File: [local] / src / usr.bin / compress / nullopen.c (download)
Revision 1.1, Fri Sep 5 06:08:15 2003 UTC (20 years, 9 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_3_4_BASE, OPENBSD_3_4
we kind of need this new file from canacar
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/* $OpenBSD: nullopen.c,v 1.1 2003/09/05 06:08:15 deraadt Exp $ */
/*
* Copyright (c) 2003 Can Erkin Acar
* Copyright (c) 1997 Michael Shalayeff
* 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 ``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 REGENTS 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.
*
*/
const char null_rcsid[] =
"$OpenBSD: nullopen.c,v 1.1 2003/09/05 06:08:15 deraadt Exp $";
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include "compress.h"
typedef struct {
off_t total_in;
off_t total_out;
int fd;
int gotmagic;
char mode;
} null_stream;
char null_magic[2];
void *
null_open(int fd, const char *mode, char *name, int bits,
u_int32_t mtime, int gotmagic)
{
null_stream *s;
if (fd < 0 || !mode)
return NULL;
if ((mode[0] != 'r' && mode[0] != 'w') || mode[1] != '\0') {
errno = EINVAL;
return NULL;
}
if ((s = (null_stream *) calloc(1, sizeof(null_stream))) == NULL)
return NULL;
s->fd = fd;
s->gotmagic = gotmagic;
s->total_in = s->total_out = 0;
s->mode = mode[0];
return s;
}
int
null_close(void *cookie, struct z_info *info)
{
null_stream *s = (null_stream*) cookie;
int err = 0;
if (s == NULL)
return -1;
if (info != NULL) {
info->mtime = 0;
info->crc = (u_int32_t)-1;
info->hlen = 0;
info->total_in = (off_t) s->total_in;
info->total_out = (off_t) s->total_out;
}
err = close(s->fd);
free(s);
return err;
}
int
null_flush(void *cookie, int flush)
{
null_stream *s = (null_stream*)cookie;
size_t len;
int done = 0;
int err;
if (s == NULL || s->mode != 'w') {
errno = EBADF;
return (-1);
}
return 0;
}
int
null_read(void *cookie, char *buf, int len)
{
null_stream *s = (null_stream*)cookie;
if (s == NULL) {
errno = EBADF;
return (-1);
}
if (s->gotmagic) {
if (len < 2) {
errno = EBADF;
return (-1);
}
buf[0] = null_magic[0];
buf[1] = null_magic[1];
s->gotmagic = 0;
return (2);
}
return read(s->fd, buf, len);
}
int
null_write(void *cookie, const char *buf, int len)
{
null_stream *s = (null_stream*)cookie;
if (s == NULL) {
errno = EBADF;
return (-1);
}
return write(s->fd, buf, len);
}