mmap_private(3)

💖 mmap_private — from the Library Functions Manual 💖

okay bestie, pull up a chair, because mmap_private(3) is literally about to hand you an entire file like it's a gift 🎁

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✨ NAME ✨

mmap_private — memory map a file for reading and writing 🦋

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✨ SYNTAX ✨

#include <libowfat/mmap.h>

char* mmap_private(const char* filename,size_t* filesize);

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✨ DESCRIPTION ✨

so here's the tea, and it is good tea ☕

mmap_private opens filename for reading, maps the whole file into memory, closes the file, writes the length of the file into filesize, and returns a pointer to that mapped file. that's it. that's the whole vibe. you get a pointer, you get a size, you go be the main character 👑

the file is mapped copy-on-write. so like… changes you make to the mapped region will not be written to disk. nope. not happening. your edits live in memory and stay in memory, no cap 🙈

when your process terminates, the operating system unmaps the file for you — automatic, no cleanup on your part, iconic behaviour honestly 💅

but if you're the type who likes to be in control (respect), you can also manually unmap it by calling munmap from <sys/mman.h>.

and if the file could not be opened or mapped? you get (void*)0 back. that's the "it's giving nothing" response 😭 always check for it, bestie, fr fr.

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✨ SEE ALSO ✨

• mmap_unmap(3)
• mmap_read(3)
• mmap_readat(3)
• mmap_shared(3)

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and that's a wrap on mmap_private(3) from the Library Functions Manual 🎀 mwah, go map something pretty, and remember: copy-on-write means the disk never finds out 🌸✨