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