you can do it by editing the file located at .local/share/applications/mimeapps.list and this file looks like this
according to my settings
[Default Applications]
text/x-python=geany.desktop
text/html=geany.desktop
[Added Associations]
text/x-python=geany.desktop;
text/html=geany.desktop;
and you can change the opening of the html files using aptana editing the mimeapps.list as
text/html=aptana.desktop
if there's aptana.desktop in /usr/share/applications
for creating .desktop file go to
/usr/share/applications
- open any applications with
gedit
they should look like this
[Desktop Entry]
Name=System Settings
Icon=preferences-system
Exec=unity-control-center --overview
Terminal=false
Type=Application
StartupNotify=true
Categories=GNOME;GTK;System;
OnlyShowIn=Unity;
Keywords=Preferences;Settings;
X-Ubuntu-Gettext-Domain=unity-control-center
then change these settings for aptana studio
for eg:
[Desktop Entry]
Icon=<location of icon>
Terminal=false
Type=Application
Exec=<location of aptana studio executive file>
and you don't have to save it in /usr/share/applications, you can save it in .local/share/applications/