std​::io​::process

Structs

CommandProcessProcessOutput

Struct std::io::process::Command[src]

pub struct Command {
    // some fields omitted
}

The Command type acts as a process builder, providing fine-grained control over how a new process should be spawned. A default configuration can be generated using Command::new(program), where program gives a path to the program to be executed. Additional builder methods allow the configuration to be changed (for example, by adding arguments) prior to spawning:

fn main() { use std::io::Command; let mut process = match Command::new("sh").arg("-c").arg("echo hello").spawn() { Ok(p) => p, Err(e) => fail!("failed to execute process: {}", e), }; let output = process.stdout.get_mut_ref().read_to_end(); }
use std::io::Command;

let mut process = match Command::new("sh").arg("-c").arg("echo hello").spawn() {
  Ok(p) => p,
  Err(e) => fail!("failed to execute process: {}", e),
};

let output = process.stdout.get_mut_ref().read_to_end();

Methods

impl Command

fn new<T: ToCStr>(program: T) -> Command

Constructs a new Command for launching the program at path program, with the following default configuration:

  • No arguments to the program
  • Inherit the current process's environment
  • Inherit the current process's working directory
  • A readable pipe for stdin (file descriptor 0)
  • A writeable pipe for stdout and stderr (file descriptors 1 and 2)

Builder methods are provided to change these defaults and otherwise configure the process.

fn arg<'a, T: ToCStr>(&'a mut self, arg: T) -> &'a mut Command

Add an argument to pass to the program.

fn args<'a, T: ToCStr>(&'a mut self, args: &[T]) -> &'a mut Command

Add multiple arguments to pass to the program.

fn env<'a, T: ToCStr>(&'a mut self, env: &[(T, T)]) -> &'a mut Command

Sets the environment for the child process (rather than inheriting it from the current process).

fn cwd<'a>(&'a mut self, dir: &Path) -> &'a mut Command

Set the working directory for the child process.

fn stdin<'a>(&'a mut self, cfg: StdioContainer) -> &'a mut Command

Configuration for the child process's stdin handle (file descriptor 0). Defaults to CreatePipe(true, false) so the input can be written to.

fn stdout<'a>(&'a mut self, cfg: StdioContainer) -> &'a mut Command

Configuration for the child process's stdout handle (file descriptor 1). Defaults to CreatePipe(false, true) so the output can be collected.

fn stderr<'a>(&'a mut self, cfg: StdioContainer) -> &'a mut Command

Configuration for the child process's stderr handle (file descriptor 2). Defaults to CreatePipe(false, true) so the output can be collected.

fn extra_io<'a>(&'a mut self, cfg: StdioContainer) -> &'a mut Command

Attaches a stream/file descriptor/pipe to the child process. Inherited file descriptors are numbered consecutively, starting at 3; the first three file descriptors (stdin/stdout/stderr) are configured with the stdin, stdout, and stderr methods.

fn uid<'a>(&'a mut self, id: uint) -> &'a mut Command

Sets the child process's user id. This translates to a setuid call in the child process. Setting this value on windows will cause the spawn to fail. Failure in the setuid call on unix will also cause the spawn to fail.

fn gid<'a>(&'a mut self, id: uint) -> &'a mut Command

Similar to uid, but sets the group id of the child process. This has the same semantics as the uid field.

fn detached<'a>(&'a mut self) -> &'a mut Command

Sets the child process to be spawned in a detached state. On unix, this means that the child is the leader of a new process group.

fn spawn(&self) -> IoResult<Process>

Executes the command as a child process, which is returned.

fn output(&self) -> IoResult<ProcessOutput>

Executes the command as a child process, waiting for it to finish and collecting all of its output.

Example

fn main() { use std::io::Command; use std::str; let output = match Command::new("cat").arg("foot.txt").output() { Ok(output) => output, Err(e) => fail!("failed to execute process: {}", e), }; println!("status: {}", output.status); println!("stdout: {}", str::from_utf8_lossy(output.output.as_slice())); println!("stderr: {}", str::from_utf8_lossy(output.error.as_slice())); }
use std::io::Command;
use std::str;

let output = match Command::new("cat").arg("foot.txt").output() {
    Ok(output) => output,
    Err(e) => fail!("failed to execute process: {}", e),
};

println!("status: {}", output.status);
println!("stdout: {}", str::from_utf8_lossy(output.output.as_slice()));
println!("stderr: {}", str::from_utf8_lossy(output.error.as_slice()));

fn status(&self) -> IoResult<ProcessExit>

Executes a command as a child process, waiting for it to finish and collecting its exit status.

Example

fn main() { use std::io::Command; let status = match Command::new("ls").status() { Ok(status) => status, Err(e) => fail!("failed to execute process: {}", e), }; println!("process exited with: {}", status); }
use std::io::Command;

let status = match Command::new("ls").status() {
    Ok(status) => status,
    Err(e) => fail!("failed to execute process: {}", e),
};

println!("process exited with: {}", status);

Trait Implementations

impl Show for Command

fn fmt(&self, f: &mut Formatter) -> Result

Format the program and arguments of a Command for display. Any non-utf8 data is lossily converted using the utf8 replacement character.