release/src/router/zebra/lib/pid_output.c

   1 /*
   2  * Process id output.
   3  * Copyright (C) 1998, 1999 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #include <zebra.h>
  24
  25 pid_t
  26 pid_output (char *path)
  27 {
  28   FILE *fp;
  29   pid_t pid;
  30
  31   pid = getpid();
  32
  33   fp = fopen (path, "w");
  34   if (fp != NULL)
  35     {
  36       fprintf (fp, "%d\n", (int) pid);
  37       fclose (fp);
  38       return -1;
  39     }
  40   return pid;
  41 }
  42
  43 pid_t
  44 pid_output_lock (char *path)
  45 {
  46   int tmp;
  47   int fd;
  48   pid_t pid;
  49   char buf[16], *p;
  50
  51   pid = getpid ();
  52
  53   fd = open (path, O_RDWR | O_CREAT | O_EXCL, 0644);
  54   if (fd < 0)
  55     {
  56       fd = open (path, O_RDONLY);
  57       if (fd < 0)
  58         fprintf (stderr, "Can't creat pid lock file, exit\n");
  59       else
  60         {
  61           read (fd, buf, sizeof (buf));
  62           if ((p = index (buf, '\n')) != NULL)
  63             *p = 0;
  64           fprintf (stderr, "Another process(%s) running, exit\n", buf);
  65         }
  66       exit (-1);
  67     }
  68   else
  69     {
  70       sprintf (buf, "%d\n", (int) pid);
  71       tmp = write (fd, buf, strlen (buf));
  72       close (fd);
  73     }
  74
  75   return pid;
  76 }
  77