What it is:
PDFedit is free and open source library for manipulating PDF
documents, released under terms of GNU GPL version 2. It includes PDF
manipulating library based on xpdf, GUI and set of command line tools.
PDFedit GUI is based on the Qt 3 toolkit and scripting engine (QSA),
so every operation is scriptable. Part of the program is also command
line interface for PDF manipulation.
To know more about:
sudo apt-get install pdfedit