dabbad/dabbad.c

   1 /**
   2  * \file dabbad.c
   3  * \author written by Emmanuel Roullit emmanuel.roullit@gmail.com (c) 2012
   4  * \date 2012
   5  */
   6
   7 /* __LICENSE_HEADER_BEGIN__ */
   8
   9 /*
  10  * Copyright (C) 2012   Emmanuel Roullit <emmanuel.roullit@gmail.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
  25  *
  26  */
  27
  28 /* __LICENSE_HEADER_END__ */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <errno.h>
  33 #include <unistd.h>
  34 #include <assert.h>
  35 #include <getopt.h>
  36 #include <sys/types.h>
  37 #include <sys/stat.h>
  38 #include <fcntl.h>
  39
  40 #include <dabbad/ipc.h>
  41 #include <dabbad/help.h>
  42
  43 enum dabbad_opts {
  44         OPT_DAEMONIZE,
  45         OPT_HELP
  46 };
  47
  48 /**
  49  * \brief Dabbad options getter
  50  * \return Dabbad option data structure
  51  */
  52
  53 const struct option *dabbad_options_get(void)
  54 {
  55         static const struct option dabbad_long_options[] = {
  56                 {"daemonize", no_argument, NULL, OPT_DAEMONIZE},
  57                 {"help", no_argument, NULL, OPT_HELP},
  58                 {NULL, 0, NULL, 0}
  59         };
  60
  61         return (dabbad_long_options);
  62 }
  63
  64 /**
  65  * \internal
  66  * \brief Create dabbad pidfile
  67  * \return 0 on success, else on failure.
  68  *
  69  * This function creates start time a file containing dabbad process id.
  70  */
  71
  72 static inline int dabbad_pidfile_create(void)
  73 {
  74         int rc = EIO;
  75         int pidfd = -1;
  76         char pidstr[8] = { 0 };
  77         ssize_t pidstrlen = 0;
  78
  79         pidfd = creat(DABBAD_PID_FILE, 0600);
  80
  81         if (pidfd < 0)
  82                 return errno;
  83
  84         pidstrlen = snprintf(pidstr, sizeof(pidstr), "%i\n", getpid());
  85
  86         if (write(pidfd, pidstr, pidstrlen) != pidstrlen) {
  87                 rc = EIO;
  88         }
  89
  90         close(pidfd);
  91         return rc;
  92 }
  93
  94 /**
  95  * \brief Dabbad entry point
  96  * \param[in]       argc                Argument counter
  97  * \param[in]       argv                Argument vector
  98  * \return 0 on success, else on failure
  99  *
 100  * This function is dabbad entry point.
 101  * It parses given arguments, configure the daemon accordingly and start
 102  * IPC message polling.
 103  */
 104
 105 int main(int argc, char **argv)
 106 {
 107         int opt, opt_idx;
 108         int daemonize = 0;
 109
 110         assert(argc);
 111         assert(argv);
 112
 113         while ((opt =
 114                 getopt_long_only(argc, argv, "", dabbad_options_get(),
 115                                  &opt_idx)) != EOF) {
 116                 switch (opt) {
 117                 case OPT_DAEMONIZE:
 118                         daemonize = 1;
 119                         break;
 120                 case OPT_HELP:
 121                 default:
 122                         show_usage(dabbad_options_get());
 123                         return EXIT_FAILURE;
 124                         break;
 125
 126                 }
 127         }
 128
 129         if (daemonize) {
 130                 if (daemon(-1, 0)) {
 131                         perror("Could not daemonize process");
 132                         return errno;
 133                 }
 134         }
 135
 136         assert(dabbad_pidfile_create());
 137         dabbad_ipc_msg_init();
 138
 139         return dabbad_ipc_msg_poll();
 140 }