EVAL()
Prev  Appendix C. Functions in the dialplan  Next

EVAL() 

EVAL(variable)

Evaluates a variable twice. An example is useful: If the variable ${VAR} contains a string "${VAR2}", that is what is returned when ${VAR} is called. If Eval() is used, the nested variable is also evaluated, and the contents of ${VAR2} are also returned.

; If VAR contains the string "${VAR2}" and VAR2 contains the string "Hel
lo World":
exten => 123,1,Set(foo=${EVAL(${VAR})})
; now foo is "Hello World"
[Note]

Internal help for this application in Asterisk 1.4:  

  -= Info about function 'EVAL' =- 

[Syntax]
EVAL(<variable>)

[Synopsis]
Evaluate stored variables.

[Description]
Using EVAL basically causes a string to be evaluated twice.
When a variable or expression is in the dialplan, it will be
evaluated at runtime. However, if the result of the evaluation
is in fact a variable or expression, using EVAL will have it
evaluated a second time. For example, if the variable ${MYVAR}
contains "${OTHERVAR}", then the result of putting ${EVAL(${MYVAR})}
in the dialplan will be the contents of the variable, OTHERVAR.
Normally, by just putting ${MYVAR} in the dialplan, you would be
left with "${OTHERVAR}".

diff output to internal help in Asterisk 1.2:  

- none -
Prev  Up  Next
ENV()  Home | Inhaltsverzeichnis  EXISTS()