Qt5 Hello World on CentOS from command line with gcc

Install the libraries (I assume you have already installed gcc 4.8.x & friends on your system):

The Qt5 (pronounced as cute-five) base components

sudo yum install qt5-qtbase* 

sudo yum install mesa-libGL-devel -y

Create your project's folder: 

>>mkdir hello_world_qt

>>cd hello_world_qt 

Write hello word C++ file:

>> vi hello_world_qt.cpp

with content: 

#include <QtWidgets/QApplication>
#include <QtWidgets/QPushButton>
 
int main(int argc, char **argv)
{
 QApplication app (argc, argv);
 
 QPushButton button ("Hello world !");
 button.show();
 
 return app.exec();
}

then make a qt project with qmake:

>>qmake-qt5 -project

edit the *new* file hello_world_qt.pro by adding the line QT += widgets before TEMPLATE. The final file will look similar to this:

######################################################################
# Automatically generated by qmake (3.0) Sun Feb 7 15:13:47 2016
######################################################################

QT += widgets

TEMPLATE = app
TARGET = hello2
INCLUDEPATH += .

# Input
SOURCES += hello_world_qt.cpp

Now generate the Makefile with qmake:

>>qmake-qt5 -makefile

Finally, you can compile your program:

>>make 

and run it!

>>./hello_world_qt

------------------------------------------------------- 

NOTE: I ended up with this solution because I got the errors below (missing libraries) 

/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:20: undefined reference to `QApplication::QApplication(int&, char**, int)'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:22: undefined reference to `QPushButton::QPushButton(QString const&, QWidget*)'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:23: undefined reference to `QWidget::show()'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:25: undefined reference to `QApplication::exec()'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:22: undefined reference to `QPushButton::~QPushButton()'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:25: undefined reference to `QApplication::~QApplication()'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:25: undefined reference to `QApplication::~QApplication()'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:22: undefined reference to `QPushButton::~QPushButton()'
/home/eddie/QT_HOME/hello_world_qt/hello_world_qt.cpp:22: undefined reference to `QPushButton::~QPushButton()'
collect2: error: ld returned 1 exit status 

Sources for this post:

https://csl.name/post/qt-gcc/

http://stackoverflow.com/