.\" Copyright (c) 2022 by Alejandro Colomar <alx@kernel.org>
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.\"
.TH epoll_event 3type 2022-10-30 "Linux man-pages 6.03"
.SH NAME
epoll_event, epoll_data, epoll_data_t
\- epoll event
.SH LIBRARY
Standard C library
.RI ( libc )
.SH SYNOPSIS
.EX
.B #include <sys/epoll.h>
.PP
.B struct epoll_event {
.BR "    uint32_t      events;" "  /* Epoll events */"
.BR "    epoll_data_t  data;" "    /* User data variable */"
.B };
.PP
.B union epoll_data {
.B "    void     *ptr;"
.B "    int       fd;"
.B "    uint32_t  u32;"
.B "    uint64_t  u64;"
.B };
.PP
.B "typedef union epoll_data  epoll_data_t;"
.EE
.SH DESCRIPTION
The
.I epoll_event
structure specifies data that the kernel should save and
return when the corresponding file descriptor becomes ready.
.SH STANDARDS
This type is Linux-specific.
.SH NOTES
.SS C library/kernel differences
The Linux kernel headers also provide this type,
with a slightly different definition:
.PP
.in +4n
.EX
#include <linux/eventpoll.h>

struct epoll_event {
    __poll_t  events;
    __u64     data;
};
.EE
.in
.SH SEE ALSO
.BR epoll_wait (2),
.BR epoll_ctl (7)