library/std/src/sys/unix/ext/process.rs - third_party/rust - Git at Google

 //! Unix-specific extensions to primitives in the `std::process` module.

 #![stable(feature = "rust1", since = "1.0.0")]

 use crate::ffi::OsStr;
 use crate::io;
 use crate::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
 use crate::process;
 use crate::sys;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};

 /// Unix-specific extensions to the [`process::Command`] builder.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait CommandExt {
     /// Sets the child process's user ID. This translates to a
     /// `setuid` call in the child process. Failure in the `setuid`
     /// call will cause the spawn to fail.
     #[stable(feature = "rust1", since = "1.0.0")]
     fn uid(&mut self, id: u32) -> &mut process::Command;

     /// Similar to `uid`, but sets the group ID of the child process. This has
     /// the same semantics as the `uid` field.
     #[stable(feature = "rust1", since = "1.0.0")]
     fn gid(&mut self, id: u32) -> &mut process::Command;

     /// Schedules a closure to be run just before the `exec` function is
     /// invoked.
     ///
     /// The closure is allowed to return an I/O error whose OS error code will
     /// be communicated back to the parent and returned as an error from when
     /// the spawn was requested.
     ///
     /// Multiple closures can be registered and they will be called in order of
     /// their registration. If a closure returns `Err` then no further closures
     /// will be called and the spawn operation will immediately return with a
     /// failure.
     ///
     /// # Notes and Safety
     ///
     /// This closure will be run in the context of the child process after a
     /// `fork`. This primarily means that any modifications made to memory on
     /// behalf of this closure will **not** be visible to the parent process.
     /// This is often a very constrained environment where normal operations
     /// like `malloc` or acquiring a mutex are not guaranteed to work (due to
     /// other threads perhaps still running when the `fork` was run).
     ///
     /// This also means that all resources such as file descriptors and
     /// memory-mapped regions got duplicated. It is your responsibility to make
     /// sure that the closure does not violate library invariants by making
     /// invalid use of these duplicates.
     ///
     /// When this closure is run, aspects such as the stdio file descriptors and
     /// working directory have successfully been changed, so output to these
     /// locations may not appear where intended.
     #[stable(feature = "process_pre_exec", since = "1.34.0")]
     unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
     where
         F: FnMut() -> io::Result<()> + Send + Sync + 'static;

     /// Schedules a closure to be run just before the `exec` function is
     /// invoked.
     ///
     /// This method is stable and usable, but it should be unsafe. To fix
     /// that, it got deprecated in favor of the unsafe [`pre_exec`].
     ///
     /// [`pre_exec`]: CommandExt::pre_exec
     #[stable(feature = "process_exec", since = "1.15.0")]
     #[rustc_deprecated(since = "1.37.0", reason = "should be unsafe, use `pre_exec` instead")]
     fn before_exec<F>(&mut self, f: F) -> &mut process::Command
     where
         F: FnMut() -> io::Result<()> + Send + Sync + 'static,
     {
         unsafe { self.pre_exec(f) }
     }

     /// Performs all the required setup by this `Command`, followed by calling
     /// the `execvp` syscall.
     ///
     /// On success this function will not return, and otherwise it will return
     /// an error indicating why the exec (or another part of the setup of the
     /// `Command`) failed.
     ///
     /// `exec` not returning has the same implications as calling
     /// [`process::exit`] – no destructors on the current stack or any other
     /// thread’s stack will be run. Therefore, it is recommended to only call
     /// `exec` at a point where it is fine to not run any destructors. Note,
     /// that the `execvp` syscall independently guarantees that all memory is
     /// freed and all file descriptors with the `CLOEXEC` option (set by default
     /// on all file descriptors opened by the standard library) are closed.
     ///
     /// This function, unlike `spawn`, will **not** `fork` the process to create
     /// a new child. Like spawn, however, the default behavior for the stdio
     /// descriptors will be to inherited from the current process.
     ///
     /// # Notes
     ///
     /// The process may be in a "broken state" if this function returns in
     /// error. For example the working directory, environment variables, signal
     /// handling settings, various user/group information, or aspects of stdio
     /// file descriptors may have changed. If a "transactional spawn" is
     /// required to gracefully handle errors it is recommended to use the
     /// cross-platform `spawn` instead.
     #[stable(feature = "process_exec2", since = "1.9.0")]
     fn exec(&mut self) -> io::Error;

     /// Set executable argument
     ///
     /// Set the first process argument, `argv[0]`, to something other than the
     /// default executable path.
     #[stable(feature = "process_set_argv0", since = "1.45.0")]
     fn arg0<S>(&mut self, arg: S) -> &mut process::Command
     where
         S: AsRef<OsStr>;
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl CommandExt for process::Command {
     fn uid(&mut self, id: u32) -> &mut process::Command {
         self.as_inner_mut().uid(id);
         self
     }

     fn gid(&mut self, id: u32) -> &mut process::Command {
         self.as_inner_mut().gid(id);
         self
     }

     unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
     where
         F: FnMut() -> io::Result<()> + Send + Sync + 'static,
     {
         self.as_inner_mut().pre_exec(Box::new(f));
         self
     }

     fn exec(&mut self) -> io::Error {
         self.as_inner_mut().exec(sys::process::Stdio::Inherit)
     }

     fn arg0<S>(&mut self, arg: S) -> &mut process::Command
     where
         S: AsRef<OsStr>,
     {
         self.as_inner_mut().set_arg_0(arg.as_ref());
         self
     }
 }

 /// Unix-specific extensions to [`process::ExitStatus`].
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait ExitStatusExt {
     /// Creates a new `ExitStatus` from the raw underlying `i32` return value of
     /// a process.
     #[stable(feature = "exit_status_from", since = "1.12.0")]
     fn from_raw(raw: i32) -> Self;

     /// If the process was terminated by a signal, returns that signal.
     #[stable(feature = "rust1", since = "1.0.0")]
     fn signal(&self) -> Option<i32>;
 }

 #[stable(feature = "rust1", since = "1.0.0")]
 impl ExitStatusExt for process::ExitStatus {
     fn from_raw(raw: i32) -> Self {
         process::ExitStatus::from_inner(From::from(raw))
     }

     fn signal(&self) -> Option<i32> {
         self.as_inner().signal()
     }
 }

 #[stable(feature = "process_extensions", since = "1.2.0")]
 impl FromRawFd for process::Stdio {
     unsafe fn from_raw_fd(fd: RawFd) -> process::Stdio {
         let fd = sys::fd::FileDesc::new(fd);
         let io = sys::process::Stdio::Fd(fd);
         process::Stdio::from_inner(io)
     }
 }

 #[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawFd for process::ChildStdin {
     fn as_raw_fd(&self) -> RawFd {
         self.as_inner().fd().raw()
     }
 }

 #[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawFd for process::ChildStdout {
     fn as_raw_fd(&self) -> RawFd {
         self.as_inner().fd().raw()
     }
 }

 #[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawFd for process::ChildStderr {
     fn as_raw_fd(&self) -> RawFd {
         self.as_inner().fd().raw()
     }
 }

 #[stable(feature = "into_raw_os", since = "1.4.0")]
 impl IntoRawFd for process::ChildStdin {
     fn into_raw_fd(self) -> RawFd {
         self.into_inner().into_fd().into_raw()
     }
 }

 #[stable(feature = "into_raw_os", since = "1.4.0")]
 impl IntoRawFd for process::ChildStdout {
     fn into_raw_fd(self) -> RawFd {
         self.into_inner().into_fd().into_raw()
     }
 }

 #[stable(feature = "into_raw_os", since = "1.4.0")]
 impl IntoRawFd for process::ChildStderr {
     fn into_raw_fd(self) -> RawFd {
         self.into_inner().into_fd().into_raw()
     }
 }

 /// Returns the OS-assigned process identifier associated with this process's parent.
 #[stable(feature = "unix_ppid", since = "1.27.0")]
 pub fn parent_id() -> u32 {
     crate::sys::os::getppid()
 }
	//! Unix-specific extensions to primitives in the `std::process` module.

	#![stable(feature = "rust1", since = "1.0.0")]

	use crate::ffi::OsStr;
	use crate::io;
	use crate::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
	use crate::process;
	use crate::sys;
	use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};

	/// Unix-specific extensions to the [`process::Command`] builder.
	#[stable(feature = "rust1", since = "1.0.0")]
	pub trait CommandExt {
	/// Sets the child process's user ID. This translates to a
	/// `setuid` call in the child process. Failure in the `setuid`
	/// call will cause the spawn to fail.
	#[stable(feature = "rust1", since = "1.0.0")]
	fn uid(&mut self, id: u32) -> &mut process::Command;

	/// Similar to `uid`, but sets the group ID of the child process. This has
	/// the same semantics as the `uid` field.
	#[stable(feature = "rust1", since = "1.0.0")]
	fn gid(&mut self, id: u32) -> &mut process::Command;

	/// Schedules a closure to be run just before the `exec` function is
	/// invoked.
	///
	/// The closure is allowed to return an I/O error whose OS error code will
	/// be communicated back to the parent and returned as an error from when
	/// the spawn was requested.
	///
	/// Multiple closures can be registered and they will be called in order of
	/// their registration. If a closure returns `Err` then no further closures
	/// will be called and the spawn operation will immediately return with a
	/// failure.
	///
	/// # Notes and Safety
	///
	/// This closure will be run in the context of the child process after a
	/// `fork`. This primarily means that any modifications made to memory on
	/// behalf of this closure will not be visible to the parent process.
	/// This is often a very constrained environment where normal operations
	/// like `malloc` or acquiring a mutex are not guaranteed to work (due to
	/// other threads perhaps still running when the `fork` was run).
	///
	/// This also means that all resources such as file descriptors and
	/// memory-mapped regions got duplicated. It is your responsibility to make
	/// sure that the closure does not violate library invariants by making
	/// invalid use of these duplicates.
	///
	/// When this closure is run, aspects such as the stdio file descriptors and
	/// working directory have successfully been changed, so output to these
	/// locations may not appear where intended.
	#[stable(feature = "process_pre_exec", since = "1.34.0")]
	unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
	where
	F: FnMut() -> io::Result<()> + Send + Sync + 'static;

	/// Schedules a closure to be run just before the `exec` function is
	/// invoked.
	///
	/// This method is stable and usable, but it should be unsafe. To fix
	/// that, it got deprecated in favor of the unsafe [`pre_exec`].
	///
	/// [`pre_exec`]: CommandExt::pre_exec
	#[stable(feature = "process_exec", since = "1.15.0")]
	#[rustc_deprecated(since = "1.37.0", reason = "should be unsafe, use `pre_exec` instead")]
	fn before_exec<F>(&mut self, f: F) -> &mut process::Command
	where
	F: FnMut() -> io::Result<()> + Send + Sync + 'static,
	{
	unsafe { self.pre_exec(f) }
	}

	/// Performs all the required setup by this `Command`, followed by calling
	/// the `execvp` syscall.
	///
	/// On success this function will not return, and otherwise it will return
	/// an error indicating why the exec (or another part of the setup of the
	/// `Command`) failed.
	///
	/// `exec` not returning has the same implications as calling
	/// [`process::exit`] – no destructors on the current stack or any other
	/// thread’s stack will be run. Therefore, it is recommended to only call
	/// `exec` at a point where it is fine to not run any destructors. Note,
	/// that the `execvp` syscall independently guarantees that all memory is
	/// freed and all file descriptors with the `CLOEXEC` option (set by default
	/// on all file descriptors opened by the standard library) are closed.
	///
	/// This function, unlike `spawn`, will not `fork` the process to create
	/// a new child. Like spawn, however, the default behavior for the stdio
	/// descriptors will be to inherited from the current process.
	///
	/// # Notes
	///
	/// The process may be in a "broken state" if this function returns in
	/// error. For example the working directory, environment variables, signal
	/// handling settings, various user/group information, or aspects of stdio
	/// file descriptors may have changed. If a "transactional spawn" is
	/// required to gracefully handle errors it is recommended to use the
	/// cross-platform `spawn` instead.
	#[stable(feature = "process_exec2", since = "1.9.0")]
	fn exec(&mut self) -> io::Error;

	/// Set executable argument
	///
	/// Set the first process argument, `argv[0]`, to something other than the
	/// default executable path.
	#[stable(feature = "process_set_argv0", since = "1.45.0")]
	fn arg0<S>(&mut self, arg: S) -> &mut process::Command
	where
	S: AsRef<OsStr>;
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl CommandExt for process::Command {
	fn uid(&mut self, id: u32) -> &mut process::Command {
	self.as_inner_mut().uid(id);
	self
	}

	fn gid(&mut self, id: u32) -> &mut process::Command {
	self.as_inner_mut().gid(id);
	self
	}

	unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
	where
	F: FnMut() -> io::Result<()> + Send + Sync + 'static,
	{
	self.as_inner_mut().pre_exec(Box::new(f));
	self
	}

	fn exec(&mut self) -> io::Error {
	self.as_inner_mut().exec(sys::process::Stdio::Inherit)
	}

	fn arg0<S>(&mut self, arg: S) -> &mut process::Command
	where
	S: AsRef<OsStr>,
	{
	self.as_inner_mut().set_arg_0(arg.as_ref());
	self
	}
	}

	/// Unix-specific extensions to [`process::ExitStatus`].
	#[stable(feature = "rust1", since = "1.0.0")]
	pub trait ExitStatusExt {
	/// Creates a new `ExitStatus` from the raw underlying `i32` return value of
	/// a process.
	#[stable(feature = "exit_status_from", since = "1.12.0")]
	fn from_raw(raw: i32) -> Self;

	/// If the process was terminated by a signal, returns that signal.
	#[stable(feature = "rust1", since = "1.0.0")]
	fn signal(&self) -> Option<i32>;
	}

	#[stable(feature = "rust1", since = "1.0.0")]
	impl ExitStatusExt for process::ExitStatus {
	fn from_raw(raw: i32) -> Self {
	process::ExitStatus::from_inner(From::from(raw))
	}

	fn signal(&self) -> Option<i32> {
	self.as_inner().signal()
	}
	}

	#[stable(feature = "process_extensions", since = "1.2.0")]
	impl FromRawFd for process::Stdio {
	unsafe fn from_raw_fd(fd: RawFd) -> process::Stdio {
	let fd = sys::fd::FileDesc::new(fd);
	let io = sys::process::Stdio::Fd(fd);
	process::Stdio::from_inner(io)
	}
	}

	#[stable(feature = "process_extensions", since = "1.2.0")]
	impl AsRawFd for process::ChildStdin {
	fn as_raw_fd(&self) -> RawFd {
	self.as_inner().fd().raw()
	}
	}

	#[stable(feature = "process_extensions", since = "1.2.0")]
	impl AsRawFd for process::ChildStdout {
	fn as_raw_fd(&self) -> RawFd {
	self.as_inner().fd().raw()
	}
	}

	#[stable(feature = "process_extensions", since = "1.2.0")]
	impl AsRawFd for process::ChildStderr {
	fn as_raw_fd(&self) -> RawFd {
	self.as_inner().fd().raw()
	}
	}

	#[stable(feature = "into_raw_os", since = "1.4.0")]
	impl IntoRawFd for process::ChildStdin {
	fn into_raw_fd(self) -> RawFd {
	self.into_inner().into_fd().into_raw()
	}
	}

	#[stable(feature = "into_raw_os", since = "1.4.0")]
	impl IntoRawFd for process::ChildStdout {
	fn into_raw_fd(self) -> RawFd {
	self.into_inner().into_fd().into_raw()
	}
	}

	#[stable(feature = "into_raw_os", since = "1.4.0")]
	impl IntoRawFd for process::ChildStderr {
	fn into_raw_fd(self) -> RawFd {
	self.into_inner().into_fd().into_raw()
	}
	}

	/// Returns the OS-assigned process identifier associated with this process's parent.
	#[stable(feature = "unix_ppid", since = "1.27.0")]
	pub fn parent_id() -> u32 {
	crate::sys::os::getppid()
	}