TTYSOFTCAR(8) System Manager's Manual TTYSOFTCAR(8)
ttysoftcar - enable/disable carrier detect
ttysoftcar [ -y|-n ] tty...
For each tty specified ttysoftcar changes the carrier detect flag using
the TIOCSSOFTCAR ioctl() request (see tty(4)). If the -a option is
specified, ttysoftcar sets all tty's in the /etc/ttytab file to the
carrier detection mode specified by their status field. If this field
is set to local, software carrier detection is turned on. If this
field is set to anything other than local, as is usually the case for
modems, software carrier detection is turned off. ttysoftcar ignores
devices in the /etc/ttytab file which do not exist.
If no options are specified, ttysoftcar returns the current status for
tty. This status is reported as y or n.
-a Reset ttys to appropriate values based on the status field of
the /etc/ttytab file.
-y Turn on software carrier detect.
-n Turn off software carrier detect. Use hardware carrier detect.
termio(4), zs(4S), ttytab(5)
21 July 1989 TTYSOFTCAR(8)