C.20. FILTER()

FILTER(allowedCharacters,string)
(beginning Asterisk 1.4)
Filters string so that only the allowed characters are returned.
; allow only 0123456789 from ${cdrnum}:
exten => 123,1,Set(foo=${FILTER(0123456789,${cdrnum})})

Note

Internal help for this application in Asterisk 1.4:
  -= Info about function 'FILTER' =- 

[Syntax]
FILTER(<allowed-chars>|<string>)

[Synopsis]
Filter the string to include only the allowed characters

[Description]
Not available
diff output to internal help in Asterisk 1.2:
-- not available in Version 1.2 --