C.16. ENV()

ENV(variablename)
Reads/sets an environment variable (a variable in the operating system environment - these can be viewed from the shell with echo $variablename). Environment variables are case-sensitive and are almost always written all uppercase.
; read HOME:
exten => 123,1,Set(foo=${ENV(HOME)})

; set HOME:
exten => 123,1,Set(ENV(HOME)=/myAst)

Note

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

[Syntax]
ENV(<envname>)

[Synopsis]
Gets or sets the environment variable specified

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