автоматизированный разговорный скрипт с модемом (Automated conversational script with a modem)
Переменные окружения (Environment variables)
Environment variables are available within chat scripts, if the
-E option was specified in the command line. The metacharacter $
is used to introduce the name of the environment variable to
substitute. If the substitution fails, because the requested
environment variable is not set, nothing is replaced for the
variable.
