#Process Library for MoonBit

#Features

• Command Construction: Builder pattern for configuring command, arguments, environment, and working directory.
• I/O Redirection: Support for piping stdin, stdout, and stderr (Inherit, Piped, Null).
• Process Management:
  • spawn() for non-blocking execution yielding a Child handle.
  • Child handle supports:
    • pid(): Access the process ID.
    • wait(): Wait for completion.
    • kill(): Terminate the process.
    • write_stdin(), read_stdout(), read_stderr(), close_stdin(): Manual I/O interaction.
• Convenience: output() method to capture all stdout/stderr and exit status.

#Usage

#Simple Output Capture

test {
  // Example: Running a simple command and capturing output
  let output = try {
    Command::new("moon")
      .arg("version")
      .stdout(Piped) // Capture stdout
      .output()
  } catch {
    e => abort("Failed to execute process: \{e}")
  }

  if output.status.success() {
    println("Command succeeded!")
    // Access output.stdout
  }
}

#Manual Pipe Interaction

test {
  // Example: Writing to stdin and reading from stdout
  // Note: "grep" needs to be available in your PATH (use "findstr" on Windows)
  let child = Command::new("grep")
      .arg("hello")
      .stdin(Piped)
      .stdout(Piped)
      .spawn()
  // Write to stdin
  let input = @utf8.encode("hello world\ngoodbye\n")
  let _ = child.write_stdin(input)
  child.close_stdin() // Signal EOF

  // Read from stdout
  let buf = Bytes::make(1024, b'\x00')
  let n = child.read_stdout(buf)
  if n > 0 {
      let _out_str = @utf8.decode(buf) // "hello world\n"
      ()
  }

  let _ = child.wait()
}

#Platform Compatibility

#WASM Limitations

#API Overview

• Command: The main entry point.
• Stdio: Configuration for input/output streams.
• Child: Handle to a running process.
• ExitStatus: Status code of a terminated process.