epoll_event(3type)

✨ epoll_event(3type) — the epoll event glow-up ✨

okay bestie, listen. this is epoll_event(3type). also known as epoll_event, epoll_data, and epoll_data_t — they all ride together in this one lil manpage, and it's giving "three names, one vibe." 🎀

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📚 LIBRARY

Standard C library — aka libc. she's the moment. 💅

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🌸 SYNOPSIS

like, here's literally what you're working with, no cap:

#include <sys/epoll.h>

struct epoll_event {
    uint32_t      events;  /* Epoll events */
    epoll_data_t  data;    /* User data variable */
};

union epoll_data {
    void     *ptr;
    int       fd;
    uint32_t  u32;
    uint64_t  u64;
};

typedef union epoll_data  epoll_data_t;

look at her. iconic. 🦋

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💖 DESCRIPTION

so the epoll_event structure is the lil container that specifies data that the kernel should save and return when the corresponding file descriptor becomes ready. that's it. that's the whole job. she's a note the kernel keeps for you and hands back when the fd is finally ready to party. ✨

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🫶 VERSIONS

🧚 C library/kernel differences

plot twist bestie — the Linux kernel headers also provide this type, but with a slightly different definition. (not me having two versions of the same struct 😭):

#include <linux/eventpoll.h>

struct epoll_event {
    __poll_t  events;
    __u64     data;
};

so like. same girl, different outfit. don't get them confused or you'll be crying at 3am. 💀

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👑 STANDARDS

Linux. that's it. she's Linux-only, main character energy, periodt. 🌈

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🎀 SEE ALSO

• epoll_wait(2)
• epoll_ctl(2)

go read those next, they're the rest of the story, iykyk. 🔥

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and that's a wrap, bestie — this page came straight out of Linux man-pages 6.20, dated 2025-05-17. mwah. 💖✨🦋