mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <unistd.h>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QObject::connect(ui->pushButton, SIGNAL(clicked(bool)), this, SLOT(myfork()));
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::myfork()
{
    int status;
    pid_t pid1;

    if (( pid1 = fork() ))
    {
        /* parent process A */
        // waitpid(pid1, &status, 0);
    }
    else if ( !pid1 )
    {
        execl("/bin/ls", "ls", 0);
    }

}