Mon May 14 04:42:58 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  * \ingroup functions
00025  */
00026 
00027 #include "asterisk.h"
00028 
00029 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
00030 
00031 #include <stdio.h>
00032 #include <stdlib.h>
00033 #include <string.h>
00034 #include <sys/types.h>
00035 
00036 #include "asterisk/module.h"
00037 #include "asterisk/channel.h"
00038 #include "asterisk/pbx.h"
00039 #include "asterisk/logger.h"
00040 #include "asterisk/utils.h"
00041 #include "asterisk/app.h"
00042 
00043 static int isnull(struct ast_channel *chan, char *cmd, char *data,
00044         char *buf, size_t len)
00045 {
00046    strcpy(buf, data && *data ? "0" : "1");
00047 
00048    return 0;
00049 }
00050 
00051 static int exists(struct ast_channel *chan, char *cmd, char *data, char *buf,
00052         size_t len)
00053 {
00054    strcpy(buf, data && *data ? "1" : "0");
00055 
00056    return 0;
00057 }
00058 
00059 static int iftime(struct ast_channel *chan, char *cmd, char *data, char *buf,
00060         size_t len)
00061 {
00062    struct ast_timing timing;
00063    char *expr;
00064    char *iftrue;
00065    char *iffalse;
00066 
00067    data = ast_strip_quoted(data, "\"", "\"");
00068    expr = strsep(&data, "?");
00069    iftrue = strsep(&data, ":");
00070    iffalse = data;
00071 
00072    if (ast_strlen_zero(expr) || !(iftrue || iffalse)) {
00073       ast_log(LOG_WARNING,
00074             "Syntax IFTIME(<timespec>?[<true>][:<false>])\n");
00075       return -1;
00076    }
00077 
00078    if (!ast_build_timing(&timing, expr)) {
00079       ast_log(LOG_WARNING, "Invalid Time Spec.\n");
00080       return -1;
00081    }
00082 
00083    if (iftrue)
00084       iftrue = ast_strip_quoted(iftrue, "\"", "\"");
00085    if (iffalse)
00086       iffalse = ast_strip_quoted(iffalse, "\"", "\"");
00087 
00088    ast_copy_string(buf, ast_check_timing(&timing) ? iftrue : iffalse, len);
00089 
00090    return 0;
00091 }
00092 
00093 static int acf_if(struct ast_channel *chan, char *cmd, char *data, char *buf,
00094         size_t len)
00095 {
00096    char *expr;
00097    char *iftrue;
00098    char *iffalse;
00099 
00100    data = ast_strip_quoted(data, "\"", "\"");
00101    expr = strsep(&data, "?");
00102    iftrue = strsep(&data, ":");
00103    iffalse = data;
00104 
00105    if (ast_strlen_zero(expr) || !(iftrue || iffalse)) {
00106       ast_log(LOG_WARNING, "Syntax IF(<expr>?[<true>][:<false>])\n");
00107       return -1;
00108    }
00109 
00110    expr = ast_strip(expr);
00111    if (iftrue)
00112       iftrue = ast_strip_quoted(iftrue, "\"", "\"");
00113    if (iffalse)
00114       iffalse = ast_strip_quoted(iffalse, "\"", "\"");
00115 
00116    ast_copy_string(buf, pbx_checkcondition(expr) ? (S_OR(iftrue, "")) : (S_OR(iffalse, "")), len);
00117 
00118    return 0;
00119 }
00120 
00121 static int set(struct ast_channel *chan, char *cmd, char *data, char *buf,
00122           size_t len)
00123 {
00124    char *varname;
00125    char *val;
00126 
00127    varname = strsep(&data, "=");
00128    val = data;
00129 
00130    if (ast_strlen_zero(varname) || !val) {
00131       ast_log(LOG_WARNING, "Syntax SET(<varname>=[<value>])\n");
00132       return -1;
00133    }
00134 
00135    varname = ast_strip(varname);
00136    val = ast_strip(val);
00137    pbx_builtin_setvar_helper(chan, varname, val);
00138    ast_copy_string(buf, val, len);
00139 
00140    return 0;
00141 }
00142 
00143 static struct ast_custom_function isnull_function = {
00144    .name = "ISNULL",
00145    .synopsis = "NULL Test: Returns 1 if NULL or 0 otherwise",
00146    .syntax = "ISNULL(<data>)",
00147    .read = isnull,
00148 };
00149 
00150 static struct ast_custom_function set_function = {
00151    .name = "SET",
00152    .synopsis = "SET assigns a value to a channel variable",
00153    .syntax = "SET(<varname>=[<value>])",
00154    .read = set,
00155 };
00156 
00157 static struct ast_custom_function exists_function = {
00158    .name = "EXISTS",
00159    .synopsis = "Existence Test: Returns 1 if exists, 0 otherwise",
00160    .syntax = "EXISTS(<data>)",
00161    .read = exists,
00162 };
00163 
00164 static struct ast_custom_function if_function = {
00165    .name = "IF",
00166    .synopsis =
00167       "Conditional: Returns the data following '?' if true else the data following ':'",
00168    .syntax = "IF(<expr>?[<true>][:<false>])",
00169    .read = acf_if,
00170 };
00171 
00172 static struct ast_custom_function if_time_function = {
00173    .name = "IFTIME",
00174    .synopsis =
00175       "Temporal Conditional: Returns the data following '?' if true else the data following ':'",
00176    .syntax = "IFTIME(<timespec>?[<true>][:<false>])",
00177    .read = iftime,
00178 };
00179 
00180 static int unload_module(void)
00181 {
00182    int res = 0;
00183 
00184    res |= ast_custom_function_unregister(&isnull_function);
00185    res |= ast_custom_function_unregister(&set_function);
00186    res |= ast_custom_function_unregister(&exists_function);
00187    res |= ast_custom_function_unregister(&if_function);
00188    res |= ast_custom_function_unregister(&if_time_function);
00189 
00190    return res;
00191 }
00192 
00193 static int load_module(void)
00194 {
00195    int res = 0;
00196 
00197    res |= ast_custom_function_register(&isnull_function);
00198    res |= ast_custom_function_register(&set_function);
00199    res |= ast_custom_function_register(&exists_function);
00200    res |= ast_custom_function_register(&if_function);
00201    res |= ast_custom_function_register(&if_time_function);
00202 
00203    return res;
00204 }
00205 
00206 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Logical dialplan functions");

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