src/tests/truncate.c

   1 /*
   2  * Copyright (c) 2000 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 <unistd.h>
  40 #include <fcntl.h>
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43
  44 #include <err.h>
  45
  46 static void
  47 create_and_write(char *name, const char *buf)
  48 {
  49     int fd, ret;
  50     int len = strlen(buf);
  51
  52     fd = open(name, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  53     if (fd < 0)
  54         err(1, "open");
  55     ret = write(fd, buf, len);
  56     if (ret != len)
  57         err(1, "write");
  58     ret = close(fd);
  59     if (ret < 0)
  60         err(1, "close");
  61 }
  62
  63 static void
  64 check_size(char *name, int len)
  65 {
  66     struct stat sb;
  67     int ret;
  68
  69     ret = stat(name, &sb);
  70     if (ret < 0)
  71         err(1, "stat");
  72
  73     if (len != sb.st_size)
  74         errx(1, "len != sb.st_size");
  75 }
  76
  77 int
  78 main(int argc, char **argv)
  79 {
  80     int ret;
  81
  82
  83     create_and_write("foo", "hej\n");
  84
  85     ret = truncate("foo", 0);
  86     if (ret < 0)
  87         err(1, "truncate(0)");
  88
  89     check_size("foo", 0);
  90
  91     ret = unlink("foo");
  92     if (ret < 0)
  93         errx(1, "unlink");
  94
  95     create_and_write("bar", "hej\nhej\n");
  96
  97     ret = truncate("bar", 16);
  98     if (ret < 0)
  99         err(1, "truncate(16)");
 100
 101     check_size("bar", 16);
 102
 103     ret = unlink("bar");
 104     if (ret < 0)
 105         errx(1, "unlink");
 106
 107     return 0;
 108 }