C.18. EXISTS()

EXISTS(variable)
Checks to see if a variable is defined. Returns 1 or 0.
exten => 123,1,Set(Var1=test)
exten => 123,n,Set(Var2=)
exten => 123,n,Set(foo=${EXISTS(${Var1})})   ; foo is 1
exten => 123,n,Set(foo=${EXISTS(${Var2})})   ; foo is 0

Note

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

[Syntax]
EXISTS(<data>)

[Synopsis]
Existence Test: Returns 1 if exists, 0 otherwise

[Description]
Not available
diff output to internal help in Asterisk 1.2:
- none -