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  * \ingroup functions
  25  */
  26
  27 #include "asterisk.h"
  28
  29 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  30
  31 #include "asterisk/module.h"
  32 #include "asterisk/channel.h"
  33 #include "asterisk/pbx.h"
  34 #include "asterisk/utils.h"
  35 #include "asterisk/app.h"
  36
  37 static int acf_rand_exec(struct ast_channel *chan, const char *cmd,
  38                          char *parse, char *buffer, size_t buflen)
  39 {
  40         int min_int, response_int, max_int;
  41         AST_DECLARE_APP_ARGS(args,
  42                              AST_APP_ARG(min);
  43                              AST_APP_ARG(max);
  44         );
  45
  46         AST_STANDARD_APP_ARGS(args, parse);
  47
  48         if (ast_strlen_zero(args.min) || sscanf(args.min, "%d", &min_int) != 1)
  49                 min_int = 0;
  50
  51         if (ast_strlen_zero(args.max) || sscanf(args.max, "%d", &max_int) != 1)
  52                 max_int = RAND_MAX;
  53
  54         if (max_int < min_int) {
  55                 int tmp = max_int;
  56
  57                 max_int = min_int;
  58                 min_int = tmp;
  59                 ast_debug(1, "max<min\n");
  60         }
  61
  62         response_int = min_int + (ast_random() % (max_int - min_int + 1));
  63         ast_debug(1, "%d was the lucky number in range [%d,%d]\n", response_int, min_int, max_int);
  64         snprintf(buffer, buflen, "%d", response_int);
  65
  66         return 0;
  67 }
  68
  69 static struct ast_custom_function acf_rand = {
  70         .name = "RAND",
  71         .synopsis = "Choose a random number in a range",
  72         .syntax = "RAND([min][,max])",
  73         .desc =
  74                 "Choose a random number between min and max.  Min defaults to 0, if not\n"
  75                 "specified, while max defaults to RAND_MAX (2147483647 on many systems).\n"
  76                 "  Example:  Set(junky=${RAND(1,8)}); \n"
  77                 "  Sets junky to a random number between 1 and 8, inclusive.\n",
  78         .read = acf_rand_exec,
  79 };
  80
  81 static int unload_module(void)
  82 {
  83         ast_custom_function_unregister(&acf_rand);
  84
  85         return 0;
  86 }
  87
  88 static int load_module(void)
  89 {
  90         return ast_custom_function_register(&acf_rand);
  91 }
  92
  93 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Random number dialplan function");