io_sendfile(3)

💖 io_sendfile(3) 💖

okay bestie, buckle up, this one's from the Library Functions Manual and it's literally the glow-up your file-to-socket pipeline has been begging for 🫶

✨ NAME ✨

io_sendfile — send data from a file to a socket 🦋

✨ SYNTAX ✨

#include <libowfat/io.h>

int64 io_sendfile(int64 sock,int64 fd,uint64 off,uint64 n);

✨ DESCRIPTION ✨

so io_sendfile sends data from a file to a socket. and not in a mid way either — it tries to do it in a way that lets high quality operating systems pull off zero-copy TCP 💅 which is the fancy way of saying it serves the data without copying the file contents to user space or inside kernel space. no extra copies, no nonsense, just vibes ✨

the way it works: this function will use special operating system "sendfile" primitives where available, and fall back to memory mapped I/O otherwise. either way?? it should always be faster than using read() and write() to copy the data yourself. like, not even close. main character energy fr fr 👑

and it tells you how it went:

• returns the number of bytes sent ✅
• if an error occurred, it returns -1 for EAGAIN, or -3 otherwise 😭

bestie pls actually check the return value, okay? -1 and -3 are two different little gremlins and you wanna know which one you got 🙈

✨ SEE ALSO ✨

• io_wait(3)
• io_waituntil(3)

that's the whole page, no cap 💜 this was io_sendfile(3) — straight out of the Library Functions Manual, footer and all, say hi to your sockets for me 🎀🌸