Effective memory mapping

mmap (or Memory Map) is the forbidden fruit of system programming. It promises the sweet nectar of raw memory access, bypassing those pesky layers of file I/O. But like anything that whispers the promise of power, mmap comes with a side of head-scratching complexity and a few potential landmines. Let’s dive in, shall we?

Imagine mmap as breaking down the walls of your local library. Instead of laboriously checking out books (or reading from files the boring way), you gain direct access to the whole darn collection. You can flip through those dusty volumes at lightning speed, finding exactly what you need without waiting for the nice librarian (your operating system’s filesystem). Sounds amazing, right?

It is a system call that creates a mapping between a file on disk and a block of memory in your program’s address space. Suddenly, those file bytes become just another chunk of memory for you to play with. This is awesome for huge files...