How to manipulate/change incoming CallerID in Asterisk dialplan?

Question

I want if number is coming from 91 and is greater than 10 digit so need to remove 91 from the incoming number or else go as it is...

Answer 1

In Asterisk above 1.6

exten => 1234,1,NoOp(Incoming call from # ${CALLERID(num)})

;assign the area code (2 first digits) to variable Digit

exten => 1234,n,Set(Digit=${CALLERID(num):0:2})

 

;Returns integer length of the string.

exten => 1234,n,Set(Number=${LEN(${CALLERID(num)})})

 

;Go to label(True) if condition is true or to next step (or label2(False) if defined) if condition is false

exten => 1234,n,GotoIf($["${Digit}"=="91" && "${Number}">"10"]?True:False)

 

;Removes 91 from the caller number if above condition is true

exten => 1234,n(True),Set(ani=${CALLERID(num):2:12})

exten => 1234,n,Goto(cb,1,1)

 

;else

exten => 1234,n(False),Set(ani=${CALLERID(num)})

exten => 1234,n,Goto(cb,1,1)