1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Global Technology Associates, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
21 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
22 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
23 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
25 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
26 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/11/usr.sbin/kgzip/xio.c 330449 2018-03-05 07:26:05Z eadler $
29 */
30
31#include <err.h>
32#include <string.h>
33#include <unistd.h>
34
35#include "kgzip.h"
36
37/*
38 * Close a file.
39 */
40void
41xclose(const struct iodesc *id)
42{
43    if (close(id->fd))
44	err(1, "%s", id->fname);
45}
46
47/*
48 * Copy bytes from one file to another.
49 */
50void
51xcopy(const struct iodesc * idi, const struct iodesc * ido,
52      size_t nbyte, off_t offset)
53{
54    char buf[8192];
55    size_t n;
56
57    while (nbyte) {
58	if ((n = sizeof(buf)) > nbyte)
59	    n = nbyte;
60	if (xread(idi, buf, n, offset) != n)
61	    errx(1, "%s: Short read", idi->fname);
62	xwrite(ido, buf, n);
63	nbyte -= n;
64	offset = -1;
65    }
66}
67
68/*
69 * Write binary zeroes to a file.
70 */
71void
72xzero(const struct iodesc * id, size_t nbyte)
73{
74    char buf[8192];
75    size_t n;
76
77    memset(buf, 0, sizeof(buf));
78    while (nbyte) {
79	if ((n = sizeof(buf)) > nbyte)
80	    n = nbyte;
81	xwrite(id, buf, n);
82	nbyte -= n;
83    }
84}
85
86/*
87 * Read from a file.
88 */
89size_t
90xread(const struct iodesc * id, void *buf, size_t nbyte, off_t offset)
91{
92    ssize_t n;
93
94    if (offset != -1 && lseek(id->fd, offset, SEEK_SET) != offset)
95	err(1, "%s", id->fname);
96    if ((n = read(id->fd, buf, nbyte)) == -1)
97	err(1, "%s", id->fname);
98    return (size_t)n;
99}
100
101/*
102 * Write to a file.
103 */
104void
105xwrite(const struct iodesc * id, const void *buf, size_t nbyte)
106{
107    ssize_t n;
108
109    if ((n = write(id->fd, buf, nbyte)) == -1)
110	err(1, "%s", id->fname);
111    if ((size_t)n != nbyte)
112	errx(1, "%s: Short write", id->fname);
113}
114
115/*
116 * Reposition within a file.
117 */
118void
119xseek(const struct iodesc *id, off_t offset)
120{
121    if (lseek(id->fd, offset, SEEK_SET) != offset)
122	err(1, "%s", id->fname);
123}
124