Writing commands on linux terminal using Qt - c++

Question

I'm trying to get Qt creator to print a user input by using a push button on an UI into the terminal. As of now, the code is executable on the terminal via human input. Here is the code:
void MainWindow::on_pushButton_clicked()
{
QProcess::execute("/catkin_ws/devel/lib/submodbus");
system("cd catkin_ws/devel/lib/submodbus");
system("./submodbus_node");
}
Current output when using the code
Output via human input
The versions i'm running on are:
-Ubuntu 16.04
-QT Creator 3.5.1

Answer 1

system can't change the current directory globally. but could use like this:
system("cd /catkin_ws/devel/lib/submodbus && ./submodbus_node");
or using QProcess::setProgram with QProcess::setWorkingDirectory
QProcess p;
p.setProgram("submodbus_node");
//p.setArguments(QStringList()<<args); // if you need
p.setWorkingDirectory("/catkin_ws/devel/lib/submodbus");
p.start();
or QDir::setCurrent
QDir::setCurrent("/catkin_ws/devel/lib/submodbus");
QProcess::startDetached("submodbus_node");
Test demo, create three files in the parent directory:
#include <QApplication>
#include <QProcess>
#include <QDir>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
system("cd ../ && touch test1.txt");
QProcess p;
p.setProgram("touch");
p.setArguments(QStringList()<<"test2.txt");
p.setWorkingDirectory("../");
p.start();
QDir::setCurrent("../");
QProcess::startDetached("touch test3.txt");
return a.exec();
}