For Qt development I’m using Qt Creator which is freely available and combine designer and editor to one complex program.

First simple program which print some data to standard output.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main(void)
{
    unsigned i = 0;

    for ( ; ; ) {
        fprintf(stdout,"Value = %X\n", i++);
        fflush(stdout);
        sleep(2);
    }
    return 0;
}

For compiling use :

gcc -o test test.c

For reading stdout we use Qt signal readyStandardOutput() which is triggered when something is written to stdout.

In Qt Creator just create default Qt4 application.

Add to mainwindow.h:

private:
    Ui::MainWindowClass *ui;
    QProcess *process;

Methods and slot in mainwindow.cpp:

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

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindowClass)
{
    ui->setupUi(this);
    process = new QProcess(this);
    process->setReadChannel(QProcess::StandardOutput);
    connect(process, SIGNAL(readyReadStandardOutput()), this, SLOT(updateOutput()));
    process->start("./test");

}

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

void MainWindow :: updateOutput(void)
{
    QByteArray bytes = process->readAllStandardOutput();
    ui->textEdit->insertPlainText(bytes);
}

Thats all. When you run Qt application you should see all stdout in textEdit.

Marek