Linux Library Preload

This technique is effectively equivalent to Windows: Inject Into Suspended Process but officially supported at the OS level. Run the target process with LD_PRELOAD=path/to/your/library.so command args...

Summary: This is the only approach (I'm aware of) that can satisfy the constraint of executing custom code before game code. This is not possible with ptrace at least.

Issue: Spaces in Paths

Info

The LD_PRELOAD variable uses space as a directory delimiter to

If the path to the mod loader contains a space, the mod manager must create a Symlink for the file with a location where a space isn't present.

General Approach

• Read the current value of LD_PRELOAD.
• Create temporary symlink if path to mod loader contains space.
• Add mod loader library to value of LD_PRELOAD.
• Start the process.
• Restore original LD_PRELOAD value.