funcs/func_rand.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 2006, Digium, Inc.
   5  * Copyright (C) 2006, Claude Patry
   6  *
   7  * See http://www.asterisk.org for more information about
   8  * the Asterisk project. Please do not directly contact
   9  * any of the maintainers of this project for assistance;
  10  * the project provides a web site, mailing lists and IRC
  11  * channels for your use.
  12  *
  13  * This program is free software, distributed under the terms of
  14  * the GNU General Public License Version 2. See the LICENSE file
  15  * at the top of the source tree.
  16  */
  17
  18 /*! \file
  19  *
  20  * \brief Generate Random Number
  21  *
  22  * \author Claude Patry <cpatry@gmail.com>
  23  * \author Tilghman Lesher ( http://asterisk.drunkcoder.com/ )
  24  */
  25
  26 #include "asterisk.h"
  27
  28 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  29
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdio.h>
  33 #include <sys/types.h>
  34
  35 #include "asterisk/module.h"
  36 #include "asterisk/channel.h"
  37 #include "asterisk/pbx.h"
  38 #include "asterisk/logger.h"
  39 #include "asterisk/utils.h"
  40 #include "asterisk/app.h"
  41
  42 static int acf_rand_exec(struct ast_channel *chan, char *cmd,
  43                          char *parse, char *buffer, size_t buflen)
  44 {
  45         struct ast_module_user *u;
  46         int min_int, response_int, max_int;
  47         AST_DECLARE_APP_ARGS(args,
  48                              AST_APP_ARG(min);
  49                              AST_APP_ARG(max);
  50         );
  51
  52         u = ast_module_user_add(chan);
  53
  54         AST_STANDARD_APP_ARGS(args, parse);
  55
  56         if (ast_strlen_zero(args.min) || sscanf(args.min, "%d", &min_int) != 1)
  57                 min_int = 0;
  58
  59         if (ast_strlen_zero(args.max) || sscanf(args.max, "%d", &max_int) != 1)
  60                 max_int = RAND_MAX;
  61
  62         if (max_int < min_int) {
  63                 int tmp = max_int;
  64
  65                 max_int = min_int;
  66                 min_int = tmp;
  67                 ast_log(LOG_DEBUG, "max<min\n");
  68         }
  69
  70         response_int = min_int + (ast_random() % (max_int - min_int + 1));
  71         ast_log(LOG_DEBUG, "%d was the lucky number in range [%d,%d]\n",
  72                 response_int, min_int, max_int);
  73         snprintf(buffer, buflen, "%d", response_int);
  74
  75         ast_module_user_remove(u);
  76
  77         return 0;
  78 }
  79
  80 static struct ast_custom_function acf_rand = {
  81         .name = "RAND",
  82         .synopsis = "Choose a random number in a range",
  83         .syntax = "RAND([min][|max])",
  84         .desc =
  85                 "Choose a random number between min and max.  Min defaults to 0, if not\n"
  86                 "specified, while max defaults to RAND_MAX (2147483647 on many systems).\n"
  87                 "  Example:  Set(junky=${RAND(1|8)}); \n"
  88                 "  Sets junky to a random number between 1 and 8, inclusive.\n",
  89         .read = acf_rand_exec,
  90 };
  91
  92 static int unload_module(void)
  93 {
  94         ast_custom_function_unregister(&acf_rand);
  95
  96         return 0;
  97 }
  98
  99 static int load_module(void)
 100 {
 101         return ast_custom_function_register(&acf_rand);
 102 }
 103
 104 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Random number dialplan function");