QProcessWatcher

Simple interface for monitoring state of process for Windows.

Use addProcess() method for add a process for monitoring by passing a case insensitive process name.

The signal processStarted() will be emitted in two cases:

1. If the monitored process is already started before calling addProcess() method.
2. When the first copy of process is started.

The signal processFinished() will be emitted when all copies of monitored process is closed.

You can define a PROCESS_WATCHER_DEBUG macro in project file for view a small debug information:

DEFINES += PROCESS_WATCHER_DEBUG

Usage

#include "qprocesswatcher.h"
...
QProcessWatcher watcher;
watcher.addProcess("MSPaint.exe");

Examples

Example 1

#include <QApplication>
#include <QWidget>
#include "qprocesswatcher.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    // Create widget
    QWidget w;

    // Create watcher and add monitoring for "MSPaint.exe" process
    QProcessWatcher watcher;
    watcher.addProcess("MSPaint.exe");

    // Connect signals
    QObject::connect(&watcher, SIGNAL(processStarted(QString,QString)), &w, SLOT(show()));
    QObject::connect(&watcher, SIGNAL(processFinished(QString)), &w, SLOT(close()));

    return a.exec();
}

This windget-based application wait for starting "MSPaint.exe" process and then shows the Widget form.
Widget has closed automatically when "MSPaint.exe" is closed.

Example 2

#include <QApplication>
#include <QMessageBox>
#include "qprocesswatcher.h"

void onProcessStarted(const QString &processName,
                      const QString &originalProcessName)
{
    const QString title = QObject::tr("Process started");
    const QString message = QObject::tr("Process `%1` is started with name `%2`!")
            .arg(processName)
            .arg(originalProcessName);

    QMessageBox::information(nullptr, title, message);
}

void onProcessFinished(const QString &processName)
{
    const QString title = QObject::tr("Process finished");
    const QString message = QObject::tr("Process `%1` is finished!")
            .arg(processName);

    QMessageBox::information(nullptr, title, message);
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    a.setQuitOnLastWindowClosed(false);

    QProcessWatcher watcher;
    watcher.addProcess("MSPaint.exe");
    watcher.addProcess("CMD.EXE");

    QObject::connect(&watcher, &QProcessWatcher::processStarted, &onProcessStarted);
    QObject::connect(&watcher, &QProcessWatcher::processFinished, &onProcessFinished);

    return a.exec();
}

This application shows information message when processes "MSPaint.exe" and "CMD.EXE" starts or finished.