A very simple command for use in scripts for checking the state of the internal
serial port's CD line.  A local variable "Carrier" is set to either "Yes" or
"No" depending on the existence of a carrier signal.

Read the header of the included E source code for an example of usage.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]                  480     676  71.0% -lh5- 9c4b Jul 15  1995 carrier
[generic]                  442     820  53.9% -lh5- 89c9 Jul 15  1995 Carrier.e
[generic]                   56      63  88.9% -lh5- ca96 Jun 16  1996 readme.first
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         3 files     978    1559  62.7%            Jun 16  1996