Wed Aug 15 01:24:21 2007

Asterisk developer's documentation


func_logic.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2006, Digium, Inc.
00005  * Portions Copyright (C) 2005, Anthony Minessale II
00006  *
00007  * See http://www.asterisk.org for more information about
00008  * the Asterisk project. Please do not directly contact
00009  * any of the maintainers of this project for assistance;
00010  * the project provides a web site, mailing lists and IRC
00011  * channels for your use.
00012  *
00013  * This program is free software, distributed under the terms of
00014  * the GNU General Public License Version 2. See the LICENSE file
00015  * at the top of the source tree.
00016  */
00017 
00018 /*! \file
00019  * 
00020  * \brief Conditional logic dialplan functions
00021  * 
00022  * \author Anthony Minessale II
00023  */
00024 
00025 #include "asterisk.h"
00026 
00027 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 44808 $")
00028 
00029 #include <stdio.h>
00030 #include <stdlib.h>
00031 #include <string.h>
00032 #include <sys/types.h>
00033 
00034 #include "asterisk/module.h"
00035 #include "asterisk/channel.h"
00036 #include "asterisk/pbx.h"
00037 #include "asterisk/logger.h"
00038 #include "asterisk/utils.h"
00039 #include "asterisk/app.h"
00040 
00041 static int isnull(struct ast_channel *chan, char *cmd, char *data,
00042         char *buf, size_t len)
00043 {
00044    strcpy(buf, data && *data ? "0" : "1");
00045 
00046    return 0;
00047 }
00048 
00049 static int exists(struct ast_channel *chan, char *cmd, char *data, char *buf,
00050         size_t len)
00051 {
00052    strcpy(buf, data && *data ? "1" : "0");
00053 
00054    return 0;
00055 }
00056 
00057 static int iftime(struct ast_channel *chan, char *cmd, char *data, char *buf,
00058         size_t len)
00059 {
00060    struct ast_timing timing;
00061    char *expr;
00062    char *iftrue;
00063    char *iffalse;
00064 
00065    data = ast_strip_quoted(data, "\"", "\"");
00066    expr = strsep(&data, "?");
00067    iftrue = strsep(&data, ":");
00068    iffalse = data;
00069 
00070    if (ast_strlen_zero(expr) || !(iftrue || iffalse)) {
00071       ast_log(LOG_WARNING,
00072             "Syntax IFTIME(<timespec>?[<true>][:<false>])\n");
00073       return -1;
00074    }
00075 
00076    if (!ast_build_timing(&timing, expr)) {
00077       ast_log(LOG_WARNING, "Invalid Time Spec.\n");
00078       return -1;
00079    }
00080 
00081    if (iftrue)
00082       iftrue = ast_strip_quoted(iftrue, "\"", "\"");
00083    if (iffalse)
00084       iffalse = ast_strip_quoted(iffalse, "\"", "\"");
00085 
00086    ast_copy_string(buf, ast_check_timing(&timing) ? iftrue : iffalse, len);
00087 
00088    return 0;
00089 }
00090 
00091 static int acf_if(struct ast_channel *chan, char *cmd, char *data, char *buf,
00092         size_t len)
00093 {
00094    char *expr;
00095    char *iftrue;
00096    char *iffalse;
00097 
00098    data = ast_strip_quoted(data, "\"", "\"");
00099    expr = strsep(&data, "?");
00100    iftrue = strsep(&data, ":");
00101    iffalse = data;
00102 
00103    if (ast_strlen_zero(expr) || !(iftrue || iffalse)) {
00104       ast_log(LOG_WARNING, "Syntax IF(<expr>?[<true>][:<false>])\n");
00105       return -1;
00106    }
00107 
00108    expr = ast_strip(expr);
00109    if (iftrue)
00110       iftrue = ast_strip_quoted(iftrue, "\"", "\"");
00111    if (iffalse)
00112       iffalse = ast_strip_quoted(iffalse, "\"", "\"");
00113 
00114    ast_copy_string(buf, pbx_checkcondition(expr) ? (S_OR(iftrue, "")) : (S_OR(iffalse, "")), len);
00115 
00116    return 0;
00117 }
00118 
00119 static int set(struct ast_channel *chan, char *cmd, char *data, char *buf,
00120           size_t len)
00121 {
00122    char *varname;
00123    char *val;
00124 
00125    varname = strsep(&data, "=");
00126    val = data;
00127 
00128    if (ast_strlen_zero(varname) || !val) {
00129       ast_log(LOG_WARNING, "Syntax SET(<varname>=[<value>])\n");
00130       return -1;
00131    }
00132 
00133    varname = ast_strip(varname);
00134    val = ast_strip(val);
00135    pbx_builtin_setvar_helper(chan, varname, val);
00136    ast_copy_string(buf, val, len);
00137 
00138    return 0;
00139 }
00140 
00141 static struct ast_custom_function isnull_function = {
00142    .name = "ISNULL",
00143    .synopsis = "NULL Test: Returns 1 if NULL or 0 otherwise",
00144    .syntax = "ISNULL(<data>)",
00145    .read = isnull,
00146 };
00147 
00148 static struct ast_custom_function set_function = {
00149    .name = "SET",
00150    .synopsis = "SET assigns a value to a channel variable",
00151    .syntax = "SET(<varname>=[<value>])",
00152    .read = set,
00153 };
00154 
00155 static struct ast_custom_function exists_function = {
00156    .name = "EXISTS",
00157    .synopsis = "Existence Test: Returns 1 if exists, 0 otherwise",
00158    .syntax = "EXISTS(<data>)",
00159    .read = exists,
00160 };
00161 
00162 static struct ast_custom_function if_function = {
00163    .name = "IF",
00164    .synopsis =
00165       "Conditional: Returns the data following '?' if true else the data following ':'",
00166    .syntax = "IF(<expr>?[<true>][:<false>])",
00167    .read = acf_if,
00168 };
00169 
00170 static struct ast_custom_function if_time_function = {
00171    .name = "IFTIME",
00172    .synopsis =
00173       "Temporal Conditional: Returns the data following '?' if true else the data following ':'",
00174    .syntax = "IFTIME(<timespec>?[<true>][:<false>])",
00175    .read = iftime,
00176 };
00177 
00178 static int unload_module(void)
00179 {
00180    int res = 0;
00181 
00182    res |= ast_custom_function_unregister(&isnull_function);
00183    res |= ast_custom_function_unregister(&set_function);
00184    res |= ast_custom_function_unregister(&exists_function);
00185    res |= ast_custom_function_unregister(&if_function);
00186    res |= ast_custom_function_unregister(&if_time_function);
00187 
00188    return res;
00189 }
00190 
00191 static int load_module(void)
00192 {
00193    int res = 0;
00194 
00195    res |= ast_custom_function_register(&isnull_function);
00196    res |= ast_custom_function_register(&set_function);
00197    res |= ast_custom_function_register(&exists_function);
00198    res |= ast_custom_function_register(&if_function);
00199    res |= ast_custom_function_register(&if_time_function);
00200 
00201    return res;
00202 }
00203 
00204 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Logical dialplan functions");

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