/usr/include/I2util/io.h is in libi2util-dev 1.2-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 | /*
 *      $Id: io.h 216 2012-10-16 19:57:01Z aaron $
 */
/************************************************************************
*									*
*			     Copyright (C)  2002			*
*				Internet2				*
*			     All Rights Reserved			*
*									*
************************************************************************/
/*
 *	File:		io.h
 *
 *	Author:		Jeff W. Boote
 *			Internet2
 *
 *	Date:		Fri Aug 09 12:53:52 MDT 2002
 *
 *	Description:	
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */
#ifndef	_i2_io_h_
#define	_i2_io_h_
#include <I2util/util.h>
#include <fcntl.h>
BEGIN_C_DECLS
extern ssize_t
I2Readni(
	int	fd,
	void	*vptr,
	size_t	n,
	int	*retn_on_intr	/* pointer so it can be modified via signals */
	);
extern ssize_t
I2Readn(
	int	fd,
	void	*vptr,
	size_t	n
	);
extern ssize_t
I2Writeni(
	int		fd,
	const void	*vptr,
	size_t		n,
	int		*retn_on_intr
	);
extern ssize_t
I2Writen(
	int		fd,
	const void	*vptr,
	size_t		n
	);
extern int
I2CopyFile(
        I2ErrHandle eh,
        int         tofd,
        int         fromfd,
        size_t      len
        );
END_C_DECLS
#endif	/*	_i2_io_h_	*/
 |