1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647
//! Holds the std implementation of a process.
//!
//! All interactions are blocking, including the dropping of child processes (on *nix platforms).
//!
//! # Spawning an owned process
//!
//! ```no_run
//! use std::process::Command;
//! use pwner::Spawner;
//!
//! Command::new("ls").spawn_owned().expect("ls command failed to start");
//! ```
//!
//! # Reading from the process
//!
//! ```no_run
//! # fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
//! use std::io::Read;
//! use std::process::Command;
//! use pwner::Spawner;
//!
//! let mut child = Command::new("ls").spawn_owned()?;
//! let mut output = String::new();
//! child.read_to_string(&mut output)?;
//! # Ok(())
//! # }
//! ```
//!
//! # Writing to the process
//!
//! ```no_run
//! # fn wrapper() -> Result<(), Box<dyn std::error::Error>> {
//! use std::io::{Read, Write};
//! use std::process::Command;
//! use pwner::Spawner;
//!
//! let mut child = Command::new("cat").spawn_owned()?;
//! child.write_all(b"hello\n")?;
//!
//! let mut buffer = [0_u8; 10];
//! child.read(&mut buffer)?;
//! # Ok(())
//! # }
//! ```
//!
//! # Graceful dropping
//!
//! **Note:** Only available on *nix platforms.
//!
//! When the owned process gets dropped, [`Process`](crate::Process) will try to kill it gracefully
//! by sending a `SIGINT` and checking, without blocking, if the child has diesd. If the child is
//! still running, it will block for 2seconds. If the process still doesn't die, a `SIGTERM` is
//! sent and another chance is given, until finally a `SIGKILL` is sent.
/// Possible sources to read from
#[derive(Debug, Copy, Clone)]
pub enum ReadSource {
/// Read from the child's stdout
Stdout,
/// Read from the child's stderr
Stderr,
}
/// An implementation of [`Process`](crate::Process) that uses [`std::process`]
/// as the launcher.
///
/// All read and write operations are sync.
///
/// **Note:** On *nix platforms, the owned process will have 2 seconds between signals, which is a
/// blocking wait.
pub struct Duplex(Simplex, Output);
impl super::Spawner for std::process::Command {
type Output = Duplex;
fn spawn_owned(&mut self) -> std::io::Result<Self::Output> {
let mut process = self
.stdin(std::process::Stdio::piped())
.stdout(std::process::Stdio::piped())
.stderr(std::process::Stdio::piped())
.spawn()?;
// Panic:
// Because the pipes were set above, these will be present and `unwrap()` is safe
let stdin = process.stdin.take().unwrap();
let stdout = process.stdout.take().unwrap();
let stderr = process.stderr.take().unwrap();
Ok(Duplex(
Simplex(Some(ProcessImpl { process, stdin })),
Output {
read_source: ReadSource::Stdout,
stdout,
stderr,
},
))
}
}
impl super::Process for Duplex {}
impl Duplex {
/// Returns the OS-assigned process identifier associated with this child.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let mut command = Command::new("ls");
/// if let Ok(child) = command.spawn_owned() {
/// println!("Child's ID is {}", child.id());
/// } else {
/// println!("ls command didn't start");
/// }
/// ```
#[must_use]
pub fn id(&self) -> u32 {
self.0.id()
}
/// Choose which pipe to read form next.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::Read;
/// use std::process::Command;
/// use pwner::Spawner;
/// use pwner::process::ReadSource;
///
/// let mut child = Command::new("ls").spawn_owned().unwrap();
/// let mut buffer = [0_u8; 1024];
/// child.read_from(ReadSource::Stdout).read(&mut buffer).unwrap();
/// ```
pub fn read_from(&mut self, read_source: ReadSource) -> &mut Self {
self.1.read_from(read_source);
self
}
/// Waits for the child to exit completely, returning the status with which it exited, stdout,
/// and stderr.
///
/// The stdin handle to the child process, if any, will be closed before waiting. This helps
/// avoid deadlock: it ensures that the child does not block waiting for input from the parent,
/// while the parent waits for the child to exit.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use pwner::Spawner;
/// use std::io::{BufReader, Read};
/// use std::process::Command;
///
/// let child = Command::new("ls").spawn_owned().unwrap();
/// let (status, stdout, stderr) = child.wait().unwrap();
///
/// let mut buffer = String::new();
/// if status.success() {
/// let mut reader = BufReader::new(stdout);
/// reader.read_to_string(&mut buffer).unwrap();
/// } else {
/// let mut reader = BufReader::new(stderr);
/// reader.read_to_string(&mut buffer).unwrap();
/// }
/// ```
///
/// # Errors
///
/// Relays the error from [`std::process::Child::wait()`]
pub fn wait(
self,
) -> Result<
(
std::process::ExitStatus,
std::process::ChildStdout,
std::process::ChildStderr,
),
std::io::Error,
> {
let (mut child, _, stdout, stderr) = self.eject();
child.wait().map(|status| (status, stdout, stderr))
}
/// Decomposes the handle into mutable references to the pipes.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::{ Read, Write };
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let mut child = Command::new("cat").spawn_owned().unwrap();
/// let mut buffer = [0_u8; 1024];
/// let (stdin, stdout, _) = child.pipes();
///
/// stdin.write_all(b"hello\n").unwrap();
/// stdout.read(&mut buffer).unwrap();
/// ```
pub fn pipes(
&mut self,
) -> (
&mut std::process::ChildStdin,
&mut std::process::ChildStdout,
&mut std::process::ChildStderr,
) {
(self.0.stdin(), &mut self.1.stdout, &mut self.1.stderr)
}
/// Separates the process and its input from the output pipes. Ownership is retained by a
/// [`Simplex`] which still implements a graceful drop of the child process.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::{Read, Write};
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let child = Command::new("cat").spawn_owned().unwrap();
/// let (mut input_only_process, mut output) = child.decompose();
///
/// // Spawn printing thread
/// std::thread::spawn(move || {
/// let mut buffer = [0; 1024];
/// while let Ok(bytes) = output.read(&mut buffer) {
/// if let Ok(string) = std::str::from_utf8(&buffer[..bytes]) {
/// print!("{}", string);
/// }
/// }
/// });
///
/// // Interact normally with the child process
/// input_only_process.write_all(b"hello\n").unwrap();
/// ```
#[must_use]
pub fn decompose(self) -> (Simplex, Output) {
(self.0, self.1)
}
/// Completely releases the ownership of the child process. The raw underlying process and
/// pipes are returned and no wrapping function is applicable any longer.
///
/// **Note:** By ejecting the process, graceful drop will no longer be available.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::{ Read, Write };
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let mut child = Command::new("cat").spawn_owned().unwrap();
/// let mut buffer = [0_u8; 1024];
/// let (process, mut stdin, mut stdout, _) = child.eject();
///
/// stdin.write_all(b"hello\n").unwrap();
/// stdout.read(&mut buffer).unwrap();
///
/// // Graceful drop will not be executed for `child` as the ejected variable leaves scope here
/// ```
#[must_use]
pub fn eject(
self,
) -> (
std::process::Child,
std::process::ChildStdin,
std::process::ChildStdout,
std::process::ChildStderr,
) {
let (process, stdin) = self.0.eject();
let (stdout, stderr) = self.1.eject();
(process, stdin, stdout, stderr)
}
}
impl std::io::Write for Duplex {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
self.0.write(buf)
}
fn flush(&mut self) -> std::io::Result<()> {
self.0.flush()
}
}
impl std::io::Read for Duplex {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
self.1.read(buf)
}
}
/// An implementation of [`Process`](crate::Process) that is stripped from any output
/// pipes.
///
/// All write operations are sync.
///
/// # Examples
///
/// ```no_run
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let mut command = Command::new("ls");
/// if let Ok(child) = command.spawn_owned() {
/// let (input_only_process, _) = child.decompose();
/// } else {
/// println!("ls command didn't start");
/// }
/// ```
///
/// **Note:** On *nix platforms, the owned process will have 2 seconds between signals, which is a
/// blocking wait.
#[allow(clippy::module_name_repetitions)]
pub struct Simplex(Option<ProcessImpl>);
impl super::Process for Simplex {}
impl Simplex {
/// Returns the OS-assigned process identifier associated with this child.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let mut command = Command::new("ls");
/// if let Ok(child) = command.spawn_owned() {
/// let (process, _) = child.decompose();
/// println!("Child's ID is {}", process.id());
/// } else {
/// println!("ls command didn't start");
/// }
/// ```
#[must_use]
pub fn id(&self) -> u32 {
self.0
.as_ref()
.unwrap_or_else(|| unreachable!())
.process
.id()
}
fn stdin(&mut self) -> &mut std::process::ChildStdin {
// Panic:
// The `Option` will only be missing at the `Drop` site. While the instance is alive, it
// will always be present
&mut self.0.as_mut().unwrap().stdin
}
/// Waits for the child to exit completely, returning the status with which it exited.
///
/// The stdin handle to the child process, if any, will be closed before waiting. This helps
/// avoid deadlock: it ensures that the child does not block waiting for input from the parent,
/// while the parent waits for the child to exit.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use pwner::{process::ReadSource, Spawner};
/// use std::io::{BufReader, Read, Write};
/// use std::process::Command;
///
/// let (mut child, mut output) = Command::new("cat").spawn_owned().unwrap().decompose();
///
/// child.write_all(b"Hello\n").unwrap();
/// let status = child.wait().unwrap();
///
/// let mut buffer = String::new();
/// if status.success() {
/// output.read_from(ReadSource::Stdout);
/// } else {
/// output.read_from(ReadSource::Stderr);
/// }
/// let mut reader = BufReader::new(output);
/// reader.read_to_string(&mut buffer).unwrap();
/// ```
///
/// # Errors
///
/// Relays the error from [`std::process::Child::wait()`]
pub fn wait(self) -> Result<std::process::ExitStatus, std::io::Error> {
let (mut child, _) = self.eject();
child.wait()
}
/// Completely releases the ownership of the child process. The raw underlying process and
/// pipes are returned and no wrapping function is applicable any longer.
///
/// **Note:** By ejecting the process, graceful drop will no longer be available.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::{ Read, Write };
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let (child, mut output) = Command::new("cat").spawn_owned().unwrap().decompose();
/// let mut buffer = [0_u8; 1024];
/// let (process, mut stdin) = child.eject();
///
/// stdin.write_all(b"hello\n").unwrap();
/// output.read(&mut buffer).unwrap();
///
/// // Graceful drop will not be executed for `child` as the ejected variable leaves scope here
/// ```
#[must_use]
pub fn eject(mut self) -> (std::process::Child, std::process::ChildStdin) {
let process = self.0.take().unwrap_or_else(|| unreachable!());
(process.process, process.stdin)
}
}
impl std::ops::Drop for Simplex {
fn drop(&mut self) {
if let Some(process) = self.0.take() {
drop(process.shutdown());
}
}
}
impl std::io::Write for Simplex {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
// Panic:
// The `Option` will only be missing at the `Drop` site. While the instance is alive, it
// will always be present
self.0.as_mut().unwrap().stdin.write(buf)
}
fn flush(&mut self) -> std::io::Result<()> {
// Panic:
// The `Option` will only be missing at the `Drop` site. While the instance is alive, it
// will always be present
self.0.as_mut().unwrap().stdin.flush()
}
}
/// A readable handle for both the stdout and stderr of the child process.
pub struct Output {
read_source: ReadSource,
stdout: std::process::ChildStdout,
stderr: std::process::ChildStderr,
}
impl Output {
/// Choose which pipe to read form next.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::Read;
/// use std::process::Command;
/// use pwner::Spawner;
/// use pwner::process::ReadSource;
///
/// let (process, mut output) = Command::new("ls").spawn_owned().unwrap().decompose();
/// let mut buffer = [0_u8; 1024];
/// output.read_from(ReadSource::Stdout).read(&mut buffer).unwrap();
/// ```
pub fn read_from(&mut self, read_source: ReadSource) -> &mut Self {
self.read_source = read_source;
self
}
/// Decomposes the handle into mutable references to the pipes.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use std::io::{ Read, Write };
/// use std::process::Command;
/// use pwner::Spawner;
///
/// let (process, mut output) = Command::new("ls").spawn_owned().unwrap().decompose();
/// let mut buffer = [0_u8; 1024];
/// let (stdout, stderr) = output.pipes();
///
/// stdout.read(&mut buffer).unwrap();
/// ```
pub fn pipes(
&mut self,
) -> (
&mut std::process::ChildStdout,
&mut std::process::ChildStderr,
) {
(&mut self.stdout, &mut self.stderr)
}
/// Consumes this struct returning the containing pipes.
#[must_use]
pub fn eject(self) -> (std::process::ChildStdout, std::process::ChildStderr) {
(self.stdout, self.stderr)
}
}
impl std::io::Read for Output {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
match self.read_source {
ReadSource::Stdout => self.stdout.read(buf),
ReadSource::Stderr => self.stderr.read(buf),
}
}
}
struct ProcessImpl {
process: std::process::Child,
stdin: std::process::ChildStdin,
}
impl ProcessImpl {
// Allowed because we are already assuming *nix
#[allow(clippy::cast_possible_wrap)]
#[cfg(unix)]
pub fn pid(&self) -> nix::unistd::Pid {
nix::unistd::Pid::from_raw(self.process.id() as nix::libc::pid_t)
}
#[cfg(not(unix))]
fn shutdown(mut self) -> std::io::Result<std::process::ExitStatus> {
self.process.kill();
self.process.wait()
}
#[cfg(unix)]
fn shutdown(mut self) -> Result<std::process::ExitStatus, super::UnixIoError> {
use std::io::Write;
// Copy pid
let pid = self.pid();
// Close stdin
self.stdin.flush()?;
std::mem::drop(self.stdin);
if let Ok(status) = self.process.try_wait() {
if status.is_none() {
use nix::sys::{signal, wait};
use wait::WaitStatus::Exited;
let no_hang = Some(wait::WaitPidFlag::WNOHANG);
// Try SIGINT
signal::kill(pid, signal::SIGINT)?;
std::thread::sleep(std::time::Duration::from_secs(2));
if let Ok(Exited(_, _)) = wait::waitpid(pid, no_hang) {
} else {
// Try SIGTERM
signal::kill(pid, signal::SIGTERM)?;
std::thread::sleep(std::time::Duration::from_secs(2));
if let Ok(Exited(_, _)) = wait::waitpid(pid, no_hang) {
} else {
// Go for the kill
self.process.kill()?;
}
}
}
}
// Block until process is freed
self.process.wait().map_err(super::UnixIoError::from)
}
}
#[cfg(all(test, unix))]
mod test {
use crate::Spawner;
#[test]
fn read() {
use std::io::BufRead;
let child = std::process::Command::new("sh")
.arg("-c")
.arg("echo hello")
.spawn_owned()
.unwrap();
let mut output = String::new();
let mut reader = std::io::BufReader::new(child);
assert!(reader.read_line(&mut output).is_ok());
assert_eq!("hello\n", output);
}
#[test]
fn write() {
use std::io::{BufRead, Write};
let mut child = std::process::Command::new("cat").spawn_owned().unwrap();
assert!(child.write_all(b"hello\n").is_ok());
let mut output = String::new();
let mut reader = std::io::BufReader::new(child);
assert!(reader.read_line(&mut output).is_ok());
assert_eq!("hello\n", output);
}
#[test]
fn decompose() {
use std::io::{BufRead, Write};
let child = std::process::Command::new("cat").spawn_owned().unwrap();
let (mut child, output) = child.decompose();
assert!(child.write_all(b"hello\n").is_ok());
let mut buffer = String::new();
let mut reader = std::io::BufReader::new(output);
assert!(reader.read_line(&mut buffer).is_ok());
assert_eq!("hello\n", buffer);
}
#[test]
fn drop() {
let child = std::process::Command::new("ls").spawn_owned().unwrap();
let mut simplex = child.0;
assert!(simplex.0.take().unwrap().shutdown().is_err());
}
}