Question

我有一个简单的child_process.exec语句，其输出（stdout）由于某种原因在开头总是有一个“♀”字符

var exec = require('child_process').exec;
exec('echo hi', function (err, stdout) {
    console.log(stdout);
});

[ scr]

我的节点是v0.12，我也安装了iojs，这是v2.3。我已经单独测试了两个相同的结果。我也在不同的控制台测试它 - cmd.exe，powershell和Git的sh.exe，结果相同。

这个角色应该存在吗？如果没有，可能产生什么呢？

Answer 1

根据stdout documentation，传递给var exec = require('child_process').exec; var StringDecoder = require('string_decoder').StringDecoder; var decoder = new StringDecoder('utf8'); exec('echo hi', function (err, stdout) { var message = decoder.write(stdout); console.log(message.trim()); });的对象是缓冲对象。在将其作为字符串打印出来之前，您需要对其进行解码。

我修改了你的代码来演示如何做到这一点。该符号不再出现在我的控制台中。

public class MainActivity extends AppCompatActivity {

    public static final String EXTRA_MESSAGE = "com.nick.mowen.receiptmanager.LOCATION";
    public String Places[];
    public RecyclerView RV;
    private RVAdapter adapter;
    Cursor mCursor;
    ManagerDatabaseAdapter managerDatabaseAdapter;
    List<MainInfo> mainInfo = new ArrayList<MainInfo>();
    RecyclerView.LayoutManager layoutManager;
    private Context activity;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        managerDatabaseAdapter = new ManagerDatabaseAdapter(this);
        setContentView(R.layout.activity_main);
        adapter = new RVAdapter(getActivity(), managerDatabaseAdapter.getTheCursor());
        RV = (RecyclerView) findViewById(R.id.mainV);
        layoutManager = new LinearLayoutManager(getActivity());
        RV.setLayoutManager(layoutManager);
        RV.setAdapter(adapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
      //  getMenuInflater().inflate(R.menu.menu_main, li)
        return true;
    }

    public static void getData () {

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            Intent intent = new Intent(this,SettingsActivity.class);
            intent.putExtra(EXTRA_MESSAGE,true);
            startActivity(intent, ActivityOptions.makeSceneTransitionAnimation(this).toBundle());
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /*@Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        TextView userText= (TextView) view;
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }*/

    public void addInstance(View view) {
        Intent intent = new Intent(this,LocationAdder.class);
        intent.putExtra(EXTRA_MESSAGE,true);
        startActivity(intent, ActivityOptions.makeSceneTransitionAnimation(this).toBundle());
    }

    public Context getActivity() {
        return activity;
    }
}

有关字符串解码器的更多详细信息，您可以随时查看文档here

child_process.exec生成“♀”字符

1 个答案: