The clipboard system in Linux (X11 to be more specific) recives complaints from users who expect it to work differently when applications are closed. The problem is that when content is copied from an application and the application is closed, the clipboard item will be cleared. I ran into this problem recently.
An easy way to fix this issue is to use a clipboard manager. The two most well-known clipboard managers for GNOME are Parcellite and Glipper.
Parcellite is not available in the Ubuntu 8.04 repositories, and the version in 8.10 is out of date. Packages for both versions of Ubuntu are available in a PPA. Follow this link to the packages, scroll down to the Packages section, and click the expand arrow for the Hardy or Intrepid package. Under Download files from Librarian select the Deb package for your CPU architecture.
Start Parcellite from Applications->Accessories->Parcellite. The application’s icon will appear in the notification area. Left click to open the menu of recently copied items, select an item to make it the current item in the clipboard. Right click to access the preferences.
If you close an application with copied text, the clipboard will still be cleared. You’ll have to open Parcellite and reselect the text from the history.
The latest version of Glipper is available in the Ubuntu 8.04 and 8.10 repositories. Install Glipper from the package glipper (click the link to install), or by running the command below in your terminal:
sudo apt-get install glipper
Don’t go looking for a menu item; instead of a standalone application, Glipper is an applet for the GNOME panel. Right click on your panel and select Add to panel. Select Clipboard Manager and click Add.
Left click on Glipper to open the list of recently copied text. Select a previous item to make it the active selection again. Right click to access the preferences.
Along with the traditional clipboard, Glipper also tracks any text which is selected. This clutters the history quickly so I turned it off. Deselect the Select clipboard in Glipper’s options to do this.
Copying text from an application and closing it is no trouble with Glipper. Just paste as you normally would, and the text will still be available.
Parcellite is lighter-weight, being written in C rather than Python like Glipper, and is also under much more active development. However I’ll be using Glipper until Parcellite can also automatically re-select the previous item on the clipboard after the copying application is closed.