Deduplicate the environment variables values

Information

C dynamic library to add to LD_PRELOAD to clean environment variables that are duplicated. Both versions contains a list of environment variables that it is allowed to change. Add or remove according to your needs!

Static version

The static version cleans all environment variables every time

Dynamic version

The dynamic version cleans only the environment variable that is being changed

Usage

Build

• To build the static version use: gcc -shared -fPIC -o libenv_dedup.so env_dedup.c -ldl
• To build the dynamic version use: gcc -shared -fPIC -o libenv_dedup_dynamic.so env_dedup_dynamic.c -ldl
• To build the dynamic optimised version, use: gcc -shared -fPIC -O3 -D_GNU_SOURCE -o libenv_dedup_dynamic_optimised_o3.so env_dedup_dynamic_optimised.c -ldl

Apply

Add the dynamic library to LD_PRELOAD like this and test it: LD_PRELOAD=libenv_dedup_dynamic.so $app

If everything works

Consider adding exporting it on .bashrc or for KDE to ~/.config/plasma-workspace/env/00-env-dedup.sh

On NixOS

You can add: environment.variables.LD_PRELOAD = "/etc/nixos/libenv_dedup_dynamic.so"; to make it system wide. (adjust the location as needed)

Considerations

Please test carefully first before applying system wide

Development

This code was developed with the help of AI/LLM.