Asterisk之Dialplan编程一般规则
1. 变量设置
使用 Set() 来创建和修改变量：
exten => 1002,1,Set(Favoriteanimal = "Tiger") exten => 1002,n,Set(Favoritenumber = 23)
使用 ${VARIABLENAME} 来读取和打印变量值. 可以在CLI界面打印变量名，通过NoOp（）函数。 (verbosity level >=3 ):
exten => 1003,1,NoOp(${Favoriteanimal})
exten => 1003,n,NoOp(${Favoritenumber})
2.几种变量类型
2.1全局变量，在Dialplan的所有条目中均有效，其设置为：<span style="font-family:Courier New;">Set(<variable>=<content>,g)</span>
<span style="font-family:Courier New;"> exten => 1004,1,Set(READABLEANYWHERE = 23,g)
exten => 1004,n,NoOp(${READABLEANYWHERE})</span>
<span style="font-family:Courier New;"> 2.2通道(channel)变量,只在当前通道中有效，<span style="font-family:Verdana;">其设置为：</span><span style="font-family:Courier New;">Set(<variable>=<content>)</span></span>
<span style="font-family:Courier New;"> e</span><span style="font-family:Courier New;">xten => 1005,1,Set(READABLEHEREONLY= 42)
exten => 1005,n,NoOp(${READABLEHEREONLY})</span>
<span style="font-family:Courier New;"> 2.3系统变量，是指Asterisk预先定义的变量，可以在Dialplan中直接使用，其中的EXTEN表示当前被叫号码</span>
<span style="font-family:Courier New;"> exten => 1006,1,NoOp(Dialed number: ${EXTEN})</span>
<span style="font-family:Courier New;"> 对于如下的语句：</span>
<span style="font-family:Courier New;"> exten => 100,1,Dial(SIP/100) exten => 101,1,Dial(SIP/101) exten => 102,1,Dial(SIP/102) exten => 103,1,Dial(SIP/103) exten => 104,1,Dial(SIP/104) exten => 105,1,Dial(SIP/105) exten => 106,1,Dial(SIP/106) exten => 107,1,Dial(SIP/107) exten => 108,1,Dial(SIP/108) exten => 109,1,Dial(SIP/109) 可以用变量一句话就可以搞定了：</span>
<span style="font-family:Courier New;"> exten => _10X,1,Dial(SIP/${EXTEN})</span>
<span style="font-family:Courier New;">对于字符串变量，定义时最好用双引号括起来：</span>
<span style="font-family:Courier New;"> exten => 1234,1,Set(FRUITTYPES="Apple, Pear, etc.")</span>
<span style="font-family:Courier New;">保留的字符：[ ] $ " /</span>
<span style="font-family:Courier New;"> 如果要使用保留字符的时候，使用/前置，如：</span>
<span style="font-family:Courier New;"> exten => 1234,1,Set(AMOUNT="/$10.00")</span>
<span style="font-family:Courier New;">在extensions.conf中定义全局变量</span>
<span style="font-family:Courier New;"> 全局变量的定义必须放在[globals]中，[globals]放在[general]后，如下例所示：</span>
<span style="font-family:Courier New;"> [general]
[globals]
RINGTIME=90
[from-intern]
exten => _XXX,1,Dial(SIP/${EXTEN},${RINGTIME})
exten => _XXX,n,VoiceMail(${EXTEN})
</span>
<span style="font-family:Courier New;">Set（）函数的格式：Set(<variable1>=<value1>[,<variable2>=<value2>][,<option>]) </span>
<span style="font-family:Courier New;"> ; Set a global variable:
exten => 10,1,Set(RINGTIME=90,g)
; Set a local channel variable:
exten => 10,2,Set(FAVORITEFRUIT="Apple")
; Set two channel variables at once:
exten => 10,3,Set(VAR1=10,VAR2=23)
; Print variables to the CLI
exten => 10,4,NoOp(RINGTIME = ${RINGTIME})
exten => 10,5,NoOp(FAVORITEFRUIT = ${FAVORITEFRUIT})
exten => 10,6,NoOp(VAR1 = ${VAR1})
exten => 10,7,NoOp(VAR2 = ${VAR2})</span>
<span style="font-family:Courier New;">系统定义的一些变量：</span>
<span style="font-family:Courier New;"> </span><dt><span class="term"><code class="code">${ANSWEREDTIME}</code> ：通话时长（以秒为单位）</span></dt>
${BLINDTRANSFER} ：盲转的通道名称（The name of the channel on the other side of a blind transfer.）
<dt><span class="term"><code class="code">${CHANNEL}</code> ：当前通道名称</span></dt><dt>
</dt><dt><span class="term"><code class="code">${CONTEXT}</code> ：当前的上下文</span></dt>
${EPOCH} ：当前的Unix时间（从Unix“epoch"运行开始的总秒数，1970，1，1,0点）
<dt><span class="term"><code class="code">${EXTEN}</code> ：当前的被叫号码</span></dt><dd><p> </p></dd><dt><span class="term"><code class="code">${ENV(VARIABLENAME)}</code> ：系统环境变量VARIABLENAME的值</span></dt>
${HANGUPCAUSE} ：拆线的原因
${INVALID_EXTEN} ：Used in the i extension and contains the dialed extension.
<dt><span class="term"><code class="code">${PRIORITY}</code> ：当前分机的优先值(</span>Current priority in the current extension.)</dt><dt>
</dt><dt><span class="term"><code class="code">${TRANSFER_CONTEXT}</code> ：被转移的呼叫的上下文(</span>Context of a transferred call.)</dt><dt>
</dt><dt><span class="term"><code class="code">${UNIQUEID}</code> :当前连接的唯一ID值(</span>The unique ID for the current connection.)</dt><dt>
</dt><dt><span class="term"><code class="code">${SYSTEMNAME}</code> ：定义在<span style="font-family:Courier New;">/etc/asterisk/asterisk.conf中的systemname值</span></span></dt>
- 字符串的操作：${
VARIABLENAME[:start[:length]]}
<dd>例子1：如果用户拨9出局引示号，然后拨被叫号码，9不应该发出局。</dd><dd>exten => _0X.,1,Set(OUTGOINGNUMBER=${EXTEN:1}) //此时OUTGOINGNUMBER=实际的被叫号码</dd><dd>例子2：如果只需被叫号码的后7位的话，那么应该如此：</dd><dd>exten => _0X.,1,Set(LOCALNUMBER=${EXTEN:-7})</dd><dd>例子3：截取被叫号码从第2位开始，3位号码长度：</dd><dd>exten => _0X.,1,Set(AREACODE=${EXTEN:2:3})</dd>
3. Label 和 Goto（）语句
<p>在一个条目中的跳转:</p><pre name="code" class="programlisting"> exten => 1007,1,Answer() exten => 1007,n(Start),Wait(1) exten => 1007,n,Playback(hello-world) exten => 1007,n,Goto(Start)
在两个条目中的跳转:
exten => 1008,1,Answer() exten => 1008,n,Goto(1009,Ping) exten => 1009,1(Ping),Playback(hello-world) exten => 1009,n,Wait(2) exten => 1009,n,Goto(1010,Pong) exten => 1010,1(Pong),Playback(tt-weasels) exten => 1010,n,Wait(2) exten => 1010,n,Goto(1009,Ping)
在 contexts 之间跳转:
[hq] exten => 1011,1,Answer() exten => 1011,n,Playback(hello-world) exten => 1011,n,Goto(sales,1012,1) [sales] exten => 1012,1,Playback(hello-world) exten => 1012,n,Hangup()
4. While（）循环
exten => 1013,1,Answer()
exten => 1013,n,Set(i=1)
exten => 1013,n,While($[${i} < 10])
exten => 1013,n,SayNumber(${i})
exten => 1013,n,Wait(1)
exten => 1013,n,Set(i=$[${i} + 1])
exten => 1013,n,EndWhile()
exten => 1013,n,Hangup()5. GotoIf()条件判断
exten => 1014,1,Answer()
exten => 1014,n,Set(Favoritestation = 0815)
exten => 1014,n,NoOp(Check to see if ${Favoritestation} is calling.)
exten => 1014,n,GotoIf($[${CALLERID(num)} = ${Favoritestation}]?yes,no)
exten => 1014,n(yes),Playback(hello-world)
exten => 1014,n,Hangup()
exten => 1014,n(no),Playback(tt-monkeys)
exten => 1014,n,Hangup()6. Gosub（）子程序
exten => 1015,1,Gosub(cid-set) // 1 <------------
exten => 1015,n,Dial(SIP/${EXTEN}) //4 <-----------
exten => 1015,n(cid-set),Set(CALLERID(all)=Apfelmus GmbH <012345678>) //2 <------
exten => 1015,n,Return() //3 <---------