LD_PRELOAD

LD_PRELOAD is used by Linux to intercept functions in a program and replace their implementation with a custom implementation. One use case that comes up in HPC is the interception of I/O interfaces such as POSIX and routing their I/O commands to a custom filesystem.

LD_PRELOAD is organized as a colon-separated list.

export LD_PRELOAD="/path1:/path2:/path3"

LD_PRELOAD contains three paths in this example.