src/libstd/process.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Working with processes.
  12
  13 #![stable(feature = "process", since = "1.0.0")]
  14
  15 use prelude::v1::*;
  16 use io::prelude::*;
  17
  18 use ffi::OsStr;
  19 use fmt;
  20 use io;
  21 use path::Path;
  22 use str;
  23 use sys::pipe::AnonPipe;
  24 use sys::process as imp;
  25 use sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
  26 use thread::{self, JoinHandle};
  27
  28 /// Representation of a running or exited child process.
  29 ///
  30 /// This structure is used to represent and manage child processes. A child
  31 /// process is created via the `Command` struct, which configures the spawning
  32 /// process and can itself be constructed using a builder-style interface.
  33 ///
  34 /// # Examples
  35 ///
  36 /// ```should_panic
  37 /// use std::process::Command;
  38 ///
  39 /// let mut child = Command::new("/bin/cat")
  40 ///                         .arg("file.txt")
  41 ///                         .spawn()
  42 ///                         .unwrap_or_else(|e| { panic!("failed to execute child: {}", e) });
  43 ///
  44 /// let ecode = child.wait()
  45 ///                  .unwrap_or_else(|e| { panic!("failed to wait on child: {}", e) });
  46 ///
  47 /// assert!(ecode.success());
  48 /// ```
  49 ///
  50 /// # Note
  51 ///
  52 /// Take note that there is no implementation of
  53 /// [`Drop`](../../core/ops/trait.Drop.html) for child processes, so if you
  54 /// do not ensure the `Child` has exited then it will continue to run, even
  55 /// after the `Child` handle to the child process has gone out of scope.
  56 ///
  57 /// Calling `wait` (or other functions that wrap around it) will make the
  58 /// parent process wait until the child has actually exited before continuing.
  59 #[stable(feature = "process", since = "1.0.0")]
  60 pub struct Child {
  61     handle: imp::Process,
  62
  63     /// The handle for writing to the child's stdin, if it has been captured
  64     #[stable(feature = "process", since = "1.0.0")]
  65     pub stdin: Option<ChildStdin>,
  66
  67     /// The handle for reading from the child's stdout, if it has been captured
  68     #[stable(feature = "process", since = "1.0.0")]
  69     pub stdout: Option<ChildStdout>,
  70
  71     /// The handle for reading from the child's stderr, if it has been captured
  72     #[stable(feature = "process", since = "1.0.0")]
  73     pub stderr: Option<ChildStderr>,
  74 }
  75
  76 impl AsInner<imp::Process> for Child {
  77     fn as_inner(&self) -> &imp::Process { &self.handle }
  78 }
  79
  80 impl FromInner<(imp::Process, imp::StdioPipes)> for Child {
  81     fn from_inner((handle, io): (imp::Process, imp::StdioPipes)) -> Child {
  82         Child {
  83             handle: handle,
  84             stdin: io.stdin.map(ChildStdin::from_inner),
  85             stdout: io.stdout.map(ChildStdout::from_inner),
  86             stderr: io.stderr.map(ChildStderr::from_inner),
  87         }
  88     }
  89 }
  90
  91 impl IntoInner<imp::Process> for Child {
  92     fn into_inner(self) -> imp::Process { self.handle }
  93 }
  94
  95 /// A handle to a child process's stdin
  96 #[stable(feature = "process", since = "1.0.0")]
  97 pub struct ChildStdin {
  98     inner: AnonPipe
  99 }
 100
 101 #[stable(feature = "process", since = "1.0.0")]
 102 impl Write for ChildStdin {
 103     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
 104         self.inner.write(buf)
 105     }
 106
 107     fn flush(&mut self) -> io::Result<()> {
 108         Ok(())
 109     }
 110 }
 111
 112 impl AsInner<AnonPipe> for ChildStdin {
 113     fn as_inner(&self) -> &AnonPipe { &self.inner }
 114 }
 115
 116 impl IntoInner<AnonPipe> for ChildStdin {
 117     fn into_inner(self) -> AnonPipe { self.inner }
 118 }
 119
 120 impl FromInner<AnonPipe> for ChildStdin {
 121     fn from_inner(pipe: AnonPipe) -> ChildStdin {
 122         ChildStdin { inner: pipe }
 123     }
 124 }
 125
 126 /// A handle to a child process's stdout
 127 #[stable(feature = "process", since = "1.0.0")]
 128 pub struct ChildStdout {
 129     inner: AnonPipe
 130 }
 131
 132 #[stable(feature = "process", since = "1.0.0")]
 133 impl Read for ChildStdout {
 134     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
 135         self.inner.read(buf)
 136     }
 137 }
 138
 139 impl AsInner<AnonPipe> for ChildStdout {
 140     fn as_inner(&self) -> &AnonPipe { &self.inner }
 141 }
 142
 143 impl IntoInner<AnonPipe> for ChildStdout {
 144     fn into_inner(self) -> AnonPipe { self.inner }
 145 }
 146
 147 impl FromInner<AnonPipe> for ChildStdout {
 148     fn from_inner(pipe: AnonPipe) -> ChildStdout {
 149         ChildStdout { inner: pipe }
 150     }
 151 }
 152
 153 /// A handle to a child process's stderr
 154 #[stable(feature = "process", since = "1.0.0")]
 155 pub struct ChildStderr {
 156     inner: AnonPipe
 157 }
 158
 159 #[stable(feature = "process", since = "1.0.0")]
 160 impl Read for ChildStderr {
 161     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
 162         self.inner.read(buf)
 163     }
 164 }
 165
 166 impl AsInner<AnonPipe> for ChildStderr {
 167     fn as_inner(&self) -> &AnonPipe { &self.inner }
 168 }
 169
 170 impl IntoInner<AnonPipe> for ChildStderr {
 171     fn into_inner(self) -> AnonPipe { self.inner }
 172 }
 173
 174 impl FromInner<AnonPipe> for ChildStderr {
 175     fn from_inner(pipe: AnonPipe) -> ChildStderr {
 176         ChildStderr { inner: pipe }
 177     }
 178 }
 179
 180 /// The `Command` type acts as a process builder, providing fine-grained control
 181 /// over how a new process should be spawned. A default configuration can be
 182 /// generated using `Command::new(program)`, where `program` gives a path to the
 183 /// program to be executed. Additional builder methods allow the configuration
 184 /// to be changed (for example, by adding arguments) prior to spawning:
 185 ///
 186 /// ```
 187 /// use std::process::Command;
 188 ///
 189 /// let output = Command::new("sh")
 190 ///                      .arg("-c")
 191 ///                      .arg("echo hello")
 192 ///                      .output()
 193 ///                      .unwrap_or_else(|e| { panic!("failed to execute process: {}", e) });
 194 /// let hello = output.stdout;
 195 /// ```
 196 #[stable(feature = "process", since = "1.0.0")]
 197 pub struct Command {
 198     inner: imp::Command,
 199 }
 200
 201 impl Command {
 202     /// Constructs a new `Command` for launching the program at
 203     /// path `program`, with the following default configuration:
 204     ///
 205     /// * No arguments to the program
 206     /// * Inherit the current process's environment
 207     /// * Inherit the current process's working directory
 208     /// * Inherit stdin/stdout/stderr for `spawn` or `status`, but create pipes for `output`
 209     ///
 210     /// Builder methods are provided to change these defaults and
 211     /// otherwise configure the process.
 212     #[stable(feature = "process", since = "1.0.0")]
 213     pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
 214         Command { inner: imp::Command::new(program.as_ref()) }
 215     }
 216
 217     /// Add an argument to pass to the program.
 218     #[stable(feature = "process", since = "1.0.0")]
 219     pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Command {
 220         self.inner.arg(arg.as_ref());
 221         self
 222     }
 223
 224     /// Add multiple arguments to pass to the program.
 225     #[stable(feature = "process", since = "1.0.0")]
 226     pub fn args<S: AsRef<OsStr>>(&mut self, args: &[S]) -> &mut Command {
 227         for arg in args {
 228             self.arg(arg.as_ref());
 229         }
 230         self
 231     }
 232
 233     /// Inserts or updates an environment variable mapping.
 234     ///
 235     /// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
 236     /// and case-sensitive on all other platforms.
 237     #[stable(feature = "process", since = "1.0.0")]
 238     pub fn env<K, V>(&mut self, key: K, val: V) -> &mut Command
 239         where K: AsRef<OsStr>, V: AsRef<OsStr>
 240     {
 241         self.inner.env(key.as_ref(), val.as_ref());
 242         self
 243     }
 244
 245     /// Removes an environment variable mapping.
 246     #[stable(feature = "process", since = "1.0.0")]
 247     pub fn env_remove<K: AsRef<OsStr>>(&mut self, key: K) -> &mut Command {
 248         self.inner.env_remove(key.as_ref());
 249         self
 250     }
 251
 252     /// Clears the entire environment map for the child process.
 253     #[stable(feature = "process", since = "1.0.0")]
 254     pub fn env_clear(&mut self) -> &mut Command {
 255         self.inner.env_clear();
 256         self
 257     }
 258
 259     /// Sets the working directory for the child process.
 260     #[stable(feature = "process", since = "1.0.0")]
 261     pub fn current_dir<P: AsRef<Path>>(&mut self, dir: P) -> &mut Command {
 262         self.inner.cwd(dir.as_ref().as_ref());
 263         self
 264     }
 265
 266     /// Configuration for the child process's stdin handle (file descriptor 0).
 267     #[stable(feature = "process", since = "1.0.0")]
 268     pub fn stdin(&mut self, cfg: Stdio) -> &mut Command {
 269         self.inner.stdin(cfg.0);
 270         self
 271     }
 272
 273     /// Configuration for the child process's stdout handle (file descriptor 1).
 274     #[stable(feature = "process", since = "1.0.0")]
 275     pub fn stdout(&mut self, cfg: Stdio) -> &mut Command {
 276         self.inner.stdout(cfg.0);
 277         self
 278     }
 279
 280     /// Configuration for the child process's stderr handle (file descriptor 2).
 281     #[stable(feature = "process", since = "1.0.0")]
 282     pub fn stderr(&mut self, cfg: Stdio) -> &mut Command {
 283         self.inner.stderr(cfg.0);
 284         self
 285     }
 286
 287     /// Executes the command as a child process, returning a handle to it.
 288     ///
 289     /// By default, stdin, stdout and stderr are inherited from the parent.
 290     #[stable(feature = "process", since = "1.0.0")]
 291     pub fn spawn(&mut self) -> io::Result<Child> {
 292         self.inner.spawn(imp::Stdio::Inherit).map(Child::from_inner)
 293     }
 294
 295     /// Executes the command as a child process, waiting for it to finish and
 296     /// collecting all of its output.
 297     ///
 298     /// By default, stdin, stdout and stderr are captured (and used to
 299     /// provide the resulting output).
 300     ///
 301     /// # Examples
 302     ///
 303     /// ```
 304     /// use std::process::Command;
 305     /// let output = Command::new("cat").arg("foo.txt").output().unwrap_or_else(|e| {
 306     ///     panic!("failed to execute process: {}", e)
 307     /// });
 308     ///
 309     /// println!("status: {}", output.status);
 310     /// println!("stdout: {}", String::from_utf8_lossy(&output.stdout));
 311     /// println!("stderr: {}", String::from_utf8_lossy(&output.stderr));
 312     /// ```
 313     #[stable(feature = "process", since = "1.0.0")]
 314     pub fn output(&mut self) -> io::Result<Output> {
 315         self.inner.spawn(imp::Stdio::MakePipe).map(Child::from_inner)
 316             .and_then(|p| p.wait_with_output())
 317     }
 318
 319     /// Executes a command as a child process, waiting for it to finish and
 320     /// collecting its exit status.
 321     ///
 322     /// By default, stdin, stdout and stderr are inherited from the parent.
 323     ///
 324     /// # Examples
 325     ///
 326     /// ```
 327     /// use std::process::Command;
 328     ///
 329     /// let status = Command::new("ls").status().unwrap_or_else(|e| {
 330     ///     panic!("failed to execute process: {}", e)
 331     /// });
 332     ///
 333     /// println!("process exited with: {}", status);
 334     /// ```
 335     #[stable(feature = "process", since = "1.0.0")]
 336     pub fn status(&mut self) -> io::Result<ExitStatus> {
 337         self.spawn().and_then(|mut p| p.wait())
 338     }
 339 }
 340
 341 #[stable(feature = "rust1", since = "1.0.0")]
 342 impl fmt::Debug for Command {
 343     /// Format the program and arguments of a Command for display. Any
 344     /// non-utf8 data is lossily converted using the utf8 replacement
 345     /// character.
 346     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 347         self.inner.fmt(f)
 348     }
 349 }
 350
 351 impl AsInner<imp::Command> for Command {
 352     fn as_inner(&self) -> &imp::Command { &self.inner }
 353 }
 354
 355 impl AsInnerMut<imp::Command> for Command {
 356     fn as_inner_mut(&mut self) -> &mut imp::Command { &mut self.inner }
 357 }
 358
 359 /// The output of a finished process.
 360 #[derive(PartialEq, Eq, Clone)]
 361 #[stable(feature = "process", since = "1.0.0")]
 362 pub struct Output {
 363     /// The status (exit code) of the process.
 364     #[stable(feature = "process", since = "1.0.0")]
 365     pub status: ExitStatus,
 366     /// The data that the process wrote to stdout.
 367     #[stable(feature = "process", since = "1.0.0")]
 368     pub stdout: Vec<u8>,
 369     /// The data that the process wrote to stderr.
 370     #[stable(feature = "process", since = "1.0.0")]
 371     pub stderr: Vec<u8>,
 372 }
 373
 374 // If either stderr or stdout are valid utf8 strings it prints the valid
 375 // strings, otherwise it prints the byte sequence instead
 376 #[stable(feature = "process_output_debug", since = "1.7.0")]
 377 impl fmt::Debug for Output {
 378     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 379
 380         let stdout_utf8 = str::from_utf8(&self.stdout);
 381         let stdout_debug: &fmt::Debug = match stdout_utf8 {
 382             Ok(ref str) => str,
 383             Err(_) => &self.stdout
 384         };
 385
 386         let stderr_utf8 = str::from_utf8(&self.stderr);
 387         let stderr_debug: &fmt::Debug = match stderr_utf8 {
 388             Ok(ref str) => str,
 389             Err(_) => &self.stderr
 390         };
 391
 392         fmt.debug_struct("Output")
 393             .field("status", &self.status)
 394             .field("stdout", stdout_debug)
 395             .field("stderr", stderr_debug)
 396             .finish()
 397     }
 398 }
 399
 400 /// Describes what to do with a standard I/O stream for a child process.
 401 #[stable(feature = "process", since = "1.0.0")]
 402 pub struct Stdio(imp::Stdio);
 403
 404 impl Stdio {
 405     /// A new pipe should be arranged to connect the parent and child processes.
 406     #[stable(feature = "process", since = "1.0.0")]
 407     pub fn piped() -> Stdio { Stdio(imp::Stdio::MakePipe) }
 408
 409     /// The child inherits from the corresponding parent descriptor.
 410     #[stable(feature = "process", since = "1.0.0")]
 411     pub fn inherit() -> Stdio { Stdio(imp::Stdio::Inherit) }
 412
 413     /// This stream will be ignored. This is the equivalent of attaching the
 414     /// stream to `/dev/null`
 415     #[stable(feature = "process", since = "1.0.0")]
 416     pub fn null() -> Stdio { Stdio(imp::Stdio::Null) }
 417 }
 418
 419 impl FromInner<imp::Stdio> for Stdio {
 420     fn from_inner(inner: imp::Stdio) -> Stdio {
 421         Stdio(inner)
 422     }
 423 }
 424
 425 /// Describes the result of a process after it has terminated.
 426 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
 427 #[stable(feature = "process", since = "1.0.0")]
 428 pub struct ExitStatus(imp::ExitStatus);
 429
 430 impl ExitStatus {
 431     /// Was termination successful? Signal termination not considered a success,
 432     /// and success is defined as a zero exit status.
 433     #[stable(feature = "process", since = "1.0.0")]
 434     pub fn success(&self) -> bool {
 435         self.0.success()
 436     }
 437
 438     /// Returns the exit code of the process, if any.
 439     ///
 440     /// On Unix, this will return `None` if the process was terminated
 441     /// by a signal; `std::os::unix` provides an extension trait for
 442     /// extracting the signal and other details from the `ExitStatus`.
 443     #[stable(feature = "process", since = "1.0.0")]
 444     pub fn code(&self) -> Option<i32> {
 445         self.0.code()
 446     }
 447 }
 448
 449 impl AsInner<imp::ExitStatus> for ExitStatus {
 450     fn as_inner(&self) -> &imp::ExitStatus { &self.0 }
 451 }
 452
 453 #[stable(feature = "process", since = "1.0.0")]
 454 impl fmt::Display for ExitStatus {
 455     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 456         self.0.fmt(f)
 457     }
 458 }
 459
 460 impl Child {
 461     /// Forces the child to exit. This is equivalent to sending a
 462     /// SIGKILL on unix platforms.
 463     #[stable(feature = "process", since = "1.0.0")]
 464     pub fn kill(&mut self) -> io::Result<()> {
 465         self.handle.kill()
 466     }
 467
 468     /// Returns the OS-assigned process identifier associated with this child.
 469     #[stable(feature = "process_id", since = "1.3.0")]
 470     pub fn id(&self) -> u32 {
 471         self.handle.id()
 472     }
 473
 474     /// Waits for the child to exit completely, returning the status that it
 475     /// exited with. This function will continue to have the same return value
 476     /// after it has been called at least once.
 477     ///
 478     /// The stdin handle to the child process, if any, will be closed
 479     /// before waiting. This helps avoid deadlock: it ensures that the
 480     /// child does not block waiting for input from the parent, while
 481     /// the parent waits for the child to exit.
 482     #[stable(feature = "process", since = "1.0.0")]
 483     pub fn wait(&mut self) -> io::Result<ExitStatus> {
 484         drop(self.stdin.take());
 485         self.handle.wait().map(ExitStatus)
 486     }
 487
 488     /// Simultaneously waits for the child to exit and collect all remaining
 489     /// output on the stdout/stderr handles, returning an `Output`
 490     /// instance.
 491     ///
 492     /// The stdin handle to the child process, if any, will be closed
 493     /// before waiting. This helps avoid deadlock: it ensures that the
 494     /// child does not block waiting for input from the parent, while
 495     /// the parent waits for the child to exit.
 496     #[stable(feature = "process", since = "1.0.0")]
 497     pub fn wait_with_output(mut self) -> io::Result<Output> {
 498         drop(self.stdin.take());
 499         fn read<R>(mut input: R) -> JoinHandle<io::Result<Vec<u8>>>
 500             where R: Read + Send + 'static
 501         {
 502             thread::spawn(move || {
 503                 let mut ret = Vec::new();
 504                 input.read_to_end(&mut ret).map(|_| ret)
 505             })
 506         }
 507         let stdout = self.stdout.take().map(read);
 508         let stderr = self.stderr.take().map(read);
 509         let status = try!(self.wait());
 510         let stdout = stdout.and_then(|t| t.join().unwrap().ok());
 511         let stderr = stderr.and_then(|t| t.join().unwrap().ok());
 512
 513         Ok(Output {
 514             status: status,
 515             stdout: stdout.unwrap_or(Vec::new()),
 516             stderr: stderr.unwrap_or(Vec::new()),
 517         })
 518     }
 519 }
 520
 521 /// Terminates the current process with the specified exit code.
 522 ///
 523 /// This function will never return and will immediately terminate the current
 524 /// process. The exit code is passed through to the underlying OS and will be
 525 /// available for consumption by another process.
 526 ///
 527 /// Note that because this function never returns, and that it terminates the
 528 /// process, no destructors on the current stack or any other thread's stack
 529 /// will be run. If a clean shutdown is needed it is recommended to only call
 530 /// this function at a known point where there are no more destructors left
 531 /// to run.
 532 #[stable(feature = "rust1", since = "1.0.0")]
 533 pub fn exit(code: i32) -> ! {
 534     ::sys_common::cleanup();
 535     ::sys::os::exit(code)
 536 }
 537
 538 #[cfg(test)]
 539 mod tests {
 540     use prelude::v1::*;
 541     use io::prelude::*;
 542
 543     use io::ErrorKind;
 544     use str;
 545     use super::{Command, Output, Stdio};
 546
 547     // FIXME(#10380) these tests should not all be ignored on android.
 548
 549     #[test]
 550     #[cfg_attr(target_os = "android", ignore)]
 551     fn smoke() {
 552         let p = Command::new("true").spawn();
 553         assert!(p.is_ok());
 554         let mut p = p.unwrap();
 555         assert!(p.wait().unwrap().success());
 556     }
 557
 558     #[test]
 559     #[cfg_attr(target_os = "android", ignore)]
 560     fn smoke_failure() {
 561         match Command::new("if-this-is-a-binary-then-the-world-has-ended").spawn() {
 562             Ok(..) => panic!(),
 563             Err(..) => {}
 564         }
 565     }
 566
 567     #[test]
 568     #[cfg_attr(target_os = "android", ignore)]
 569     fn exit_reported_right() {
 570         let p = Command::new("false").spawn();
 571         assert!(p.is_ok());
 572         let mut p = p.unwrap();
 573         assert!(p.wait().unwrap().code() == Some(1));
 574         drop(p.wait());
 575     }
 576
 577     #[test]
 578     #[cfg(unix)]
 579     #[cfg_attr(target_os = "android", ignore)]
 580     fn signal_reported_right() {
 581         use os::unix::process::ExitStatusExt;
 582
 583         let mut p = Command::new("/bin/sh")
 584                             .arg("-c").arg("read a")
 585                             .stdin(Stdio::piped())
 586                             .spawn().unwrap();
 587         p.kill().unwrap();
 588         match p.wait().unwrap().signal() {
 589             Some(9) => {},
 590             result => panic!("not terminated by signal 9 (instead, {:?})",
 591                              result),
 592         }
 593     }
 594
 595     pub fn run_output(mut cmd: Command) -> String {
 596         let p = cmd.spawn();
 597         assert!(p.is_ok());
 598         let mut p = p.unwrap();
 599         assert!(p.stdout.is_some());
 600         let mut ret = String::new();
 601         p.stdout.as_mut().unwrap().read_to_string(&mut ret).unwrap();
 602         assert!(p.wait().unwrap().success());
 603         return ret;
 604     }
 605
 606     #[test]
 607     #[cfg_attr(target_os = "android", ignore)]
 608     fn stdout_works() {
 609         let mut cmd = Command::new("echo");
 610         cmd.arg("foobar").stdout(Stdio::piped());
 611         assert_eq!(run_output(cmd), "foobar\n");
 612     }
 613
 614     #[test]
 615     #[cfg_attr(any(windows, target_os = "android"), ignore)]
 616     fn set_current_dir_works() {
 617         let mut cmd = Command::new("/bin/sh");
 618         cmd.arg("-c").arg("pwd")
 619            .current_dir("/")
 620            .stdout(Stdio::piped());
 621         assert_eq!(run_output(cmd), "/\n");
 622     }
 623
 624     #[test]
 625     #[cfg_attr(any(windows, target_os = "android"), ignore)]
 626     fn stdin_works() {
 627         let mut p = Command::new("/bin/sh")
 628                             .arg("-c").arg("read line; echo $line")
 629                             .stdin(Stdio::piped())
 630                             .stdout(Stdio::piped())
 631                             .spawn().unwrap();
 632         p.stdin.as_mut().unwrap().write("foobar".as_bytes()).unwrap();
 633         drop(p.stdin.take());
 634         let mut out = String::new();
 635         p.stdout.as_mut().unwrap().read_to_string(&mut out).unwrap();
 636         assert!(p.wait().unwrap().success());
 637         assert_eq!(out, "foobar\n");
 638     }
 639
 640
 641     #[test]
 642     #[cfg_attr(target_os = "android", ignore)]
 643     #[cfg(unix)]
 644     fn uid_works() {
 645         use os::unix::prelude::*;
 646         use libc;
 647         let mut p = Command::new("/bin/sh")
 648                             .arg("-c").arg("true")
 649                             .uid(unsafe { libc::getuid() })
 650                             .gid(unsafe { libc::getgid() })
 651                             .spawn().unwrap();
 652         assert!(p.wait().unwrap().success());
 653     }
 654
 655     #[test]
 656     #[cfg_attr(target_os = "android", ignore)]
 657     #[cfg(unix)]
 658     fn uid_to_root_fails() {
 659         use os::unix::prelude::*;
 660         use libc;
 661
 662         // if we're already root, this isn't a valid test. Most of the bots run
 663         // as non-root though (android is an exception).
 664         if unsafe { libc::getuid() == 0 } { return }
 665         assert!(Command::new("/bin/ls").uid(0).gid(0).spawn().is_err());
 666     }
 667
 668     #[test]
 669     #[cfg_attr(target_os = "android", ignore)]
 670     fn test_process_status() {
 671         let mut status = Command::new("false").status().unwrap();
 672         assert!(status.code() == Some(1));
 673
 674         status = Command::new("true").status().unwrap();
 675         assert!(status.success());
 676     }
 677
 678     #[test]
 679     fn test_process_output_fail_to_start() {
 680         match Command::new("/no-binary-by-this-name-should-exist").output() {
 681             Err(e) => assert_eq!(e.kind(), ErrorKind::NotFound),
 682             Ok(..) => panic!()
 683         }
 684     }
 685
 686     #[test]
 687     #[cfg_attr(target_os = "android", ignore)]
 688     fn test_process_output_output() {
 689         let Output {status, stdout, stderr}
 690              = Command::new("echo").arg("hello").output().unwrap();
 691         let output_str = str::from_utf8(&stdout).unwrap();
 692
 693         assert!(status.success());
 694         assert_eq!(output_str.trim().to_string(), "hello");
 695         assert_eq!(stderr, Vec::new());
 696     }
 697
 698     #[test]
 699     #[cfg_attr(target_os = "android", ignore)]
 700     fn test_process_output_error() {
 701         let Output {status, stdout, stderr}
 702              = Command::new("mkdir").arg(".").output().unwrap();
 703
 704         assert!(status.code() == Some(1));
 705         assert_eq!(stdout, Vec::new());
 706         assert!(!stderr.is_empty());
 707     }
 708
 709     #[test]
 710     #[cfg_attr(target_os = "android", ignore)]
 711     fn test_finish_once() {
 712         let mut prog = Command::new("false").spawn().unwrap();
 713         assert!(prog.wait().unwrap().code() == Some(1));
 714     }
 715
 716     #[test]
 717     #[cfg_attr(target_os = "android", ignore)]
 718     fn test_finish_twice() {
 719         let mut prog = Command::new("false").spawn().unwrap();
 720         assert!(prog.wait().unwrap().code() == Some(1));
 721         assert!(prog.wait().unwrap().code() == Some(1));
 722     }
 723
 724     #[test]
 725     #[cfg_attr(target_os = "android", ignore)]
 726     fn test_wait_with_output_once() {
 727         let prog = Command::new("echo").arg("hello").stdout(Stdio::piped())
 728             .spawn().unwrap();
 729         let Output {status, stdout, stderr} = prog.wait_with_output().unwrap();
 730         let output_str = str::from_utf8(&stdout).unwrap();
 731
 732         assert!(status.success());
 733         assert_eq!(output_str.trim().to_string(), "hello");
 734         assert_eq!(stderr, Vec::new());
 735     }
 736
 737     #[cfg(all(unix, not(target_os="android")))]
 738     pub fn env_cmd() -> Command {
 739         Command::new("env")
 740     }
 741     #[cfg(target_os="android")]
 742     pub fn env_cmd() -> Command {
 743         let mut cmd = Command::new("/system/bin/sh");
 744         cmd.arg("-c").arg("set");
 745         cmd
 746     }
 747
 748     #[cfg(windows)]
 749     pub fn env_cmd() -> Command {
 750         let mut cmd = Command::new("cmd");
 751         cmd.arg("/c").arg("set");
 752         cmd
 753     }
 754
 755     #[test]
 756     fn test_inherit_env() {
 757         use env;
 758
 759         let result = env_cmd().output().unwrap();
 760         let output = String::from_utf8(result.stdout).unwrap();
 761
 762         for (ref k, ref v) in env::vars() {
 763             // don't check android RANDOM variables
 764             if cfg!(target_os = "android") && *k == "RANDOM" {
 765                 continue
 766             }
 767
 768             // Windows has hidden environment variables whose names start with
 769             // equals signs (`=`). Those do not show up in the output of the
 770             // `set` command.
 771             assert!((cfg!(windows) && k.starts_with("=")) ||
 772                     k.starts_with("DYLD") ||
 773                     output.contains(&format!("{}={}", *k, *v)) ||
 774                     output.contains(&format!("{}='{}'", *k, *v)),
 775                     "output doesn't contain `{}={}`\n{}",
 776                     k, v, output);
 777         }
 778     }
 779
 780     #[test]
 781     fn test_override_env() {
 782         use env;
 783
 784         // In some build environments (such as chrooted Nix builds), `env` can
 785         // only be found in the explicitly-provided PATH env variable, not in
 786         // default places such as /bin or /usr/bin. So we need to pass through
 787         // PATH to our sub-process.
 788         let mut cmd = env_cmd();
 789         cmd.env_clear().env("RUN_TEST_NEW_ENV", "123");
 790         if let Some(p) = env::var_os("PATH") {
 791             cmd.env("PATH", &p);
 792         }
 793         let result = cmd.output().unwrap();
 794         let output = String::from_utf8_lossy(&result.stdout).to_string();
 795
 796         assert!(output.contains("RUN_TEST_NEW_ENV=123"),
 797                 "didn't find RUN_TEST_NEW_ENV inside of:\n\n{}", output);
 798     }
 799
 800     #[test]
 801     fn test_add_to_env() {
 802         let result = env_cmd().env("RUN_TEST_NEW_ENV", "123").output().unwrap();
 803         let output = String::from_utf8_lossy(&result.stdout).to_string();
 804
 805         assert!(output.contains("RUN_TEST_NEW_ENV=123"),
 806                 "didn't find RUN_TEST_NEW_ENV inside of:\n\n{}", output);
 807     }
 808
 809     // Regression tests for #30858.
 810     #[test]
 811     fn test_interior_nul_in_progname_is_error() {
 812         match Command::new("has-some-\0\0s-inside").spawn() {
 813             Err(e) => assert_eq!(e.kind(), ErrorKind::InvalidInput),
 814             Ok(_) => panic!(),
 815         }
 816     }
 817
 818     #[test]
 819     fn test_interior_nul_in_arg_is_error() {
 820         match Command::new("echo").arg("has-some-\0\0s-inside").spawn() {
 821             Err(e) => assert_eq!(e.kind(), ErrorKind::InvalidInput),
 822             Ok(_) => panic!(),
 823         }
 824     }
 825
 826     #[test]
 827     fn test_interior_nul_in_args_is_error() {
 828         match Command::new("echo").args(&["has-some-\0\0s-inside"]).spawn() {
 829             Err(e) => assert_eq!(e.kind(), ErrorKind::InvalidInput),
 830             Ok(_) => panic!(),
 831         }
 832     }
 833
 834     #[test]
 835     fn test_interior_nul_in_current_dir_is_error() {
 836         match Command::new("echo").current_dir("has-some-\0\0s-inside").spawn() {
 837             Err(e) => assert_eq!(e.kind(), ErrorKind::InvalidInput),
 838             Ok(_) => panic!(),
 839         }
 840     }
 841
 842     // Regression tests for #30862.
 843     #[test]
 844     fn test_interior_nul_in_env_key_is_error() {
 845         match env_cmd().env("has-some-\0\0s-inside", "value").spawn() {
 846             Err(e) => assert_eq!(e.kind(), ErrorKind::InvalidInput),
 847             Ok(_) => panic!(),
 848         }
 849     }
 850
 851     #[test]
 852     fn test_interior_nul_in_env_value_is_error() {
 853         match env_cmd().env("key", "has-some-\0\0s-inside").spawn() {
 854             Err(e) => assert_eq!(e.kind(), ErrorKind::InvalidInput),
 855             Ok(_) => panic!(),
 856         }
 857     }
 858 }