freebsd-dev/usr.sbin/kgzip/xio.c

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/*
* Copyright (c) 1999 Global Technology Associates, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
1999-08-28 01:35:59 +00:00
* $FreeBSD$
*/
#include <err.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include "kgzip.h"
/*
* Close a file.
*/
void
xclose(const struct iodesc *id)
{
if (close(id->fd))
err(1, "%s", id->fname);
}
/*
* Copy bytes from one file to another.
*/
void
xcopy(const struct iodesc * idi, const struct iodesc * ido,
size_t nbyte, off_t offset)
{
char buf[8192];
size_t n;
while (nbyte) {
if ((n = sizeof(buf)) > nbyte)
n = nbyte;
if (xread(idi, buf, n, offset) != n)
errx(1, "%s: Short read", idi->fname);
xwrite(ido, buf, n);
nbyte -= n;
offset = -1;
}
}
/*
* Write binary zeroes to a file.
*/
void
xzero(const struct iodesc * id, size_t nbyte)
{
char buf[8192];
size_t n;
memset(buf, 0, sizeof(buf));
while (nbyte) {
if ((n = sizeof(buf)) > nbyte)
n = nbyte;
xwrite(id, buf, n);
nbyte -= n;
}
}
/*
* Read from a file.
*/
size_t
xread(const struct iodesc * id, void *buf, size_t nbyte, off_t offset)
{
ssize_t n;
if (offset != -1 && lseek(id->fd, offset, SEEK_SET) != offset)
err(1, "%s", id->fname);
if ((n = read(id->fd, buf, nbyte)) == -1)
err(1, "%s", id->fname);
return (size_t)n;
}
/*
* Write to a file.
*/
void
xwrite(const struct iodesc * id, const void *buf, size_t nbyte)
{
ssize_t n;
if ((n = write(id->fd, buf, nbyte)) == -1)
err(1, "%s", id->fname);
if ((size_t)n != nbyte)
errx(1, "%s: Short write", id->fname);
}
/*
* Reposition within a file.
*/
void
xseek(const struct iodesc *id, off_t offset)
{
if (lseek(id->fd, offset, SEEK_SET) != offset)
err(1, "%s", id->fname);
}