автоматизированный разговорный скрипт с модемом (Automated conversational script with a modem)
SENDING DATA FROM A FILE
If the string to send starts with an at sign (@), the rest of the
string is taken to be the name of a file to read to get the
string to send. If the last character of the data read is a
newline, it is removed. The file can be a named pipe (or fifo)
instead of a regular file. This provides a way for chat to
communicate with another program, for example, a program to
prompt the user and receive a password typed in.
