Qt：如何获取正在运行的QProcess的实时输出

问题描述

我必须在运行时获取QProcess的输出。因此，我写了以下代码：

  CommandExecutor_C :: CommandExecutor_C（）：
 mProcessStatus（AI_UNKNOWN），
 mOnTdiActiveCallback（），
 mTdiProcess（new QProcess）
 {
 connect（mTdiProcess，SIGNAL（readyReadStandardOutput（）），this，SLOT（CheckOutput 
 connect（mTdiProcess，SIGNAL（readyReadStandardError（）），this，SLOT（CheckOutput（）））; 
} 
 
 void CommandExecutor_C :: ExecuteCommand（QString& aCommand）
 {
 mTdiProcess-> start（aCommand，QProcess :: Unbuffered | QProcess :: ReadWrite ）; 
 LOGINFO（FB_TDI，Launch command：+ aCommand.toStdString（））; 
} 
 
 
 void CommandExecutor_C :: CheckOutput（）
 {
 QString StdOut = QString（mTdiProcess-> readAllStandardOutput（））; 
 QString StdErr = QString（mTdiProcess-> readAllStandardError（））; 
 
 mProcessStatus = CheckTdiAutomationInterface（StdOut.toStdString（），StdErr.toStdString（））; 
 
 if（mProcessStatus！= AI_UNKNOWN）
 {
 OnTdiActive（mProcessStatus）; 
} 
} 
  

如果QProcess完成，该过程启动一个应该在后台永久运行的自动化接口。因此，我使用readyReadStandardOutput并将其连接到插槽CheckOutput（）。 CheckOutput（）正在进程被调用，如果进程已经完成。否则我在等待无休止。

我已经搜索了很多关于这个问题，但没有什么工作。我非常确定输出是缓冲，只是返回如果进程已经完成。因此我已经启动了处于非缓冲模式的进程。我也试图转发mTdiProcess的通道。代码：

  void CommandExecutor_C :: ExecuteCommand（QString& aCommand）
 {
 mTdiProcess- > setProcessChannelMode（QProcess :: ForwardedChannels）; 
 mTdiProcess-> start（aCommand，QProcess :: Unbuffered | QProcess :: ReadWrite）; 
 LOGINFO（FB_TDI，Launch command：+ aCommand.toStdString（））; 
} 
  

但没有用。

解决问题。

如果这很重要，我使用Qt 5.4.2。方案

我通常以如下的定期检查输出：

  bool returnBool = false; 
 while（returnBool = false）
 {
 / *！如果进程完成，请等待一秒钟。然后读取所有输出到
 * stdout和stderr和重做。 * / 
 returnBool = process.waitForFinished（1000）; 
 QString outputStdOut = process.readAllStandardOutput（）; 
 QString outputStdErr = process.readAllStandardError（）; 
} 
  

I have to get the output of a QProcess while it is running. Therefore I have written the following Code:

CommandExecutor_C::CommandExecutor_C():
  mProcessStatus(AI_UNKNOWN),
  mOnTdiActiveCallback(),
  mTdiProcess(new QProcess)
{
    connect(mTdiProcess, SIGNAL(readyReadStandardOutput()), this, SLOT(CheckOutput()));
    connect(mTdiProcess, SIGNAL(readyReadStandardError()), this, SLOT(CheckOutput()));
}

void CommandExecutor_C::ExecuteCommand(QString &aCommand)
{
  mTdiProcess->start(aCommand, QProcess::Unbuffered | QProcess::ReadWrite);
  LOGINFO(FB_TDI,"Launch command: " + aCommand.toStdString());
}


void CommandExecutor_C::CheckOutput()
{
    QString StdOut = QString(mTdiProcess->readAllStandardOutput());
    QString StdErr = QString(mTdiProcess->readAllStandardError());

    mProcessStatus = CheckTdiAutomationInterface(StdOut.toStdString(), StdErr.toStdString());

    if(mProcessStatus != AI_UNKNOWN)
    {
      OnTdiActive(mProcessStatus);
    }
}

This works fine if QProcess gets finished but in my case the Process starts an automation interface which should run in background permanently. Therefore I have used "readyReadStandardOutput" and connect it to the slot CheckOutput(). CheckOutput() is getting called just if the process has been finished. Otherwise I am waiting endless.

I have googled a lot about the problem but nothing worked. I am very sure that the output is getting buffered and does just return if the Process has finished. Therefore I have started the Process in Unbuffered-Mode. I have also tried to forward the channels of mTdiProcess. Here the Code:

void CommandExecutor_C::ExecuteCommand(QString &aCommand)
{
  mTdiProcess->setProcessChannelMode(QProcess::ForwardedChannels);
  mTdiProcess->start(aCommand, QProcess::Unbuffered | QProcess::ReadWrite);
  LOGINFO(FB_TDI,"Launch command: " + aCommand.toStdString());
}

But nothing worked. I hope you can help me.

I am using Qt 5.4.2 if that's important.

解决方案

I usually check the output in regular intervals like this:

bool returnBool = false;
while (returnBool == false)
{
    /*! Wait one second if the process finishes. Then read all output to
     * stdout and stderr and redo. */
    returnBool = process.waitForFinished(1000);
    QString outputStdOut = process.readAllStandardOutput();
    QString outputStdErr = process.readAllStandardError();
}

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