From 68e983fcf7226c2e17b1dd568e566b02989efec5 Mon Sep 17 00:00:00 2001 From: Tobias Bucher Date: Fri, 17 Jan 2025 16:55:10 +0100 Subject: [PATCH 1/2] Move `std::io::pipe` code into its own file --- library/std/src/io/mod.rs | 258 +------------------------------ library/std/src/io/pipe.rs | 256 ++++++++++++++++++++++++++++++ library/std/src/io/pipe/tests.rs | 18 +++ library/std/src/io/tests.rs | 17 -- 4 files changed, 277 insertions(+), 272 deletions(-) create mode 100644 library/std/src/io/pipe.rs create mode 100644 library/std/src/io/pipe/tests.rs diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs index 1fa13e95e6872..cfd03b8e3d6d0 100644 --- a/library/std/src/io/mod.rs +++ b/library/std/src/io/mod.rs @@ -310,6 +310,8 @@ pub use self::error::RawOsError; pub use self::error::SimpleMessage; #[unstable(feature = "io_const_error", issue = "133448")] pub use self::error::const_error; +#[unstable(feature = "anonymous_pipe", issue = "127154")] +pub use self::pipe::{PipeReader, PipeWriter, pipe}; #[stable(feature = "is_terminal", since = "1.70.0")] pub use self::stdio::IsTerminal; pub(crate) use self::stdio::attempt_print_to_stderr; @@ -330,7 +332,6 @@ pub use self::{ }; use crate::mem::take; use crate::ops::{Deref, DerefMut}; -use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner}; use crate::{cmp, fmt, slice, str, sys}; mod buffered; @@ -338,6 +339,7 @@ pub(crate) mod copy; mod cursor; mod error; mod impls; +mod pipe; pub mod prelude; mod stdio; mod util; @@ -3251,257 +3253,3 @@ impl Iterator for Lines { } } } - -/// Create an anonymous pipe that is close-on-exec and blocking. -/// -/// # Behavior -/// -/// A pipe is a one-way data channel provided by the OS, which works across processes. A pipe is -/// typically used to communicate between two or more separate processes, as there are better, -/// faster ways to communicate within a single process. -/// -/// In particular: -/// -/// * A read on a [`PipeReader`] blocks until the pipe is non-empty. -/// * A write on a [`PipeWriter`] blocks when the pipe is full. -/// * When all copies of a [`PipeWriter`] are closed, a read on the corresponding [`PipeReader`] -/// returns EOF. -/// * [`PipeWriter`] can be shared, and multiple processes or threads can write to it at once, but -/// writes (above a target-specific threshold) may have their data interleaved. -/// * [`PipeReader`] can be shared, and multiple processes or threads can read it at once. Any -/// given byte will only get consumed by one reader. There are no guarantees about data -/// interleaving. -/// * Portable applications cannot assume any atomicity of messages larger than a single byte. -/// -/// # Capacity -/// -/// Pipe capacity is platform dependent. To quote the Linux [man page]: -/// -/// > Different implementations have different limits for the pipe capacity. Applications should -/// > not rely on a particular capacity: an application should be designed so that a reading process -/// > consumes data as soon as it is available, so that a writing process does not remain blocked. -/// -/// # Examples -/// -/// ```no_run -/// #![feature(anonymous_pipe)] -/// # #[cfg(miri)] fn main() {} -/// # #[cfg(not(miri))] -/// # fn main() -> std::io::Result<()> { -/// # use std::process::Command; -/// # use std::io::{Read, Write}; -/// let (ping_rx, mut ping_tx) = std::io::pipe()?; -/// let (mut pong_rx, pong_tx) = std::io::pipe()?; -/// -/// // Spawn a process that echoes its input. -/// let mut echo_server = Command::new("cat").stdin(ping_rx).stdout(pong_tx).spawn()?; -/// -/// ping_tx.write_all(b"hello")?; -/// // Close to unblock echo_server's reader. -/// drop(ping_tx); -/// -/// let mut buf = String::new(); -/// // Block until echo_server's writer is closed. -/// pong_rx.read_to_string(&mut buf)?; -/// assert_eq!(&buf, "hello"); -/// -/// echo_server.wait()?; -/// # Ok(()) -/// # } -/// ``` -/// [man page]: https://man7.org/linux/man-pages/man7/pipe.7.html -#[unstable(feature = "anonymous_pipe", issue = "127154")] -#[inline] -pub fn pipe() -> Result<(PipeReader, PipeWriter)> { - pipe_inner().map(|(reader, writer)| (PipeReader(reader), PipeWriter(writer))) -} - -/// Read end of an anonymous pipe. -#[unstable(feature = "anonymous_pipe", issue = "127154")] -#[derive(Debug)] -pub struct PipeReader(pub(crate) AnonPipe); - -/// Write end of an anonymous pipe. -#[unstable(feature = "anonymous_pipe", issue = "127154")] -#[derive(Debug)] -pub struct PipeWriter(pub(crate) AnonPipe); - -impl PipeReader { - /// Create a new [`PipeReader`] instance that shares the same underlying file description. - /// - /// # Examples - /// - /// ```no_run - /// #![feature(anonymous_pipe)] - /// # #[cfg(miri)] fn main() {} - /// # #[cfg(not(miri))] - /// # fn main() -> std::io::Result<()> { - /// # use std::fs; - /// # use std::io::Write; - /// # use std::process::Command; - /// const NUM_SLOT: u8 = 2; - /// const NUM_PROC: u8 = 5; - /// const OUTPUT: &str = "work.txt"; - /// - /// let mut jobs = vec![]; - /// let (reader, mut writer) = std::io::pipe()?; - /// - /// // Write NUM_SLOT characters the pipe. - /// writer.write_all(&[b'|'; NUM_SLOT as usize])?; - /// - /// // Spawn several processes that read a character from the pipe, do some work, then - /// // write back to the pipe. When the pipe is empty, the processes block, so only - /// // NUM_SLOT processes can be working at any given time. - /// for _ in 0..NUM_PROC { - /// jobs.push( - /// Command::new("bash") - /// .args(["-c", - /// &format!( - /// "read -n 1\n\ - /// echo -n 'x' >> '{OUTPUT}'\n\ - /// echo -n '|'", - /// ), - /// ]) - /// .stdin(reader.try_clone()?) - /// .stdout(writer.try_clone()?) - /// .spawn()?, - /// ); - /// } - /// - /// // Wait for all jobs to finish. - /// for mut job in jobs { - /// job.wait()?; - /// } - /// - /// // Check our work and clean up. - /// let xs = fs::read_to_string(OUTPUT)?; - /// fs::remove_file(OUTPUT)?; - /// assert_eq!(xs, "x".repeat(NUM_PROC.into())); - /// # Ok(()) - /// # } - /// ``` - #[unstable(feature = "anonymous_pipe", issue = "127154")] - pub fn try_clone(&self) -> Result { - self.0.try_clone().map(Self) - } -} - -impl PipeWriter { - /// Create a new [`PipeWriter`] instance that shares the same underlying file description. - /// - /// # Examples - /// - /// ```no_run - /// #![feature(anonymous_pipe)] - /// # #[cfg(miri)] fn main() {} - /// # #[cfg(not(miri))] - /// # fn main() -> std::io::Result<()> { - /// # use std::process::Command; - /// # use std::io::Read; - /// let (mut reader, writer) = std::io::pipe()?; - /// - /// // Spawn a process that writes to stdout and stderr. - /// let mut peer = Command::new("bash") - /// .args([ - /// "-c", - /// "echo -n foo\n\ - /// echo -n bar >&2" - /// ]) - /// .stdout(writer.try_clone()?) - /// .stderr(writer) - /// .spawn()?; - /// - /// // Read and check the result. - /// let mut msg = String::new(); - /// reader.read_to_string(&mut msg)?; - /// assert_eq!(&msg, "foobar"); - /// - /// peer.wait()?; - /// # Ok(()) - /// # } - /// ``` - #[unstable(feature = "anonymous_pipe", issue = "127154")] - pub fn try_clone(&self) -> Result { - self.0.try_clone().map(Self) - } -} - -#[unstable(feature = "anonymous_pipe", issue = "127154")] -impl Read for &PipeReader { - fn read(&mut self, buf: &mut [u8]) -> Result { - self.0.read(buf) - } - fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result { - self.0.read_vectored(bufs) - } - #[inline] - fn is_read_vectored(&self) -> bool { - self.0.is_read_vectored() - } - fn read_to_end(&mut self, buf: &mut Vec) -> Result { - self.0.read_to_end(buf) - } - fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<()> { - self.0.read_buf(buf) - } -} - -#[unstable(feature = "anonymous_pipe", issue = "127154")] -impl Read for PipeReader { - fn read(&mut self, buf: &mut [u8]) -> Result { - self.0.read(buf) - } - fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result { - self.0.read_vectored(bufs) - } - #[inline] - fn is_read_vectored(&self) -> bool { - self.0.is_read_vectored() - } - fn read_to_end(&mut self, buf: &mut Vec) -> Result { - self.0.read_to_end(buf) - } - fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<()> { - self.0.read_buf(buf) - } -} - -#[unstable(feature = "anonymous_pipe", issue = "127154")] -impl Write for &PipeWriter { - fn write(&mut self, buf: &[u8]) -> Result { - self.0.write(buf) - } - #[inline] - fn flush(&mut self) -> Result<()> { - Ok(()) - } - - fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result { - self.0.write_vectored(bufs) - } - - #[inline] - fn is_write_vectored(&self) -> bool { - self.0.is_write_vectored() - } -} - -#[unstable(feature = "anonymous_pipe", issue = "127154")] -impl Write for PipeWriter { - fn write(&mut self, buf: &[u8]) -> Result { - self.0.write(buf) - } - #[inline] - fn flush(&mut self) -> Result<()> { - Ok(()) - } - - fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result { - self.0.write_vectored(bufs) - } - - #[inline] - fn is_write_vectored(&self) -> bool { - self.0.is_write_vectored() - } -} diff --git a/library/std/src/io/pipe.rs b/library/std/src/io/pipe.rs new file mode 100644 index 0000000000000..cd33294b2710d --- /dev/null +++ b/library/std/src/io/pipe.rs @@ -0,0 +1,256 @@ +use crate::io; +use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner}; + +/// Create an anonymous pipe that is close-on-exec and blocking. +/// +/// # Behavior +/// +/// A pipe is a one-way data channel provided by the OS, which works across processes. A pipe is +/// typically used to communicate between two or more separate processes, as there are better, +/// faster ways to communicate within a single process. +/// +/// In particular: +/// +/// * A read on a [`PipeReader`] blocks until the pipe is non-empty. +/// * A write on a [`PipeWriter`] blocks when the pipe is full. +/// * When all copies of a [`PipeWriter`] are closed, a read on the corresponding [`PipeReader`] +/// returns EOF. +/// * [`PipeWriter`] can be shared, and multiple processes or threads can write to it at once, but +/// writes (above a target-specific threshold) may have their data interleaved. +/// * [`PipeReader`] can be shared, and multiple processes or threads can read it at once. Any +/// given byte will only get consumed by one reader. There are no guarantees about data +/// interleaving. +/// * Portable applications cannot assume any atomicity of messages larger than a single byte. +/// +/// # Capacity +/// +/// Pipe capacity is platform dependent. To quote the Linux [man page]: +/// +/// > Different implementations have different limits for the pipe capacity. Applications should +/// > not rely on a particular capacity: an application should be designed so that a reading process +/// > consumes data as soon as it is available, so that a writing process does not remain blocked. +/// +/// # Examples +/// +/// ```no_run +/// #![feature(anonymous_pipe)] +/// # #[cfg(miri)] fn main() {} +/// # #[cfg(not(miri))] +/// # fn main() -> std::io::Result<()> { +/// # use std::process::Command; +/// # use std::io::{Read, Write}; +/// let (ping_rx, mut ping_tx) = std::io::pipe()?; +/// let (mut pong_rx, pong_tx) = std::io::pipe()?; +/// +/// // Spawn a process that echoes its input. +/// let mut echo_server = Command::new("cat").stdin(ping_rx).stdout(pong_tx).spawn()?; +/// +/// ping_tx.write_all(b"hello")?; +/// // Close to unblock echo_server's reader. +/// drop(ping_tx); +/// +/// let mut buf = String::new(); +/// // Block until echo_server's writer is closed. +/// pong_rx.read_to_string(&mut buf)?; +/// assert_eq!(&buf, "hello"); +/// +/// echo_server.wait()?; +/// # Ok(()) +/// # } +/// ``` +/// [man page]: https://man7.org/linux/man-pages/man7/pipe.7.html +#[unstable(feature = "anonymous_pipe", issue = "127154")] +#[inline] +pub fn pipe() -> io::Result<(PipeReader, PipeWriter)> { + pipe_inner().map(|(reader, writer)| (PipeReader(reader), PipeWriter(writer))) +} + +/// Read end of an anonymous pipe. +#[unstable(feature = "anonymous_pipe", issue = "127154")] +#[derive(Debug)] +pub struct PipeReader(pub(crate) AnonPipe); + +/// Write end of an anonymous pipe. +#[unstable(feature = "anonymous_pipe", issue = "127154")] +#[derive(Debug)] +pub struct PipeWriter(pub(crate) AnonPipe); + +impl PipeReader { + /// Create a new [`PipeReader`] instance that shares the same underlying file description. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(anonymous_pipe)] + /// # #[cfg(miri)] fn main() {} + /// # #[cfg(not(miri))] + /// # fn main() -> std::io::Result<()> { + /// # use std::fs; + /// # use std::io::Write; + /// # use std::process::Command; + /// const NUM_SLOT: u8 = 2; + /// const NUM_PROC: u8 = 5; + /// const OUTPUT: &str = "work.txt"; + /// + /// let mut jobs = vec![]; + /// let (reader, mut writer) = std::io::pipe()?; + /// + /// // Write NUM_SLOT characters the pipe. + /// writer.write_all(&[b'|'; NUM_SLOT as usize])?; + /// + /// // Spawn several processes that read a character from the pipe, do some work, then + /// // write back to the pipe. When the pipe is empty, the processes block, so only + /// // NUM_SLOT processes can be working at any given time. + /// for _ in 0..NUM_PROC { + /// jobs.push( + /// Command::new("bash") + /// .args(["-c", + /// &format!( + /// "read -n 1\n\ + /// echo -n 'x' >> '{OUTPUT}'\n\ + /// echo -n '|'", + /// ), + /// ]) + /// .stdin(reader.try_clone()?) + /// .stdout(writer.try_clone()?) + /// .spawn()?, + /// ); + /// } + /// + /// // Wait for all jobs to finish. + /// for mut job in jobs { + /// job.wait()?; + /// } + /// + /// // Check our work and clean up. + /// let xs = fs::read_to_string(OUTPUT)?; + /// fs::remove_file(OUTPUT)?; + /// assert_eq!(xs, "x".repeat(NUM_PROC.into())); + /// # Ok(()) + /// # } + /// ``` + #[unstable(feature = "anonymous_pipe", issue = "127154")] + pub fn try_clone(&self) -> io::Result { + self.0.try_clone().map(Self) + } +} + +impl PipeWriter { + /// Create a new [`PipeWriter`] instance that shares the same underlying file description. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(anonymous_pipe)] + /// # #[cfg(miri)] fn main() {} + /// # #[cfg(not(miri))] + /// # fn main() -> std::io::Result<()> { + /// # use std::process::Command; + /// # use std::io::Read; + /// let (mut reader, writer) = std::io::pipe()?; + /// + /// // Spawn a process that writes to stdout and stderr. + /// let mut peer = Command::new("bash") + /// .args([ + /// "-c", + /// "echo -n foo\n\ + /// echo -n bar >&2" + /// ]) + /// .stdout(writer.try_clone()?) + /// .stderr(writer) + /// .spawn()?; + /// + /// // Read and check the result. + /// let mut msg = String::new(); + /// reader.read_to_string(&mut msg)?; + /// assert_eq!(&msg, "foobar"); + /// + /// peer.wait()?; + /// # Ok(()) + /// # } + /// ``` + #[unstable(feature = "anonymous_pipe", issue = "127154")] + pub fn try_clone(&self) -> io::Result { + self.0.try_clone().map(Self) + } +} + +#[unstable(feature = "anonymous_pipe", issue = "127154")] +impl io::Read for &PipeReader { + fn read(&mut self, buf: &mut [u8]) -> io::Result { + self.0.read(buf) + } + fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result { + self.0.read_vectored(bufs) + } + #[inline] + fn is_read_vectored(&self) -> bool { + self.0.is_read_vectored() + } + fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { + self.0.read_to_end(buf) + } + fn read_buf(&mut self, buf: io::BorrowedCursor<'_>) -> io::Result<()> { + self.0.read_buf(buf) + } +} + +#[unstable(feature = "anonymous_pipe", issue = "127154")] +impl io::Read for PipeReader { + fn read(&mut self, buf: &mut [u8]) -> io::Result { + self.0.read(buf) + } + fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result { + self.0.read_vectored(bufs) + } + #[inline] + fn is_read_vectored(&self) -> bool { + self.0.is_read_vectored() + } + fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { + self.0.read_to_end(buf) + } + fn read_buf(&mut self, buf: io::BorrowedCursor<'_>) -> io::Result<()> { + self.0.read_buf(buf) + } +} + +#[unstable(feature = "anonymous_pipe", issue = "127154")] +impl io::Write for &PipeWriter { + fn write(&mut self, buf: &[u8]) -> io::Result { + self.0.write(buf) + } + #[inline] + fn flush(&mut self) -> io::Result<()> { + Ok(()) + } + + fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result { + self.0.write_vectored(bufs) + } + + #[inline] + fn is_write_vectored(&self) -> bool { + self.0.is_write_vectored() + } +} + +#[unstable(feature = "anonymous_pipe", issue = "127154")] +impl io::Write for PipeWriter { + fn write(&mut self, buf: &[u8]) -> io::Result { + self.0.write(buf) + } + #[inline] + fn flush(&mut self) -> io::Result<()> { + Ok(()) + } + + fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result { + self.0.write_vectored(bufs) + } + + #[inline] + fn is_write_vectored(&self) -> bool { + self.0.is_write_vectored() + } +} diff --git a/library/std/src/io/pipe/tests.rs b/library/std/src/io/pipe/tests.rs new file mode 100644 index 0000000000000..c1f3f192ca2d7 --- /dev/null +++ b/library/std/src/io/pipe/tests.rs @@ -0,0 +1,18 @@ +use crate::io::{Read, Write, pipe}; + +#[test] +#[cfg(all(windows, unix, not(miri)))] +fn pipe_creation_clone_and_rw() { + let (rx, tx) = pipe().unwrap(); + + tx.try_clone().unwrap().write_all(b"12345").unwrap(); + drop(tx); + + let mut rx2 = rx.try_clone().unwrap(); + drop(rx); + + let mut s = String::new(); + rx2.read_to_string(&mut s).unwrap(); + drop(rx2); + assert_eq!(s, "12345"); +} diff --git a/library/std/src/io/tests.rs b/library/std/src/io/tests.rs index 226cc6011bcab..f64f034cce779 100644 --- a/library/std/src/io/tests.rs +++ b/library/std/src/io/tests.rs @@ -821,20 +821,3 @@ fn try_oom_error() { let io_err = io::Error::from(reserve_err); assert_eq!(io::ErrorKind::OutOfMemory, io_err.kind()); } - -#[test] -#[cfg(all(windows, unix, not(miri)))] -fn pipe_creation_clone_and_rw() { - let (rx, tx) = std::io::pipe().unwrap(); - - tx.try_clone().unwrap().write_all(b"12345").unwrap(); - drop(tx); - - let mut rx2 = rx.try_clone().unwrap(); - drop(rx); - - let mut s = String::new(); - rx2.read_to_string(&mut s).unwrap(); - drop(rx2); - assert_eq!(s, "12345"); -} From ad28cbb423b5ab203a502ecee30d630e54ea3498 Mon Sep 17 00:00:00 2001 From: Tobias Bucher Date: Fri, 17 Jan 2025 17:11:08 +0100 Subject: [PATCH 2/2] Update `std::io::{pipe, PipeReader, PipeWriter}` docs the new location Also create a section "Platform-specific behavior", don't hide required imports for code examples. --- library/std/src/io/pipe.rs | 36 ++++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/library/std/src/io/pipe.rs b/library/std/src/io/pipe.rs index cd33294b2710d..266c7bc96389b 100644 --- a/library/std/src/io/pipe.rs +++ b/library/std/src/io/pipe.rs @@ -1,7 +1,7 @@ use crate::io; use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner}; -/// Create an anonymous pipe that is close-on-exec and blocking. +/// Create an anonymous pipe. /// /// # Behavior /// @@ -22,6 +22,13 @@ use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner}; /// interleaving. /// * Portable applications cannot assume any atomicity of messages larger than a single byte. /// +/// # Platform-specific behavior +/// +/// This function currently corresponds to the `pipe` function on Unix and the +/// `CreatePipe` function on Windows. +/// +/// Note that this [may change in the future][changes]. +/// /// # Capacity /// /// Pipe capacity is platform dependent. To quote the Linux [man page]: @@ -37,10 +44,10 @@ use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner}; /// # #[cfg(miri)] fn main() {} /// # #[cfg(not(miri))] /// # fn main() -> std::io::Result<()> { -/// # use std::process::Command; -/// # use std::io::{Read, Write}; -/// let (ping_rx, mut ping_tx) = std::io::pipe()?; -/// let (mut pong_rx, pong_tx) = std::io::pipe()?; +/// use std::process::Command; +/// use std::io::{pipe, Read, Write}; +/// let (ping_rx, mut ping_tx) = pipe()?; +/// let (mut pong_rx, pong_tx) = pipe()?; /// /// // Spawn a process that echoes its input. /// let mut echo_server = Command::new("cat").stdin(ping_rx).stdout(pong_tx).spawn()?; @@ -58,6 +65,7 @@ use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner}; /// # Ok(()) /// # } /// ``` +/// [changes]: io#platform-specific-behavior /// [man page]: https://man7.org/linux/man-pages/man7/pipe.7.html #[unstable(feature = "anonymous_pipe", issue = "127154")] #[inline] @@ -85,15 +93,15 @@ impl PipeReader { /// # #[cfg(miri)] fn main() {} /// # #[cfg(not(miri))] /// # fn main() -> std::io::Result<()> { - /// # use std::fs; - /// # use std::io::Write; - /// # use std::process::Command; + /// use std::fs; + /// use std::io::{pipe, Write}; + /// use std::process::Command; /// const NUM_SLOT: u8 = 2; /// const NUM_PROC: u8 = 5; /// const OUTPUT: &str = "work.txt"; /// /// let mut jobs = vec![]; - /// let (reader, mut writer) = std::io::pipe()?; + /// let (reader, mut writer) = pipe()?; /// /// // Write NUM_SLOT characters the pipe. /// writer.write_all(&[b'|'; NUM_SLOT as usize])?; @@ -145,9 +153,9 @@ impl PipeWriter { /// # #[cfg(miri)] fn main() {} /// # #[cfg(not(miri))] /// # fn main() -> std::io::Result<()> { - /// # use std::process::Command; - /// # use std::io::Read; - /// let (mut reader, writer) = std::io::pipe()?; + /// use std::process::Command; + /// use std::io::{pipe, Read}; + /// let (mut reader, writer) = pipe()?; /// /// // Spawn a process that writes to stdout and stderr. /// let mut peer = Command::new("bash") @@ -224,11 +232,9 @@ impl io::Write for &PipeWriter { fn flush(&mut self) -> io::Result<()> { Ok(()) } - fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result { self.0.write_vectored(bufs) } - #[inline] fn is_write_vectored(&self) -> bool { self.0.is_write_vectored() @@ -244,11 +250,9 @@ impl io::Write for PipeWriter { fn flush(&mut self) -> io::Result<()> { Ok(()) } - fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result { self.0.write_vectored(bufs) } - #[inline] fn is_write_vectored(&self) -> bool { self.0.is_write_vectored()