How to insert a command line to GUI applications

Question

I need to make a QT GUI application that will be able to run the command line batchs and commands. For example, ping, tcpdump, etc. ...

I would imagine it like this: The standard graphical window with the QTableView, some checkboxes, etc. ... with a component instance QPlainTextEdit. This component (QPlainTextEdit) will act as a command line, that will allow to enter commands and capture their output.

Is such a thing possible? How should this be done?

Answer 1

You can use QProcess for your purpose..

QProcess cmd;
cmd.start("cmd");

More details here..

http://www.qtcentre.org/threads/12757-QProcess-cmd

Answer 2

The main idea is to use QProcess for running commands. See the code below for demonstration.

Sync approach

QProcess process;

// If "command" is not in your path,
// use the corresponding relative or absolute path

process.start("command", QStringList()
                      << QString("-arg1")
                      << QString("arg2")
                      << QString("-arg3")
                      << QString("arg4"));

// Wait for it to start
if(!process.waitForStarted())
    return 0;

bool retval = false;
QByteArray buffer;
while ((retval = process.waitForFinished()));
    buffer.append(process.readAll());

if (!retval) {
    yourPlainTextEdit.appendPlainText(process.errorString());
} else {
    yourPlainTextEdit.appendPlainText(buffer);
}

Async approach

MyClass::MyClass(QQProcess *process, QObject *parent)
    : QObject(parent)
    , m_process(process)
{
    connect(m_process, SIGNAL(readyRead()), SLOT(handleReadyRead()));
    connect(m_process, SIGNAL(error(QProcess::ProcessError)), SLOT(handleError(QProcess::ProcessError)));
    connect(&m_timer, SIGNAL(timeout()), SLOT(handleTimeout()));

    m_timer.start(5000);
}

MyClass::~MyClass()
{
}

void MyClass::handleReadyRead()
{
    m_readData.append(m_process->readAll());

    if (!m_timer.isActive())
        m_timer.start(5000);
}

void MyClass::handleTimeout()
{
    if (m_readData.isEmpty()) {
        yourPlainTextEdit.appendPlainText("No data was currently available for reading from gnuplot");
    } else {
        yourPlainTextEdit.appendPlainText("Process successfully run");
    }

}

void GnuPlotReader::handleError(QProcess::ProcessError processError)
{
    if (processError == QProcess::ReadError) {
        appendPlainTextEdit.appendPlainText("An I/O error occurred while reading the data, error: %1").arg(m_process->errorString()));
        yourPlainTextEdit.appendPlainText(m_readData);
    }
}

Disclaimer: This is fully untested code, so it may have compiler and run time issues, but this should give a good grasp of it without further ado.