Command Section
COMCONTROL(8)           FreeBSD System Manager's Manual          COMCONTROL(8)

     comcontrol - control a special tty device

     comcontrol special_device [dtrwait number] [drainwait number]

     The comcontrol utility is used to examine and modify some of the special
     characteristics of the specified tty device.  If no arguments other than
     the device (or "-" for stdin) are specified, it prints the settings of
     all controllable characteristics.  This usage requires only read access
     on the device.  Only the superuser can change the settings.

     The following options are available:

     dtrwait number
             Set the time to wait after dropping DTR to the given number.  The
             units are hundredths of a second.  The default is 300 hundredths,
             i.e., 3 seconds.  This option needed mainly to set proper recover
             time after modem reset.

     drainwait number
             Set the time to wait for output drain to the given number.  The
             units are seconds.  The default is 5 minutes, 0 means waiting
             forever.  This option needed mainly to specify upper limit of
             minutes to prevent modem hanging.

     The standard way to use comcontrol is to put invocations of it in the
     /etc/rc.d/serial startup script.

     /dev/ttyd?  dialin devices, hardwired terminals
     /dev/cuau?  dialout devices

     stty(1), sio(4)

     Originally part of cgd's com package patches, version 0.2.1, to
     386BSD-0.1.  Once controlled bidirectional capabilities.  Little is left
     to control now that these capabilities are standard.

     Christopher G. Demetriou

FreeBSD 11.1-RELEASE-p4          May 15, 1994          FreeBSD 11.1-RELEASE-p4
Command Section