AT commands as input are sent to modem and responses given as outputhttp://atinout.sourceforge.net
This program will read a file (or stdin) containing a list of AT
commands. Each command will be send to the modem, and all the response
for the command will be output to file (or stdout).
Example, to hang up an ongoing call:
$ echo ATH | atinout - /dev/ttyACM0 -