sys-utils/ipcmk.c

   1 /*
   2  *  ipcmk.c - used to create ad-hoc IPC segments
   3  *
   4  *  Copyright (C) 2008 Hayden A. James (hayden.james@gmail.com)
   5  *  Copyright (C) 2008 Karel Zak <kzak@redhat.com>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <err.h>
  27 #include <time.h>
  28
  29 #include <unistd.h>
  30 #include <sys/types.h>
  31 #include <sys/ipc.h>
  32 #include <sys/shm.h>
  33 #include <sys/sem.h>
  34 #include <sys/msg.h>
  35
  36 static const char *progname;
  37
  38 key_t createKey(void)
  39 {
  40         srandom( time( NULL ) );
  41         return random();
  42 }
  43
  44 int createShm(size_t size, int permission)
  45 {
  46         int result = -1;
  47         int shmid;
  48         key_t key = createKey();
  49
  50         if (-1 != (shmid = shmget(key, size, permission | IPC_CREAT)))
  51                 result = shmid;
  52
  53         return result;
  54 }
  55
  56 int createMsg(int permission)
  57 {
  58         int result = -1;
  59         int msgid;
  60         key_t key = createKey();
  61
  62         if (-1 != (msgid = msgget(key, permission | IPC_CREAT)))
  63                 result = msgid;
  64
  65         return result;
  66 }
  67
  68 int createSem(int nsems, int permission)
  69 {
  70         int result = -1;
  71         int semid;
  72         key_t key = createKey();
  73
  74         if (-1 != (semid = semget(key, nsems, permission | IPC_CREAT)))
  75                 result = semid;
  76
  77         return result;
  78 }
  79
  80 void usage(int rc)
  81 {
  82         printf("\nUsage: %s [options]\n\n", progname);
  83         printf(
  84         "  -M <size>     create shared memory segment of size <size>\n"
  85         "  -S <nsems>    create semaphore array with <nsems> elements\n"
  86         "  -Q            create message queue\n"
  87         "  -p <mode>     permission for the resource (default is 0644)\n");
  88         printf("\nFor more information see ipcmk(1).\n\n");
  89
  90         exit(rc);
  91 }
  92
  93 int main(int argc, char **argv)
  94 {
  95         int permission = 0644;
  96         int opt;
  97         size_t size = 0;
  98         int nsems = 0;
  99         int doShm = 0, doMsg = 0, doSem = 0;
 100
 101         progname = program_invocation_short_name;
 102         if (!progname)
 103                 progname = "ipcmk";
 104
 105         while((opt = getopt(argc, argv, "hM:QS:p:")) != -1) {
 106                 switch(opt) {
 107                 case 'M':
 108                         size = atoi(optarg);
 109                         doShm = 1;
 110                         break;
 111                 case 'Q':
 112                         doMsg = 1;
 113                         break;
 114                 case 'S':
 115                         nsems = atoi(optarg);
 116                         doSem = 1;
 117                         break;
 118                 case 'p':
 119                         permission = strtoul(optarg, NULL, 8);
 120                         break;
 121                 case 'h':
 122                         usage(EXIT_SUCCESS);
 123                         break;
 124                 default:
 125                         doShm = doMsg = doSem = 0;
 126                         break;
 127                 }
 128         }
 129
 130         if(!doShm && !doMsg && !doSem)
 131                 usage(EXIT_FAILURE);
 132
 133         if (doShm) {
 134                 int shmid;
 135                 if (-1 == (shmid = createShm(size, permission)))
 136                         err(EXIT_FAILURE, "create share memory failed");
 137                 else
 138                         printf("Shared memory id: %d\n", shmid);
 139         }
 140
 141         if (doMsg) {
 142                 int msgid;
 143                 if (-1 == (msgid = createMsg(permission)))
 144                         err(EXIT_FAILURE, "create message queue failed");
 145                 else
 146                         printf("Message queue id: %d\n", msgid);
 147         }
 148
 149         if (doSem) {
 150                 int semid;
 151                 if (-1 == (semid = createSem(nsems, permission)))
 152                         err(EXIT_FAILURE, "create semaphore failed");
 153                 else
 154                         printf("Semaphore id: %d\n", semid);
 155         }
 156
 157         return EXIT_SUCCESS;
 158 }