PhysicsFS is a library to provide abstract access to various archives. It is intended for use in video games, and the design was somewhat inspired by Quake 3's file subsystem. The programmer defines a "write directory" on the physical filesystem. No file writing done through the PhysicsFS API can leave that write directory, for security. For example, an embedded scripting language cannot write outside of this path if it uses PhysFS for all of its I/O, which means that untrusted scripts can run more safely.
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