dgamelaunch/io.c

147 lines
3.8 KiB
C

/*
* Copyright (c) 2000 Satoru Takabayashi <satoru@namazu.org>
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <errno.h>
#include "ttyrec.h"
#define SWAP_ENDIAN(val) ((unsigned int) ( \
(((unsigned int) (val) & (unsigned int) 0x000000ffU) << 24) | \
(((unsigned int) (val) & (unsigned int) 0x0000ff00U) << 8) | \
(((unsigned int) (val) & (unsigned int) 0x00ff0000U) >> 8) | \
(((unsigned int) (val) & (unsigned int) 0xff000000U) >> 24)))
static int
is_little_endian ()
{
static int retval = -1;
if (retval == -1)
{
int n = 1;
char *p = (char *) &n;
char x[] = { 1, 0, 0, 0 };
assert (sizeof (int) == 4);
if (memcmp (p, x, 4) == 0)
{
retval = 1;
}
else
{
retval = 0;
}
}
return retval;
}
static int
convert_to_little_endian (int x)
{
if (is_little_endian ())
{
return x;
}
else
{
return SWAP_ENDIAN (x);
}
}
int
read_header (FILE * fp, Header * h)
{
int buf[3];
int numread;
long offset;
offset = ftell (fp);
numread = fread (buf, sizeof (int), 3, fp);
/* odd but possible race condition when full header isn't read because
* it isn't there yet. */
if (numread < 3)
{
fseek (fp, offset, SEEK_SET);
return 0;
}
h->tv.tv_sec = convert_to_little_endian (buf[0]);
h->tv.tv_usec = convert_to_little_endian (buf[1]);
h->len = convert_to_little_endian (buf[2]);
return 1;
}
int
write_header (FILE * fp, Header * h)
{
int buf[3];
buf[0] = convert_to_little_endian (h->tv.tv_sec);
buf[1] = convert_to_little_endian (h->tv.tv_usec);
buf[2] = convert_to_little_endian (h->len);
if (fwrite (buf, sizeof (int), 3, fp) == 0)
{
return 0;
}
return 1;
}
static char *progname = "";
void
set_progname (const char *name)
{
progname = strdup (name);
}
FILE *
efopen (const char *path, const char *mode)
{
FILE *fp = fopen (path, mode);
if (fp == NULL)
{
fprintf (stderr, "%s: %s: %s\n", progname, path, strerror (errno));
exit (EXIT_FAILURE);
}
return fp;
}