To add a gnome application menu item or so-called "
Desktop Entry" the following procedure can be used (I did it in CentOS5.2). Lets assume that we want to add menu item for Octave. First, as a root create file octave.desktop in /usr/share/applications/ with the following contents:
[Desktop Entry]
Name=Octave 3
Comment=Octave instead of Matlab
Categories=Application;
Exec=octave
Terminal=true
Type=Application
Icon=octave.png
Encoding=UTF-8
StartupNotify=true
octave.png icon can be created manually. Just find some octave logo imagee, convert it to png of size of 48x48 pixels and place it in folder /usr/share/pixmaps/. Of course it is not necessary, if icon does not exist gnome will not display any icon, only Name.
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The advantage of this procedure is that menu entry created will be available for every user, not only for root.