How start process and read paramters from stdin input in dart?

Question

I want to implement follow code in dart and start V2ray

cat ~/.config/qv2ray/vcore/config.json | v2ray

This is Node.js implement:

const result = child_process.spawn("v2ray", [], { input: str });

I spent a whole day solving this problem, but still couldn’t solve it

Answer 1

Made an example on how you can do it:

import 'dart:convert';
import 'dart:io';

Future<void> main() async {
  final homeDir = getHomeDir();

  if (homeDir == null) {
    throw Exception('Could not find home directory on running platform!');
  }

  final process = await Process.start('v2ray', const []);
  final resultStdoutFuture = process.stdout
      .transform(const Utf8Decoder())
      .transform(const LineSplitter())
      .toList();

  await process.stdin
      .addStream(File('$homeDir/.config/qv2ray/vcore/config.json').openRead());
  await process.stdin.close();

  print('Process stopped with exit code: ${await process.exitCode}');
  print('Returned stdout:');
  (await resultStdoutFuture).forEach((logLine) => print('\t$logLine'));
}

String? getHomeDir() {
  final envVars = Platform.environment;

  if (Platform.isMacOS) {
    return envVars['HOME'];
  } else if (Platform.isLinux) {
    return envVars['HOME'];
  } else if (Platform.isWindows) {
    return envVars['UserProfile'];
  }
}