An example ERROR message of running GUI applications written in Qt toolkit in Ubuntu

ERROR: (python:52708): Gtk-CRITICAL **: IA__gtk_widget_style_get: assertion 'GTK_IS_WIDGET (widget)' failed One solution to this error is installing qt4-qtconfig, a Qt 4 configuration tool

#install
sudo apt-get install qt4-qtconfig
# run the configuration
qtconfig
#config
#In the Appearance tab of the Qt Configuration application, locate "Select GUI Style" menu and choose "Plastique" option from drop down list.
#Save and exit

Linux: Run process as background and never dies

When you run your process from Putty SSH and the process will die after a certain time's inactivity of PuTTY terminal. Here is a simple solution to avoid lose your work:

nohup python start.py &

Note: Please do not start a web server command from putty terminal with & at the end of the command. THE FOLLOWING MAY CAUSE unexpected website behave PROBLEM:<

command_to_start_a_web_server &