miscutils/update.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini update implementation for busybox; much pasted from update-2.11
   4  *
   5  *
   6  * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
   7  * Copyright (c) 1996, 1997, 1999 Torsten Poulin.
   8  * Copyright (c) 2000 by Karl M. Hegbloom <karlheg@debian.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  */
  25
  26 #include "internal.h"
  27 #include <sys/param.h>
  28 #include <sys/syslog.h>
  29
  30
  31 #if defined(__GLIBC__)
  32 #include <sys/kdaemon.h>
  33 #else
  34 static _syscall2(int, bdflush, int, func, int, data);
  35 #endif                                                  /* __GLIBC__ */
  36
  37 static unsigned int sync_duration = 30;
  38 static unsigned int flush_duration = 5;
  39 static int use_sync = 0;
  40
  41 extern int update_main(int argc, char **argv)
  42 {
  43         int pid;
  44
  45         argc--;
  46         argv++;
  47         while (argc>0 && **argv == '-') {
  48                 while (*++(*argv)) {
  49                         switch (**argv) {
  50                         case 'S':
  51                                 use_sync = 1;
  52                                 break;
  53                         case 's':
  54                                 if (--argc < 1) usage(update_usage);
  55                                 sync_duration = atoi(*(++argv));
  56                                 break;
  57                         case 'f':
  58                                 if (--argc < 1) usage(update_usage);
  59                                 flush_duration = atoi(*(++argv));
  60                                 break;
  61                         default:
  62                                 usage(update_usage);
  63                         }
  64                 }
  65                 argc--;
  66                 argv++;
  67         }
  68
  69         pid = fork();
  70         if (pid < 0)
  71                 exit(FALSE);
  72         else if (pid == 0) {
  73                 /* Become a proper daemon */
  74                 setsid();
  75                 chdir("/");
  76                 for (pid = 0; pid < OPEN_MAX; pid++) close(pid);
  77
  78                 /*
  79                  * This is no longer necessary since 1.3.5x, but it will harmlessly
  80                  * exit if that is the case.
  81                  */
  82                 argv[0] = "bdflush (update)";
  83                 argv[1] = NULL;
  84                 argv[2] = NULL;
  85                 for (;;) {
  86                         if (use_sync) {
  87                                 sleep(sync_duration);
  88                                 sync();
  89                         } else {
  90                                 sleep(flush_duration);
  91                                 if (bdflush(1, 0) < 0) {
  92                                         openlog("update", LOG_CONS, LOG_DAEMON);
  93                                         syslog(LOG_INFO,
  94                                                    "This kernel does not need update(8). Exiting.");
  95                                         closelog();
  96                                         exit(TRUE);
  97                                 }
  98                         }
  99                 }
 100         }
 101         return( TRUE);
 102 }
 103
 104 /*
 105 Local Variables:
 106 c-file-style: "linux"
 107 c-basic-offset: 4
 108 tab-width: 4
 109 End:
 110 */