src/tests/read-write.c

   1 /*
   2  * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 #endif
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <sys/types.h>
  41 #include <fcntl.h>
  42 #include <time.h>
  43 #include <unistd.h>
  44 #include <string.h>
  45 #include <sys/mman.h>
  46 #include <sys/stat.h>
  47 #include <err.h>
  48
  49 static char *
  50 write_random_file(int fd, size_t sz)
  51 {
  52     char *buf;
  53     int i;
  54
  55     buf = malloc(sz);
  56     if (buf == NULL)
  57         err(1, "malloc %u", (unsigned)sz);
  58
  59     for (i = 0; i < sz; ++i)
  60         buf[i] = rand();
  61
  62     if (write(fd, buf, sz) != sz)
  63         err(1, "write");
  64
  65     return buf;
  66 }
  67
  68 static void
  69 write_null_file(int fd, size_t sz)
  70 {
  71     char *buf;
  72     int i;
  73
  74     buf = malloc(sz);
  75     if (buf == NULL)
  76         err(1, "malloc %u", (unsigned)sz);
  77
  78     for (i = 0; i < sz; ++i)
  79         buf[i] = 0;
  80
  81     if (write(fd, buf, sz) != sz)
  82         err(1, "write");
  83
  84     free(buf);
  85 }
  86
  87 static char *
  88 read_file(int fd, size_t sz)
  89 {
  90     char *buf;
  91     ssize_t ret;
  92
  93     buf = malloc(sz);
  94     if (buf == NULL)
  95         err(1, "malloc %u", (unsigned)sz);
  96     ret = read(fd, buf, sz);
  97     if (ret < 0)
  98         err(1, "read");
  99     else if (ret == 0)
 100         errx(1, "EOF on read");
 101     return buf;
 102 }
 103
 104 #ifndef MAP_FAILED
 105 #define MAP_FAILED ((void *)-1)
 106 #endif
 107
 108 int
 109 main(int argc, char **argv)
 110 {
 111     const char *file = "foo";
 112     const size_t sz = 16384;
 113     char *random_buf;
 114     char *read_buf1;
 115     char *read_buf2;
 116     int fd;
 117
 118
 119     srand(time(NULL));
 120
 121     fd = open(file, O_RDWR | O_CREAT, 0);
 122     if (fd < 0)
 123         err(1, "open %s", file);
 124
 125     if (lseek(fd, 0, SEEK_SET) < 0)
 126         err(1, "lseek");
 127     write_null_file(fd, sz);
 128     if (lseek(fd, 0, SEEK_SET) < 0)
 129         err(1, "lseek");
 130     read_buf1 = read_file(fd, sz);
 131     if (lseek(fd, 0, SEEK_SET) < 0)
 132         err(1, "lseek");
 133     random_buf = write_random_file(fd, sz);
 134     if (lseek(fd, 0, SEEK_SET) < 0)
 135         err(1, "lseek");
 136     read_buf2 = read_file(fd, sz);
 137
 138     close(fd);
 139     unlink(file);
 140     if (memcmp(random_buf, read_buf2, sz) != 0)
 141         return 1;
 142     return 0;
 143 }