XOPEN_UNIX, #[cfg(any(target_os="android", target_os="dragonfly", target_os="freebsd", target_os = "ios", target_os="linux", target_os = "macos", target_os="openbsd"))] /// Integer value indicating version of the X/Open Portability Guide to /// which the implementation conforms. _XOPEN_VERSION = libc::_SC_XOPEN_VERSION, } /// Get configurable system variables (see /// [sysconf(3)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html)) /// /// 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::errno() == 0 { Ok(None) } else { Err(Error::Sys(Errno::last())) } } else { Ok(Some(raw)) } } #[cfg(any(target_os = "android", target_os = "linux"))] mod pivot_root { use libc; use {Result, NixPath}; use errno::Errno; 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(target_os = "android", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] mod setres { use libc; use Result; use errno::Errno; use super::{Uid, Gid}; /// Sets the real, effective, and saved uid. /// ([see setresuid(2)](http://man7.org/linux/man-pages/man2/setresuid.2.html)) /// /// * `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. /// ([see setresuid(2)](http://man7.org/linux/man-pages/man2/setresuid.2.html)) /// /// * `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) } } libc_bitflags!{ /// Options for access() 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; } } /// Checks the file named by `path` for accessibility according to the flags given by `amode` /// See [access(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/access.html) 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) }