Qt|Linux工作笔记-第二种方式读取Linux中top命令（直接读取，非重定向）_8622qt top

第一种方式的链接如下：

https://mp.csdn.net/postedit/84067805

第一种方式是重定向到文件，然后读取，

第二种方式不重定向到文件，直接读取！

利用QProcess的特点

运行截图如下：

源码如下：

widget.h

#ifndef WIDGET_H
#define WIDGET_H
 
#include <QWidget>
 
QT_BEGIN_NAMESPACE
class QProcess;
QT_END_NAMESPACE
 
namespace Ui {
class Widget;
}
 
class Widget : public QWidget
{
    Q_OBJECT
 
public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();
 
protected:
    void callTopShell();
    void initListWidget();
 
protected slots:
    void readProcess();
    void processFinished();
 
private:
    Ui::Widget *ui;
    QProcess *m_topProcess;
};
 
#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"
 
#include <QProcess>
#include <QEventLoop>
#include <QTimer>
#include <QDebug>
 
 
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    m_topProcess = new QProcess;
    callTopShell();
    connect(m_topProcess, SIGNAL(readyRead()), this, SLOT(readProcess()));
    connect(m_topProcess, SIGNAL(finished(int,QProcess::ExitStatus)),this, SLOT(processFinished()));
    initListWidget();
}
 
Widget::~Widget()
{
    delete ui;
}
 
void Widget::callTopShell()
{
    QString cmdTop = "top -b -n 1";
    m_topProcess->start(cmdTop);
}
 
void Widget::processFinished(){
    qDebug()<< "process Finished";
 
    QEventLoop loop;
    QTimer::singleShot(0.2 * 1000, &loop, SLOT(quit()));
    loop.exec();
 
    initListWidget();
    callTopShell();
}
 
 
void Widget::initListWidget()
{
    ui->textEdit->clear();
}
 
void Widget::readProcess()
{
    qDebug()<< "readProcess called!";
    //qDebug()<< m_topProcess->readAll();
    ui->textEdit->insertPlainText(m_topProcess->readAll());
}

main.cpp

#include "widget.h"
#include <QApplication>
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();
 
    return a.exec();
}