io_prep_pwrite(3)

✨ io_prep_pwrite — the Linux AIO glow-up ✨

okay bestie, welcome to io_prep_pwrite(3), part of the Linux AIO crew 🦋 this is the little helper that gets your asynchronous writes ready to slay. no cap, it's giving backstage-pass energy — it sets everything up so the real show (io_submit) can happen later 💅

🌸 NAME 🌸

io_prep_pwrite — Set up iocb for asynchronous writes

🎀 SYNOPSIS 🎀

#include <errno.h>

#include <libaio.h>

inline void io_prep_pwrite(struct iocb *iocb, int fd, void *buf, size_t count, long long offset);

struct iocb {
     void      *data;
     unsigned  key;
     short          aio_lio_opcode;
     short          aio_reqprio;
     int       aio_fildes;
};

💖 DESCRIPTION 💖

io_prep_write() is literally a convenience function for setting up parallel writes. it's the "here, let me hold your stuff while you get ready" friend 🫶

so here's the tea: the first iocb->u.c.nbytes = count bytes of the file — the one where iocb->aio_fildes = fd is the descriptor — get written from the buffer starting at iocb->u.c.buf = buf. and the writing kicks off at the absolute position ioc->u.c.offset = offset in the file 📍

heads up: this function returns immediately. like, instantly. to actually schedule the operation you must call io_submit(3). no io_submit, no write. periodt 💀

🚨 also bestie, listen: simultaneous asynchronous operations using the same iocb produce undefined results. same iocb, two ops at once = chaos, and not the fun kind. don't do it 🙈

⭐ RETURN VALUES ⭐

None. nothing. niente. it just does its thing and dips ✨

🌈 ERRORS 🌈

None. zero drama, zero errors. it's the low-maintenance icon we deserve 👑

🦋 SEE ALSO 🦋

• io(3)
• io_cancel(3)
• io_fsync(3)
• io_getevents(3)
• io_prep_fsync(3)
• io_prep_pread(3)
• io_queue_init(3)
• io_queue_release(3)
• io_queue_run(3)
• io_queue_wait(3)
• io_set_callback(3)
• io_submit(3)
• errno(3)

and that's the whole page, bestie 💜 this one's from Linux, dated 2019-07-23 — so it's a lil vintage but it still ate, fr fr. go forth and io_submit responsibly 🧚💖