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 #![allow(non_upper_case_globals)]
  15
  16 use prelude::v1::*;
  17 use io::prelude::*;
  18
  19 use ffi::OsStr;
  20 use fmt;
  21 use io::{self, Error, ErrorKind};
  22 use path;
  23 use sync::mpsc::{channel, Receiver};
  24 use sys::pipe::{self, AnonPipe};
  25 use sys::process as imp;
  26 use sys_common::{AsInner, AsInnerMut, FromInner};
  27 use thread;
  28
  29 /// Representation of a running or exited child process.
  30 ///
  31 /// This structure is used to represent and manage child processes. A child
  32 /// process is created via the `Command` struct, which configures the spawning
  33 /// process and can itself be constructed using a builder-style interface.
  34 ///
  35 /// # Examples
  36 ///
  37 /// ```should_panic
  38 /// use std::process::Command;
  39 ///
  40 /// let mut child = Command::new("/bin/cat")
  41 ///                         .arg("file.txt")
  42 ///                         .spawn()
  43 ///                         .unwrap_or_else(|e| { panic!("failed to execute child: {}", e) });
  44 ///
  45 /// let ecode = child.wait()
  46 ///                  .unwrap_or_else(|e| { panic!("failed to wait on child: {}", e) });
  47 ///
  48 /// assert!(ecode.success());
  49 /// ```
  50 #[stable(feature = "process", since = "1.0.0")]
  51 pub struct Child {
  52     handle: imp::Process,
  53
  54     /// None until wait() or wait_with_output() is called.
  55     status: Option<imp::ExitStatus>,
  56
  57     /// The handle for writing to the child's stdin, if it has been captured
  58     #[stable(feature = "process", since = "1.0.0")]
  59     pub stdin: Option<ChildStdin>,
  60
  61     /// The handle for reading from the child's stdout, if it has been captured
  62     #[stable(feature = "process", since = "1.0.0")]
  63     pub stdout: Option<ChildStdout>,
  64
  65     /// The handle for reading from the child's stderr, if it has been captured
  66     #[stable(feature = "process", since = "1.0.0")]
  67     pub stderr: Option<ChildStderr>,
  68 }
  69
  70 impl AsInner<imp::Process> for Child {
  71     fn as_inner(&self) -> &imp::Process { &self.handle }
  72 }
  73
  74 /// A handle to a child procesess's stdin
  75 #[stable(feature = "process", since = "1.0.0")]
  76 pub struct ChildStdin {
  77     inner: AnonPipe
  78 }
  79
  80 #[stable(feature = "process", since = "1.0.0")]
  81 impl Write for ChildStdin {
  82     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
  83         self.inner.write(buf)
  84     }
  85
  86     fn flush(&mut self) -> io::Result<()> {
  87         Ok(())
  88     }
  89 }
  90
  91 impl AsInner<AnonPipe> for ChildStdin {
  92     fn as_inner(&self) -> &AnonPipe { &self.inner }
  93 }
  94
  95 /// A handle to a child procesess's stdout
  96 #[stable(feature = "process", since = "1.0.0")]
  97 pub struct ChildStdout {
  98     inner: AnonPipe
  99 }
 100
 101 #[stable(feature = "process", since = "1.0.0")]
 102 impl Read for ChildStdout {
 103     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
 104         self.inner.read(buf)
 105     }
 106 }
 107
 108 impl AsInner<AnonPipe> for ChildStdout {
 109     fn as_inner(&self) -> &AnonPipe { &self.inner }
 110 }
 111
 112 /// A handle to a child procesess's stderr
 113 #[stable(feature = "process", since = "1.0.0")]
 114 pub struct ChildStderr {
 115     inner: AnonPipe
 116 }
 117
 118 #[stable(feature = "process", since = "1.0.0")]
 119 impl Read for ChildStderr {
 120     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
 121         self.inner.read(buf)
 122     }
 123 }
 124
 125 impl AsInner<AnonPipe> for ChildStderr {
 126     fn as_inner(&self) -> &AnonPipe { &self.inner }
 127 }
 128
 129 /// The `Command` type acts as a process builder, providing fine-grained control
 130 /// over how a new process should be spawned. A default configuration can be
 131 /// generated using `Command::new(program)`, where `program` gives a path to the
 132 /// program to be executed. Additional builder methods allow the configuration
 133 /// to be changed (for example, by adding arguments) prior to spawning:
 134 ///
 135 /// ```
 136 /// use std::process::Command;
 137 ///
 138 /// let output = Command::new("sh")
 139 ///                      .arg("-c")
 140 ///                      .arg("echo hello")
 141 ///                      .output()
 142 ///                      .unwrap_or_else(|e| { panic!("failed to execute process: {}", e) });
 143 /// let hello = output.stdout;
 144 /// ```
 145 #[stable(feature = "process", since = "1.0.0")]
 146 pub struct Command {
 147     inner: imp::Command,
 148
 149     // Details explained in the builder methods
 150     stdin: Option<Stdio>,
 151     stdout: Option<Stdio>,
 152     stderr: Option<Stdio>,
 153 }
 154
 155 impl Command {
 156     /// Constructs a new `Command` for launching the program at
 157     /// path `program`, with the following default configuration:
 158     ///
 159     /// * No arguments to the program
 160     /// * Inherit the current process's environment
 161     /// * Inherit the current process's working directory
 162     /// * Inherit stdin/stdout/stderr for `spawn` or `status`, but create pipes for `output`
 163     ///
 164     /// Builder methods are provided to change these defaults and
 165     /// otherwise configure the process.
 166     #[stable(feature = "process", since = "1.0.0")]
 167     pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
 168         Command {
 169             inner: imp::Command::new(program.as_ref()),
 170             stdin: None,
 171             stdout: None,
 172             stderr: None,
 173         }
 174     }
 175
 176     /// Add an argument to pass to the program.
 177     #[stable(feature = "process", since = "1.0.0")]
 178     pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Command {
 179         self.inner.arg(arg.as_ref());
 180         self
 181     }
 182
 183     /// Add multiple arguments to pass to the program.
 184     #[stable(feature = "process", since = "1.0.0")]
 185     pub fn args<S: AsRef<OsStr>>(&mut self, args: &[S]) -> &mut Command {
 186         self.inner.args(args.iter().map(AsRef::as_ref));
 187         self
 188     }
 189
 190     /// Inserts or updates an environment variable mapping.
 191     ///
 192     /// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
 193     /// and case-sensitive on all other platforms.
 194     #[stable(feature = "process", since = "1.0.0")]
 195     pub fn env<K, V>(&mut self, key: K, val: V) -> &mut Command
 196         where K: AsRef<OsStr>, V: AsRef<OsStr>
 197     {
 198         self.inner.env(key.as_ref(), val.as_ref());
 199         self
 200     }
 201
 202     /// Removes an environment variable mapping.
 203     #[stable(feature = "process", since = "1.0.0")]
 204     pub fn env_remove<K: AsRef<OsStr>>(&mut self, key: K) -> &mut Command {
 205         self.inner.env_remove(key.as_ref());
 206         self
 207     }
 208
 209     /// Clears the entire environment map for the child process.
 210     #[stable(feature = "process", since = "1.0.0")]
 211     pub fn env_clear(&mut self) -> &mut Command {
 212         self.inner.env_clear();
 213         self
 214     }
 215
 216     /// Sets the working directory for the child process.
 217     #[stable(feature = "process", since = "1.0.0")]
 218     pub fn current_dir<P: AsRef<path::Path>>(&mut self, dir: P) -> &mut Command {
 219         self.inner.cwd(dir.as_ref().as_ref());
 220         self
 221     }
 222
 223     /// Configuration for the child process's stdin handle (file descriptor 0).
 224     #[stable(feature = "process", since = "1.0.0")]
 225     pub fn stdin(&mut self, cfg: Stdio) -> &mut Command {
 226         self.stdin = Some(cfg);
 227         self
 228     }
 229
 230     /// Configuration for the child process's stdout handle (file descriptor 1).
 231     #[stable(feature = "process", since = "1.0.0")]
 232     pub fn stdout(&mut self, cfg: Stdio) -> &mut Command {
 233         self.stdout = Some(cfg);
 234         self
 235     }
 236
 237     /// Configuration for the child process's stderr handle (file descriptor 2).
 238     #[stable(feature = "process", since = "1.0.0")]
 239     pub fn stderr(&mut self, cfg: Stdio) -> &mut Command {
 240         self.stderr = Some(cfg);
 241         self
 242     }
 243
 244     fn spawn_inner(&self, default_io: StdioImp) -> io::Result<Child> {
 245         let default_io = Stdio(default_io);
 246
 247         // See comment on `setup_io` for what `_drop_later` is.
 248         let (their_stdin, our_stdin, _drop_later) = try!(
 249             setup_io(self.stdin.as_ref().unwrap_or(&default_io), true)
 250         );
 251         let (their_stdout, our_stdout, _drop_later) = try!(
 252             setup_io(self.stdout.as_ref().unwrap_or(&default_io), false)
 253         );
 254         let (their_stderr, our_stderr, _drop_later) = try!(
 255             setup_io(self.stderr.as_ref().unwrap_or(&default_io), false)
 256         );
 257
 258         match imp::Process::spawn(&self.inner, their_stdin, their_stdout,
 259                                   their_stderr) {
 260             Err(e) => Err(e),
 261             Ok(handle) => Ok(Child {
 262                 handle: handle,
 263                 status: None,
 264                 stdin: our_stdin.map(|fd| ChildStdin { inner: fd }),
 265                 stdout: our_stdout.map(|fd| ChildStdout { inner: fd }),
 266                 stderr: our_stderr.map(|fd| ChildStderr { inner: fd }),
 267             })
 268         }
 269     }
 270
 271     /// Executes the command as a child process, returning a handle to it.
 272     ///
 273     /// By default, stdin, stdout and stderr are inherited from the parent.
 274     #[stable(feature = "process", since = "1.0.0")]
 275     pub fn spawn(&mut self) -> io::Result<Child> {
 276         self.spawn_inner(StdioImp::Inherit)
 277     }
 278
 279     /// Executes the command as a child process, waiting for it to finish and
 280     /// collecting all of its output.
 281     ///
 282     /// By default, stdin, stdout and stderr are captured (and used to
 283     /// provide the resulting output).
 284     ///
 285     /// # Examples
 286     ///
 287     /// ```
 288     /// use std::process::Command;
 289     /// let output = Command::new("cat").arg("foo.txt").output().unwrap_or_else(|e| {
 290     ///     panic!("failed to execute process: {}", e)
 291     /// });
 292     ///
 293     /// println!("status: {}", output.status);
 294     /// println!("stdout: {}", String::from_utf8_lossy(&output.stdout));
 295     /// println!("stderr: {}", String::from_utf8_lossy(&output.stderr));
 296     /// ```
 297     #[stable(feature = "process", since = "1.0.0")]
 298     pub fn output(&mut self) -> io::Result<Output> {
 299         self.spawn_inner(StdioImp::MakePipe).and_then(|p| p.wait_with_output())
 300     }
 301
 302     /// Executes a command as a child process, waiting for it to finish and
 303     /// collecting its exit status.
 304     ///
 305     /// By default, stdin, stdout and stderr are inherited from the parent.
 306     ///
 307     /// # Examples
 308     ///
 309     /// ```
 310     /// use std::process::Command;
 311     ///
 312     /// let status = Command::new("ls").status().unwrap_or_else(|e| {
 313     ///     panic!("failed to execute process: {}", e)
 314     /// });
 315     ///
 316     /// println!("process exited with: {}", status);
 317     /// ```
 318     #[stable(feature = "process", since = "1.0.0")]
 319     pub fn status(&mut self) -> io::Result<ExitStatus> {
 320         self.spawn().and_then(|mut p| p.wait())
 321     }
 322 }
 323
 324 #[stable(feature = "rust1", since = "1.0.0")]
 325 impl fmt::Debug for Command {
 326     /// Format the program and arguments of a Command for display. Any
 327     /// non-utf8 data is lossily converted using the utf8 replacement
 328     /// character.
 329     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 330         try!(write!(f, "{:?}", self.inner.program));
 331         for arg in &self.inner.args {
 332             try!(write!(f, " {:?}", arg));
 333         }
 334         Ok(())
 335     }
 336 }
 337
 338 impl AsInner<imp::Command> for Command {
 339     fn as_inner(&self) -> &imp::Command { &self.inner }
 340 }
 341
 342 impl AsInnerMut<imp::Command> for Command {
 343     fn as_inner_mut(&mut self) -> &mut imp::Command { &mut self.inner }
 344 }
 345
 346 // Takes a `Stdio` configuration (this module) and whether the to-be-owned
 347 // handle will be readable.
 348 //
 349 // Returns a triple of (stdio to spawn with, stdio to store, stdio to drop). The
 350 // stdio to spawn with is passed down to the `sys` module and indicates how the
 351 // stdio stream should be set up. The "stdio to store" is an object which
 352 // should be returned in the `Child` that makes its way out. The "stdio to drop"
 353 // represents the raw value of "stdio to spawn with", but is the owned variant
 354 // for it. This needs to be dropped after the child spawns
 355 fn setup_io(io: &Stdio, readable: bool)
 356             -> io::Result<(imp::Stdio, Option<AnonPipe>, Option<AnonPipe>)>
 357 {
 358     Ok(match io.0 {
 359         StdioImp::MakePipe => {
 360             let (reader, writer) = try!(pipe::anon_pipe());
 361             if readable {
 362                 (imp::Stdio::Raw(reader.raw()), Some(writer), Some(reader))
 363             } else {
 364                 (imp::Stdio::Raw(writer.raw()), Some(reader), Some(writer))
 365             }
 366         }
 367         StdioImp::Raw(ref owned) => (imp::Stdio::Raw(owned.raw()), None, None),
 368         StdioImp::Inherit => (imp::Stdio::Inherit, None, None),
 369         StdioImp::None => (imp::Stdio::None, None, None),
 370     })
 371 }
 372
 373 /// The output of a finished process.
 374 #[derive(PartialEq, Eq, Clone)]
 375 #[stable(feature = "process", since = "1.0.0")]
 376 pub struct Output {
 377     /// The status (exit code) of the process.
 378     #[stable(feature = "process", since = "1.0.0")]
 379     pub status: ExitStatus,
 380     /// The data that the process wrote to stdout.
 381     #[stable(feature = "process", since = "1.0.0")]
 382     pub stdout: Vec<u8>,
 383     /// The data that the process wrote to stderr.
 384     #[stable(feature = "process", since = "1.0.0")]
 385     pub stderr: Vec<u8>,
 386 }
 387
 388 /// Describes what to do with a standard I/O stream for a child process.
 389 #[stable(feature = "process", since = "1.0.0")]
 390 pub struct Stdio(StdioImp);
 391
 392 // The internal enum for stdio setup; see below for descriptions.
 393 enum StdioImp {
 394     MakePipe,
 395     Raw(imp::RawStdio),
 396     Inherit,
 397     None,
 398 }
 399
 400 impl Stdio {
 401     /// A new pipe should be arranged to connect the parent and child processes.
 402     #[stable(feature = "process", since = "1.0.0")]
 403     pub fn piped() -> Stdio { Stdio(StdioImp::MakePipe) }
 404
 405     /// The child inherits from the corresponding parent descriptor.
 406     #[stable(feature = "process", since = "1.0.0")]
 407     pub fn inherit() -> Stdio { Stdio(StdioImp::Inherit) }
 408
 409     /// This stream will be ignored. This is the equivalent of attaching the
 410     /// stream to `/dev/null`
 411     #[stable(feature = "process", since = "1.0.0")]
 412     pub fn null() -> Stdio { Stdio(StdioImp::None) }
 413 }
 414
 415 impl FromInner<imp::RawStdio> for Stdio {
 416     fn from_inner(inner: imp::RawStdio) -> Stdio {
 417         Stdio(StdioImp::Raw(inner))
 418     }
 419 }
 420
 421 /// Describes the result of a process after it has terminated.
 422 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
 423 #[stable(feature = "process", since = "1.0.0")]
 424 pub struct ExitStatus(imp::ExitStatus);
 425
 426 impl ExitStatus {
 427     /// Was termination successful? Signal termination not considered a success,
 428     /// and success is defined as a zero exit status.
 429     #[stable(feature = "process", since = "1.0.0")]
 430     pub fn success(&self) -> bool {
 431         self.0.success()
 432     }
 433
 434     /// Returns the exit code of the process, if any.
 435     ///
 436     /// On Unix, this will return `None` if the process was terminated
 437     /// by a signal; `std::os::unix` provides an extension trait for
 438     /// extracting the signal and other details from the `ExitStatus`.
 439     #[stable(feature = "process", since = "1.0.0")]
 440     pub fn code(&self) -> Option<i32> {
 441         self.0.code()
 442     }
 443 }
 444
 445 impl AsInner<imp::ExitStatus> for ExitStatus {
 446     fn as_inner(&self) -> &imp::ExitStatus { &self.0 }
 447 }
 448
 449 #[stable(feature = "process", since = "1.0.0")]
 450 impl fmt::Display for ExitStatus {
 451     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 452         self.0.fmt(f)
 453     }
 454 }
 455
 456 impl Child {
 457     /// Forces the child to exit. This is equivalent to sending a
 458     /// SIGKILL on unix platforms.
 459     #[stable(feature = "process", since = "1.0.0")]
 460     pub fn kill(&mut self) -> io::Result<()> {
 461         #[cfg(unix)] fn collect_status(p: &mut Child) {
 462             // On Linux (and possibly other unices), a process that has exited will
 463             // continue to accept signals because it is "defunct". The delivery of
 464             // signals will only fail once the child has been reaped. For this
 465             // reason, if the process hasn't exited yet, then we attempt to collect
 466             // their status with WNOHANG.
 467             if p.status.is_none() {
 468                 match p.handle.try_wait() {
 469                     Some(status) => { p.status = Some(status); }
 470                     None => {}
 471                 }
 472             }
 473         }
 474         #[cfg(windows)] fn collect_status(_p: &mut Child) {}
 475
 476         collect_status(self);
 477
 478         // if the process has finished, and therefore had waitpid called,
 479         // and we kill it, then on unix we might ending up killing a
 480         // newer process that happens to have the same (re-used) id
 481         if self.status.is_some() {
 482             return Err(Error::new(
 483                 ErrorKind::InvalidInput,
 484                 "invalid argument: can't kill an exited process",
 485             ))
 486         }
 487
 488         unsafe { self.handle.kill() }
 489     }
 490
 491     /// Returns the OS-assigned process identifier associated with this child.
 492     #[unstable(feature = "process_id", reason = "api recently added")]
 493     pub fn id(&self) -> u32 {
 494         self.handle.id()
 495     }
 496
 497     /// Waits for the child to exit completely, returning the status that it
 498     /// exited with. This function will continue to have the same return value
 499     /// after it has been called at least once.
 500     ///
 501     /// The stdin handle to the child process, if any, will be closed
 502     /// before waiting. This helps avoid deadlock: it ensures that the
 503     /// child does not block waiting for input from the parent, while
 504     /// the parent waits for the child to exit.
 505     #[stable(feature = "process", since = "1.0.0")]
 506     pub fn wait(&mut self) -> io::Result<ExitStatus> {
 507         drop(self.stdin.take());
 508         match self.status {
 509             Some(code) => Ok(ExitStatus(code)),
 510             None => {
 511                 let status = try!(self.handle.wait());
 512                 self.status = Some(status);
 513                 Ok(ExitStatus(status))
 514             }
 515         }
 516     }
 517
 518     /// Simultaneously waits for the child to exit and collect all remaining
 519     /// output on the stdout/stderr handles, returning a `Output`
 520     /// instance.
 521     ///
 522     /// The stdin handle to the child process, if any, will be closed
 523     /// before waiting. This helps avoid deadlock: it ensures that the
 524     /// child does not block waiting for input from the parent, while
 525     /// the parent waits for the child to exit.
 526     #[stable(feature = "process", since = "1.0.0")]
 527     pub fn wait_with_output(mut self) -> io::Result<Output> {
 528         drop(self.stdin.take());
 529         fn read<T: Read + Send + 'static>(stream: Option<T>) -> Receiver<io::Result<Vec<u8>>> {
 530             let (tx, rx) = channel();
 531             match stream {
 532                 Some(stream) => {
 533                     thread::spawn(move || {
 534                         let mut stream = stream;
 535                         let mut ret = Vec::new();
 536                         let res = stream.read_to_end(&mut ret);
 537                         tx.send(res.map(|_| ret)).unwrap();
 538                     });
 539                 }
 540                 None => tx.send(Ok(Vec::new())).unwrap()
 541             }
 542             rx
 543         }
 544         let stdout = read(self.stdout.take());
 545         let stderr = read(self.stderr.take());
 546         let status = try!(self.wait());
 547
 548         Ok(Output {
 549             status: status,
 550             stdout: stdout.recv().unwrap().unwrap_or(Vec::new()),
 551             stderr:  stderr.recv().unwrap().unwrap_or(Vec::new()),
 552         })
 553     }
 554 }
 555
 556 /// Terminates the current process with the specified exit code.
 557 ///
 558 /// This function will never return and will immediately terminate the current
 559 /// process. The exit code is passed through to the underlying OS and will be
 560 /// available for consumption by another process.
 561 ///
 562 /// Note that because this function never returns, and that it terminates the
 563 /// process, no destructors on the current stack or any other thread's stack
 564 /// will be run. If a clean shutdown is needed it is recommended to only call
 565 /// this function at a known point where there are no more destructors left
 566 /// to run.
 567 #[stable(feature = "rust1", since = "1.0.0")]
 568 pub fn exit(code: i32) -> ! {
 569     ::sys::os::exit(code)
 570 }
 571
 572 #[cfg(test)]
 573 mod tests {
 574     use prelude::v1::*;
 575     use io::prelude::*;
 576
 577     use io::ErrorKind;
 578     use rt::running_on_valgrind;
 579     use str;
 580     use super::{Command, Output, Stdio};
 581
 582     // FIXME(#10380) these tests should not all be ignored on android.
 583
 584     #[cfg(not(target_os="android"))]
 585     #[test]
 586     fn smoke() {
 587         let p = Command::new("true").spawn();
 588         assert!(p.is_ok());
 589         let mut p = p.unwrap();
 590         assert!(p.wait().unwrap().success());
 591     }
 592
 593     #[cfg(not(target_os="android"))]
 594     #[test]
 595     fn smoke_failure() {
 596         match Command::new("if-this-is-a-binary-then-the-world-has-ended").spawn() {
 597             Ok(..) => panic!(),
 598             Err(..) => {}
 599         }
 600     }
 601
 602     #[cfg(not(target_os="android"))]
 603     #[test]
 604     fn exit_reported_right() {
 605         let p = Command::new("false").spawn();
 606         assert!(p.is_ok());
 607         let mut p = p.unwrap();
 608         assert!(p.wait().unwrap().code() == Some(1));
 609         drop(p.wait());
 610     }
 611
 612     #[cfg(all(unix, not(target_os="android")))]
 613     #[test]
 614     fn signal_reported_right() {
 615         use os::unix::process::ExitStatusExt;
 616
 617         let p = Command::new("/bin/sh").arg("-c").arg("kill -9 $$").spawn();
 618         assert!(p.is_ok());
 619         let mut p = p.unwrap();
 620         match p.wait().unwrap().signal() {
 621             Some(9) => {},
 622             result => panic!("not terminated by signal 9 (instead, {:?})", result),
 623         }
 624     }
 625
 626     pub fn run_output(mut cmd: Command) -> String {
 627         let p = cmd.spawn();
 628         assert!(p.is_ok());
 629         let mut p = p.unwrap();
 630         assert!(p.stdout.is_some());
 631         let mut ret = String::new();
 632         p.stdout.as_mut().unwrap().read_to_string(&mut ret).unwrap();
 633         assert!(p.wait().unwrap().success());
 634         return ret;
 635     }
 636
 637     #[cfg(not(target_os="android"))]
 638     #[test]
 639     fn stdout_works() {
 640         let mut cmd = Command::new("echo");
 641         cmd.arg("foobar").stdout(Stdio::piped());
 642         assert_eq!(run_output(cmd), "foobar\n");
 643     }
 644
 645     #[cfg(all(unix, not(target_os="android")))]
 646     #[test]
 647     fn set_current_dir_works() {
 648         let mut cmd = Command::new("/bin/sh");
 649         cmd.arg("-c").arg("pwd")
 650            .current_dir("/")
 651            .stdout(Stdio::piped());
 652         assert_eq!(run_output(cmd), "/\n");
 653     }
 654
 655     #[cfg(all(unix, not(target_os="android")))]
 656     #[test]
 657     fn stdin_works() {
 658         let mut p = Command::new("/bin/sh")
 659                             .arg("-c").arg("read line; echo $line")
 660                             .stdin(Stdio::piped())
 661                             .stdout(Stdio::piped())
 662                             .spawn().unwrap();
 663         p.stdin.as_mut().unwrap().write("foobar".as_bytes()).unwrap();
 664         drop(p.stdin.take());
 665         let mut out = String::new();
 666         p.stdout.as_mut().unwrap().read_to_string(&mut out).unwrap();
 667         assert!(p.wait().unwrap().success());
 668         assert_eq!(out, "foobar\n");
 669     }
 670
 671
 672     #[cfg(all(unix, not(target_os="android")))]
 673     #[test]
 674     fn uid_works() {
 675         use os::unix::prelude::*;
 676         use libc;
 677         let mut p = Command::new("/bin/sh")
 678                             .arg("-c").arg("true")
 679                             .uid(unsafe { libc::getuid() })
 680                             .gid(unsafe { libc::getgid() })
 681                             .spawn().unwrap();
 682         assert!(p.wait().unwrap().success());
 683     }
 684
 685     #[cfg(all(unix, not(target_os="android")))]
 686     #[test]
 687     fn uid_to_root_fails() {
 688         use os::unix::prelude::*;
 689         use libc;
 690
 691         // if we're already root, this isn't a valid test. Most of the bots run
 692         // as non-root though (android is an exception).
 693         if unsafe { libc::getuid() == 0 } { return }
 694         assert!(Command::new("/bin/ls").uid(0).gid(0).spawn().is_err());
 695     }
 696
 697     #[cfg(not(target_os="android"))]
 698     #[test]
 699     fn test_process_status() {
 700         let mut status = Command::new("false").status().unwrap();
 701         assert!(status.code() == Some(1));
 702
 703         status = Command::new("true").status().unwrap();
 704         assert!(status.success());
 705     }
 706
 707     #[test]
 708     fn test_process_output_fail_to_start() {
 709         match Command::new("/no-binary-by-this-name-should-exist").output() {
 710             Err(e) => assert_eq!(e.kind(), ErrorKind::NotFound),
 711             Ok(..) => panic!()
 712         }
 713     }
 714
 715     #[cfg(not(target_os="android"))]
 716     #[test]
 717     fn test_process_output_output() {
 718         let Output {status, stdout, stderr}
 719              = Command::new("echo").arg("hello").output().unwrap();
 720         let output_str = str::from_utf8(&stdout).unwrap();
 721
 722         assert!(status.success());
 723         assert_eq!(output_str.trim().to_string(), "hello");
 724         // FIXME #7224
 725         if !running_on_valgrind() {
 726             assert_eq!(stderr, Vec::new());
 727         }
 728     }
 729
 730     #[cfg(not(target_os="android"))]
 731     #[test]
 732     fn test_process_output_error() {
 733         let Output {status, stdout, stderr}
 734              = Command::new("mkdir").arg(".").output().unwrap();
 735
 736         assert!(status.code() == Some(1));
 737         assert_eq!(stdout, Vec::new());
 738         assert!(!stderr.is_empty());
 739     }
 740
 741     #[cfg(not(target_os="android"))]
 742     #[test]
 743     fn test_finish_once() {
 744         let mut prog = Command::new("false").spawn().unwrap();
 745         assert!(prog.wait().unwrap().code() == Some(1));
 746     }
 747
 748     #[cfg(not(target_os="android"))]
 749     #[test]
 750     fn test_finish_twice() {
 751         let mut prog = Command::new("false").spawn().unwrap();
 752         assert!(prog.wait().unwrap().code() == Some(1));
 753         assert!(prog.wait().unwrap().code() == Some(1));
 754     }
 755
 756     #[cfg(not(target_os="android"))]
 757     #[test]
 758     fn test_wait_with_output_once() {
 759         let prog = Command::new("echo").arg("hello").stdout(Stdio::piped())
 760             .spawn().unwrap();
 761         let Output {status, stdout, stderr} = prog.wait_with_output().unwrap();
 762         let output_str = str::from_utf8(&stdout).unwrap();
 763
 764         assert!(status.success());
 765         assert_eq!(output_str.trim().to_string(), "hello");
 766         // FIXME #7224
 767         if !running_on_valgrind() {
 768             assert_eq!(stderr, Vec::new());
 769         }
 770     }
 771
 772     #[cfg(all(unix, not(target_os="android")))]
 773     pub fn env_cmd() -> Command {
 774         Command::new("env")
 775     }
 776     #[cfg(target_os="android")]
 777     pub fn env_cmd() -> Command {
 778         let mut cmd = Command::new("/system/bin/sh");
 779         cmd.arg("-c").arg("set");
 780         cmd
 781     }
 782
 783     #[cfg(windows)]
 784     pub fn env_cmd() -> Command {
 785         let mut cmd = Command::new("cmd");
 786         cmd.arg("/c").arg("set");
 787         cmd
 788     }
 789
 790     #[cfg(not(target_os="android"))]
 791     #[test]
 792     fn test_inherit_env() {
 793         use std::env;
 794         if running_on_valgrind() { return; }
 795
 796         let result = env_cmd().output().unwrap();
 797         let output = String::from_utf8(result.stdout).unwrap();
 798
 799         for (ref k, ref v) in env::vars() {
 800             // don't check windows magical empty-named variables
 801             assert!(k.is_empty() ||
 802                     output.contains(&format!("{}={}", *k, *v)),
 803                     "output doesn't contain `{}={}`\n{}",
 804                     k, v, output);
 805         }
 806     }
 807     #[cfg(target_os="android")]
 808     #[test]
 809     fn test_inherit_env() {
 810         use std::env;
 811         if running_on_valgrind() { return; }
 812
 813         let mut result = env_cmd().output().unwrap();
 814         let output = String::from_utf8(result.stdout).unwrap();
 815
 816         for (ref k, ref v) in env::vars() {
 817             // don't check android RANDOM variables
 818             if *k != "RANDOM".to_string() {
 819                 assert!(output.contains(&format!("{}={}",
 820                                                  *k,
 821                                                  *v)) ||
 822                         output.contains(&format!("{}=\'{}\'",
 823                                                  *k,
 824                                                  *v)));
 825             }
 826         }
 827     }
 828
 829     #[test]
 830     fn test_override_env() {
 831         use env;
 832
 833         // In some build environments (such as chrooted Nix builds), `env` can
 834         // only be found in the explicitly-provided PATH env variable, not in
 835         // default places such as /bin or /usr/bin. So we need to pass through
 836         // PATH to our sub-process.
 837         let mut cmd = env_cmd();
 838         cmd.env_clear().env("RUN_TEST_NEW_ENV", "123");
 839         if let Some(p) = env::var_os("PATH") {
 840             cmd.env("PATH", &p);
 841         }
 842         let result = cmd.output().unwrap();
 843         let output = String::from_utf8_lossy(&result.stdout).to_string();
 844
 845         assert!(output.contains("RUN_TEST_NEW_ENV=123"),
 846                 "didn't find RUN_TEST_NEW_ENV inside of:\n\n{}", output);
 847     }
 848
 849     #[test]
 850     fn test_add_to_env() {
 851         let result = env_cmd().env("RUN_TEST_NEW_ENV", "123").output().unwrap();
 852         let output = String::from_utf8_lossy(&result.stdout).to_string();
 853
 854         assert!(output.contains("RUN_TEST_NEW_ENV=123"),
 855                 "didn't find RUN_TEST_NEW_ENV inside of:\n\n{}", output);
 856     }
 857 }