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74 lines
2.0 KiB
Groff
74 lines
2.0 KiB
Groff
.Dd December 10, 1993
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.Dt COMCONTROL 8
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.Os FreeBSD
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.Sh NAME
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.Nm comcontrol
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.Nd "control the bidirectional status of a sio port and waiting time after DTR drop"
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.Sh SYNOPSIS
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.Nm comcontrol
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.Ar sio_special_device
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.Op Cm bidir | Fl bidir
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.Op Cm dtrwait Ar ticks
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.Sh DESCRIPTION
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.Nm Comcontrol
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is used to examine and modify the bidirectional status
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of a specified
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sio communications port
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and its waiting time after DTR drop.
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By default (if
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.Ar sio_special_device
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only specified),
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.Nm comcontrol
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will print the current port state
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(if kernel was built with
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.Cm options COM_BIDIR )
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as either
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.Cm bidir
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to indicate that bidirectional operation is enabled or
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.Fl bidir
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to indicate that it is disabled, string
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.Cm dtrwait
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and current waiting time in ticks
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after DTR drop.
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To modify the status of the port or waiting time, simply
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specify the desired new state
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and/or new waiting time
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on the command line. All users with
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read access to the
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.Ar sio_special_device
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can use
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.Nm comcontrol
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to get the port's status and current waiting time.
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Only root can set a port's status and waiting time.
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By default, each port is initially unidirectional, waiting time is 50 ticks.
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.Pp
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The standard way to use
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.Nm comcontrol
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is to put invocations of it in the
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.Ar /etc/rc.local
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startup script.
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.Sh SEE ALSO
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.Xr sio 4
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.Sh FILES
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.Bl -tag -width Pa
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.It Pa /dev/sio??
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.Sh DIAGNOSTICS
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.Cm TIOCMSBIDIR: Inappropriate ioctl for device.
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.Pp
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This indicates attempt to change port status on
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a non-sio special device file,
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or the kernel has not been built with
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.Cm options COM_BIDIR .
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For more information concerning reconfiguration
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of your kernel see
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.Ar /usr/src/sys/i386/doc/config_options.doc.
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.Sh AUTHOR
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Christopher G. Demetriou
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.Sh BUGS
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It is strongly recommended that you do *not*
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change the bidirectional status of a port while there are programs
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using the port. Read that as: if you do, and it breaks, don't yell
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at me; that's a really weird thing to do.
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.Sh HISTORY
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Originally part of cgd's com package patches, version 0.2.1, to 386BSD 0.1.
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