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 #include <fcntl.h>
  25 #include <log.h>
  26
  27 pid_t pid_output_lock(const char *);
  28
  29 pid_t
  30 pid_output (const char *path)
  31 {
  32 #ifndef HAVE_FCNTL
  33   FILE *fp;
  34   pid_t pid;
  35   mask_t oldumask;
  36
  37   pid = getpid();
  38
  39   oldumask = umask(0777 & ~LOGFILE_MASK);
  40   fp = fopen (path, "w");
  41   if (fp != NULL)
  42     {
  43       fprintf (fp, "%d\n", (int) pid);
  44       fclose (fp);
  45       umask(oldumask);
  46       return -1;
  47     }
  48   umask(oldumask);
  49   return pid;
  50 #else
  51   return pid_output_lock(path);
  52 #endif /* HAVE_FCNTL */
  53 }
  54
  55 #ifdef HAVE_FCNTL
  56 pid_t
  57 pid_output_lock (const char *path)
  58 {
  59   int tmp;
  60   int fd;
  61   pid_t pid;
  62   char buf[16];
  63   struct flock lock;
  64   mode_t oldumask;
  65
  66   pid = getpid ();
  67
  68   oldumask = umask(0777 & ~LOGFILE_MASK);
  69   zlog_err( "old umask %d %d", oldumask, 0777 & ~LOGFILE_MASK);
  70   fd = open (path, O_RDWR | O_CREAT, LOGFILE_MASK);
  71       if (fd < 0)
  72         {
  73         zlog_err( "Can't creat pid lock file %s (%s), exit",
  74                  path, strerror(errno));
  75       umask(oldumask);
  76       exit (-1);
  77     }
  78   else
  79     {
  80       umask(oldumask);
  81       memset (&lock, 0, sizeof(lock));
  82
  83       lock.l_type = F_WRLCK;
  84       lock.l_whence = SEEK_END;
  85
  86       if (fcntl(fd, F_SETLK, &lock) < 0)
  87         {
  88           zlog_err("Could not lock pid_file %s, exit", path);
  89           exit (-1);
  90         }
  91
  92       sprintf (buf, "%d\n", (int) pid);
  93       tmp = write (fd, buf, strlen (buf));
  94     }
  95   return pid;
  96 }
  97 #endif /* HAVE_FCNTL */