tests/pine.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 #include <sys/stat.h>
  44
  45 #include <err.h>
  46 #include <roken.h>
  47
  48 RCSID("$Id$");
  49
  50 #define LOCK            "mailbox-name.lock"
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55     int ret;
  56     struct stat sb;
  57     char unique[1024];
  58     int retrycount = 0;
  59
  60     setprogname (argv[0]);
  61
  62     snprintf (unique, sizeof(unique), LOCK ".%d.%d",
  63               getpid(), (int)time(NULL));
  64
  65     ret = umask(077);
  66     if (ret < 0)
  67         err (1, "umask");
  68
  69     ret = open(unique, O_WRONLY|O_CREAT|O_EXCL, 0666);
  70     if (ret < 0)
  71         errx (1, "open");
  72
  73     close (ret);
  74
  75  retry:
  76     retrycount++;
  77     if (retrycount > 10000000)
  78         errx (1, "failed getting the lock");
  79     ret = link(unique, LOCK);
  80     if (ret < 0)
  81         goto retry;
  82
  83     ret = stat(unique, &sb);
  84     if (ret < 0)
  85         errx (1, "stat");
  86
  87     if (sb.st_nlink != 2)
  88         goto retry;
  89
  90     ret = chmod (LOCK, 0666);
  91     if (ret < 0)
  92         errx (1, "chmod");
  93
  94     ret = unlink (LOCK);
  95     if (ret < 0)
  96         err (1, "unlink " LOCK);
  97
  98     ret = unlink (unique);
  99     if (ret < 0)
 100         err (1, "unlink: %s", unique);
 101
 102     return 0;
 103 }