duct.rs

Duct is a library for running child processes. Duct makes it easy to build pipelines and redirect IO like a shell. At the same time, Duct helps you write correct, portable code: whitespace is never significant, errors from child processes get reported by default, and a variety of gotchas, bugs, and platform inconsistencies are handled for you the Right Way™.

• Documentation
• Crate
• GitHub repo
• the same library, in Python

Changelog

• v0.13.2
  • Added ReaderHandle::try_wait.
  • Debug output for Expression is more concise.
• v0.13.1
  • Added ReaderHandle::kill.
  • Kill methods no longer wait on IO threads to complete. This avoids blocking on unkilled grandchildren.
• v0.13.0
  • Removed the then method.
  • Added ReaderHandle and Expression::reader.
  • Added Expression::stdout_stderr_swap.
  • Renamed stdin/stdout/stderr to stdin_path/stdout_path/stderr_path.
  • Renamed stdin_handle/stdout_handle/stderr_handle to stdin_file/stdout_file/stderr_file.
  • Renamed input to stdin_bytes.
  • Renamed Handle::output to Handle::into_output.

Examples

Run a command without capturing any output. Here "hi" is printed directly to the terminal:

rust use duct::cmd; cmd!("echo", "hi").run()?;

Capture the standard output of a command. Here "hi" is returned as a String:

rust let stdout = cmd!("echo", "hi").read()?; assert_eq!(stdout, "hi");

Capture the standard output of a pipeline:

rust let stdout = cmd!("echo", "hi").pipe(cmd!("sed", "s/i/o/")).read()?; assert_eq!(stdout, "ho");

Merge standard error into standard output and read both incrementally:

```rust use duct::cmd; use std::io::prelude::*; use std::io::BufReader;

let bigcmd = cmd!("bash", "-c", "echo out && echo err 1>&2"); let reader = bigcmd.stderrtostdout().reader()?; let mut lines = BufReader::new(reader).lines(); asserteq!(lines.next().unwrap()?, "out"); asserteq!(lines.next().unwrap()?, "err"); ```

Children that exit with a non-zero status return an error by default:

rust let result = cmd!("false").run(); assert!(result.is_err());