PawnPlus.IO is an addon for PawnPlus allowing manipulation of various I/O streams, files, and network sockets, both synchronously and asynchronously.
See the wiki for documentation.
Download the latest release for your platform to the "plugins" directory and add "PawnPlus.IO" (or "PawnPlus.IO.so" on Linux) to the plugins line in server.cfg.
Include PawnPlus.IO.inc in your Pawn program and you are done.
PawnPlus has to be active in order for this plugin to work.
Use Visual Studio to build the project on Windows, or make or make static on Linux. Requires GCC >= 4.9.