mmap_readat(3)

✨ mmap_readat ✨

okay so bestie, this one lives in the Library Functions Manual and it's literally the "give me this whole file in memory, right now, no drama" function 💅

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🌸 NAME 🌸

mmap_readat — memory map a file for reading 🗺️✨

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🎀 SYNTAX 🎀

#include <libowfat/mmap.h>

const char* mmap_readat(const char* filename,size_t* filesize,int dirfd);

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🦋 DESCRIPTION 🦋

so here's the vibe: mmap_readat opens filename for reading, maps the entire file into memory, then closes the file. after that it writes the length of the file into filesize and hands you back a pointer to the mapped file. boom. whole file, right there, zero scrolling. 🔥

if filename is a relative path and dirfd is not AT_FDCWD (which is defined in fcntl.h, iykyk), then filename gets interpreted relative to dirfd — and dirfd must be an open directory. no cap, it has to be an actual open dir. 🙈

the file gets unmapped by the operating system all on its own when the process terminates (she's independent like that 💁). but if you wanna do it manually, you can call munmap from <sys/mman.h> — main character energy, taking things into your own hands.

and if the file could not be opened or mapped? you get (void*)0 back. not a vibe, but that's the deal. 😭

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👑 SEE ALSO 👑

• mmap_unmap(3)
• mmap_private(3)
• mmap_read(3)
• mmap_shared(3)

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that's the whole page bestie, mwah 💖 from the Library Functions Manual with love — go map something iconic 🎀✨