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Annotation of dgamelaunch-openbsd/io.c, Revision 1.1

1.1     ! rubenllo    1: /*
        !             2:  * Copyright (c) 2000 Satoru Takabayashi <satoru@namazu.org>
        !             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:  * 3. All advertising materials mentioning features or use of this software
        !            14:  *    must display the following acknowledgement:
        !            15:  *     This product includes software developed by the University of
        !            16:  *     California, Berkeley and its contributors.
        !            17:  * 4. Neither the name of the University nor the names of its contributors
        !            18:  *    may be used to endorse or promote products derived from this software
        !            19:  *    without specific prior written permission.
        !            20:  *
        !            21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
        !            22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
        !            23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
        !            24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
        !            25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        !            26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
        !            27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        !            29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        !            30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        !            31:  * SUCH DAMAGE.
        !            32:  */
        !            33:
        !            34: #include <stdio.h>
        !            35: #include <stdlib.h>
        !            36: #include <assert.h>
        !            37: #include <string.h>
        !            38: #include <errno.h>
        !            39:
        !            40: #include "ttyrec.h"
        !            41:
        !            42: #define SWAP_ENDIAN(val) ((unsigned int) ( \
        !            43:     (((unsigned int) (val) & (unsigned int) 0x000000ffU) << 24) | \
        !            44:     (((unsigned int) (val) & (unsigned int) 0x0000ff00U) <<  8) | \
        !            45:     (((unsigned int) (val) & (unsigned int) 0x00ff0000U) >>  8) | \
        !            46:     (((unsigned int) (val) & (unsigned int) 0xff000000U) >> 24)))
        !            47:
        !            48: static int
        !            49: is_little_endian ()
        !            50: {
        !            51:   static int retval = -1;
        !            52:
        !            53:   if (retval == -1)
        !            54:     {
        !            55:       int n = 1;
        !            56:       char *p = (char *) &n;
        !            57:       char x[] = { 1, 0, 0, 0 };
        !            58:
        !            59:       assert (sizeof (int) == 4);
        !            60:
        !            61:       if (memcmp (p, x, 4) == 0)
        !            62:         {
        !            63:           retval = 1;
        !            64:         }
        !            65:       else
        !            66:         {
        !            67:           retval = 0;
        !            68:         }
        !            69:     }
        !            70:
        !            71:   return retval;
        !            72: }
        !            73:
        !            74: static int
        !            75: convert_to_little_endian (int x)
        !            76: {
        !            77:   if (is_little_endian ())
        !            78:     {
        !            79:       return x;
        !            80:     }
        !            81:   else
        !            82:     {
        !            83:       return SWAP_ENDIAN (x);
        !            84:     }
        !            85: }
        !            86:
        !            87: int
        !            88: read_header (FILE * fp, Header * h)
        !            89: {
        !            90:   int buf[3];
        !            91:   int numread;
        !            92:   long offset;
        !            93:
        !            94:   offset = ftell (fp);
        !            95:   numread = fread (buf, sizeof (int), 3, fp);
        !            96:
        !            97:   /* odd but possible race condition when full header isn't read because
        !            98:    * it isn't there yet. */
        !            99:   if (numread < 3)
        !           100:     {
        !           101:       fseek (fp, offset, SEEK_SET);
        !           102:       return 0;
        !           103:     }
        !           104:
        !           105:   h->tv.tv_sec = convert_to_little_endian (buf[0]);
        !           106:   h->tv.tv_usec = convert_to_little_endian (buf[1]);
        !           107:   h->len = convert_to_little_endian (buf[2]);
        !           108:
        !           109:   return 1;
        !           110: }
        !           111:
        !           112: int
        !           113: write_header (FILE * fp, Header * h)
        !           114: {
        !           115:   int buf[3];
        !           116:
        !           117:   buf[0] = convert_to_little_endian (h->tv.tv_sec);
        !           118:   buf[1] = convert_to_little_endian (h->tv.tv_usec);
        !           119:   buf[2] = convert_to_little_endian (h->len);
        !           120:
        !           121:   if (fwrite (buf, sizeof (int), 3, fp) == 0)
        !           122:     {
        !           123:       return 0;
        !           124:     }
        !           125:
        !           126:   return 1;
        !           127: }
        !           128:
        !           129: static char *progname = "";
        !           130: void
        !           131: set_progname (const char *name)
        !           132: {
        !           133:   progname = strdup (name);
        !           134: }
        !           135:
        !           136: FILE *
        !           137: efopen (const char *path, const char *mode)
        !           138: {
        !           139:   FILE *fp = fopen (path, mode);
        !           140:   if (fp == NULL)
        !           141:     {
        !           142:       fprintf (stderr, "%s: %s: %s\n", progname, path, strerror (errno));
        !           143:       exit (EXIT_FAILURE);
        !           144:     }
        !           145:   return fp;
        !           146: }