The C and C++ Include Header Files

/usr/include/x86_64-linux-gnu/bits/poll.h


$ cat -n /usr/include/x86_64-linux-gnu/bits/poll.h

     1	/* Copyright (C) 1997-2024 Free Software Foundation, Inc.
     2	   This file is part of the GNU C Library.
     3	
     4	   The GNU C Library is free software; you can redistribute it and/or
     5	   modify it under the terms of the GNU Lesser General Public
     6	   License as published by the Free Software Foundation; either
     7	   version 2.1 of the License, or (at your option) any later version.
     8	
     9	   The GNU C Library is distributed in the hope that it will be useful,
    10	   but WITHOUT ANY WARRANTY; without even the implied warranty of
    11	   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    12	   Lesser General Public License for more details.
    13	
    14	   You should have received a copy of the GNU Lesser General Public
    15	   License along with the GNU C Library; if not, see
    16	   <https://www.gnu.org/licenses/>.  */
    17	
    18	#ifndef _SYS_POLL_H
    19	# error "Never use <bits/poll.h> directly; include <sys/poll.h> instead."
    20	#endif
    21	
    22	/* Event types that can be polled for.  These bits may be set in `events'
    23	   to indicate the interesting event types; they will appear in `revents'
    24	   to indicate the status of the file descriptor.  */
    25	#define POLLIN		0x001		/* There is data to read.  */
    26	#define POLLPRI		0x002		/* There is urgent data to read.  */
    27	#define POLLOUT		0x004		/* Writing now will not block.  */
    28	
    29	#if defined __USE_XOPEN || defined __USE_XOPEN2K8
    30	/* These values are defined in XPG4.2.  */
    31	# define POLLRDNORM	0x040		/* Normal data may be read.  */
    32	# define POLLRDBAND	0x080		/* Priority data may be read.  */
    33	# define POLLWRNORM	0x100		/* Writing now will not block.  */
    34	# define POLLWRBAND	0x200		/* Priority data may be written.  */
    35	#endif
    36	
    37	#ifdef __USE_GNU
    38	/* These are extensions for Linux.  */
    39	# define POLLMSG	0x400
    40	# define POLLREMOVE	0x1000
    41	# define POLLRDHUP	0x2000
    42	#endif
    43	
    44	/* Event types always implicitly polled for.  These bits need not be set in
    45	   `events', but they will appear in `revents' to indicate the status of
    46	   the file descriptor.  */
    47	#define POLLERR		0x008		/* Error condition.  */
    48	#define POLLHUP		0x010		/* Hung up.  */
    49	#define POLLNVAL	0x020		/* Invalid polling request.  */