Software linking

This small repository highlights some differences between dynamic and static linking.

The main difference between the two is that with dynamic linking a user has the option to dynamically choose which library to use at the time of execution. For the static linking the choice of library is determined at compile time.

In this repository there are several directories.

• fortran
  Contains a fortran source code which highlights the differences of linking with compiled code.
• package
  contains code for scripting languages. In particular a playground package and some examples of how to run code.
• python
  Contains a python source code which is a scripting language. Here there is per see not any linking taking place.

Dynamic or Static?

All programs you are using on your computer have likely been compiled at some point in time, and they are generally using dynamic/shared linking.

The difference between static and dynamic linking can be explained with an analogy of how person A shares a document to person B.

• Static
  Person A will send the document to person B (e.g. as an attachment by email).

• Dynamic
  Person A will send a link to the document to person B (e.g. person B does not have the document). For example SharePoint or Google Docs.

The difference in this case is obvious. When sharing a link, person A has the possibility of updating the document, without having to resend it to person B. Additionally there is no duplication of data. The document only lives one place. However, if person A accidentally deletes the document, then it will be lost, and the context in which the document was used will be lost.
With static linking one ensures that person B has complete knowledge at the time of receiving the document. This at the cost of having to request a new document if it changes, and at the cost of duplicating data.

This analogy is directly transferable to the software eco-system.

Accessing the DTU HPC infrastructure

The examples and playground will be done on the DTU HPC infrastructure.

All DTU employees have access to our HPC infrastructure.

Please go to https://thinlinc.gbar.dtu.dk and login using your regular DTU credentials.

There, you'll have access to a Linux distribution, and will have access to all the software all employees and students have access to.

Getting this source repository

Open up a terminal and execute the following:

git clone https://github.com/dtudk/software-linking.git

License

software-linking © 2025 by Nick Papior, Technical University of Denmark is licensed under CC BY-SA 4.0