Execing Processes in Dart

Here’s the translation of the Go code to Dart, with explanations in Markdown format suitable for Hugo:

In this example, we’ll look at executing external processes in Dart. Sometimes we want to completely replace the current Dart process with another one. To do this, we’ll use Dart’s implementation of process execution.

import 'dart:io';

void main() async {
  // For our example we'll execute 'ls'. Dart doesn't require an
  // absolute path to the binary we want to execute, so we can
  // directly use 'ls'.
  String binary = 'ls';

  // Process.run requires arguments in list form.
  // We'll give 'ls' a few common arguments.
  List<String> args = ['-a', '-l', '-h'];

  try {
    // Here's the actual Process.run call. This will execute
    // the 'ls' command with the specified arguments.
    ProcessResult result = await Process.run(binary, args);

    // If the execution is successful, we'll print the output.
    if (result.exitCode == 0) {
      print(result.stdout);
    } else {
      print('Error: ${result.stderr}');
    }
  } catch (e) {
    print('Failed to execute process: $e');
  }
}

When we run our program, it will execute the ls command and print its output.

$ dart run execing_processes.dart
total 16
drwxr-xr-x  4 user 136B Oct 3 16:29 .
drwxr-xr-x 91 user 3.0K Oct 3 12:50 ..
-rw-r--r--  1 user 1.3K Oct 3 16:28 execing_processes.dart

Note that Dart doesn’t offer a direct equivalent to Unix’s exec system call, which replaces the current process. Instead, Dart provides methods to spawn new processes and capture their output, which covers most use cases for process execution.

In Dart, we use Process.run() or Process.start() to execute external processes. The run() method is simpler and returns the result after the process completes, while start() gives more control over the process execution and allows for streaming input and output.

Dart also doesn’t have a direct equivalent to Go’s syscall.Exec. If you need to replace the current process entirely, you might need to use platform-specific code or consider restructuring your application.