src/tests/write3.c

   1 /*
   2  * Copyright (c) 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 <sys/types.h>
  39
  40 #include <stdio.h>
  41
  42 #include <sys/stat.h>
  43 #include <fcntl.h>
  44 #include <unistd.h>
  45
  46
  47 #include <err.h>
  48
  49 const char *fn = "foobar";
  50
  51 static void
  52 check_size(const char *fn, size_t sz, int paranoia)
  53 {
  54     struct stat sb;
  55
  56     if (paranoia)
  57         return;
  58
  59     if (stat(fn, &sb) < 0)
  60         err(1, "stat");
  61     if (sb.st_size != sz)
  62         errx(1, "st_size mismatch %d != %d", (int)sb.st_size, (int)sz);
  63 }
  64
  65 static void
  66 check_size_read(int fd, size_t sz)
  67 {
  68     off_t old_off;
  69     size_t sz2;
  70     void *buf;
  71
  72     if ((old_off = lseek(fd, 0, SEEK_CUR)) < 0)
  73         err(1, "lseek");
  74
  75     if (lseek(fd, 0, SEEK_SET) < 0)
  76         err(1, "lseek");
  77     buf = malloc(sz);
  78     if (buf == NULL)
  79         errx(1, "malloc");
  80     if ((sz2 = read(fd, buf, sz)) < 0)
  81         errx(1, "read");
  82     if (sz2 != sz)
  83         errx(1, "end before end: sz2 (%u) != sz (%u)", (unsigned)sz2,
  84              (unsigned)sz);
  85     if ((sz2 = lseek(fd, 0, SEEK_END)) < 0)
  86         errx(1, "lseek");
  87     if (sz2 != sz)
  88         errx(1, "end past end: sz2 (%u) != sz (%u)", (unsigned)sz2,
  89              (unsigned)sz);
  90     free(buf);
  91 }
  92
  93
  94 int
  95 main(int argc, char **argv)
  96 {
  97     int fd;
  98
  99     fd = open(fn, O_RDWR | O_CREAT | O_TRUNC, 0644);
 100     if (fd < 0)
 101         err(1, "open1");
 102     if (write(fd, "kaka", 4) != 4)
 103         errx(1, "write1");
 104     check_size(fn, 4, 1);
 105     if (close(fd) < 0)
 106         err(1, "close1");
 107
 108     check_size(fn, 4, 0);
 109
 110     fd = open(fn, O_RDWR | O_CREAT | O_TRUNC, 644);
 111     if (fd < 0)
 112         err(1, "open2");
 113     check_size(fn, 0, 1);
 114     if (write(fd, "kaka", 4) != 4)
 115         errx(1, "write2");
 116     check_size(fn, 4, 1);
 117     check_size_read(fd, 4);
 118     if (close(fd) < 0)
 119         err(1, "close2");
 120     check_size(fn, 4, 1);
 121
 122     unlink(fn);
 123
 124     return 0;
 125 }