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WATCH(8)		FreeBSD	System Manager's Manual		      WATCH(8)

NAME
     watch -- snoop on another tty line

SYNOPSIS
     watch [-cinotW] [-f snpdev] [tty]

DESCRIPTION
     The watch utility allows the user to examine all data coming through a
     specified tty using the snp(4) device.  If	the snp(4) device is not
     available,	watch will attempt to load the module (snp).  The watch	util-
     ity writes	to standard output.

     The options are as	follows:

     -c	     Reconnect on close.  If the tty observed by watch is closed, au-
	     tomatically reattach to the same tty.  If this option is not
	     specified,	watch will request a new tty if	running	in interactive
	     mode or exit if running without a controlling tty.

     -f	snpdev
	     If	this option is specified, watch	will use snpdev	as the snp(4)
	     device.  Without this option, watch will attempt to find the next
	     available snp(4) device.

     -i	     Force interactive mode.  Interactive mode is a default if watch
	     is	started	from a tty.  If	output is redirected to	a file,	inter-
	     active mode can still be requested	by specifying this option.

     -n	     Disable the ability to switch the watched tty interactively.
	     This disables both	change requests	made with <control-X> as well
	     as	automatic prompting when the current tty is closed or over-
	     flows.  In	all cases where	a prompt would be displayed, watch
	     will exit.	 The reconnect flags are unaffected by this option.
	     When this flag is used, <control-X> is passed through to the ter-
	     minal.

     -o	     Reconnect on overflow.  The behavior of watch if the observed tty
	     overflows is similar to the behavior if the observed tty is
	     closed.  For more info see	snp(4).

     -t	     Print the date and	time when observation of a given tty is
	     started.

     -W	     Allow write access	to observed tty.

     tty     Tty may be	specified as a tty-style device, such as a pseudo tty
	     device, a virtual console,	or a serial line, etc.	Names may be
	     preceded by /dev/.

OPERATION
     While running in interactive mode,	all user input is discarded except
     for:

     <control-G>
	   Exit	watch.
     <control-W>
	   Clear screen.
     <control-X>
	   Change attached tty,	unless this feature is disabled, in which case
	   control-X is	passed to the terminal as with other control charac-
	   ters.

SEE ALSO
     pty(4), snp(4), kldload(8)

HISTORY
     The watch utility first appeared in FreeBSD 2.1.

AUTHORS
     Ugen J.S. Antsilevich <ugen@NetVision.net.il>

BUGS
     No	terminal emulation is performed.  All user output is reproduced	as-is.

FreeBSD	13.0		       November	24, 2001		  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | OPERATION | SEE ALSO | HISTORY | AUTHORS | BUGS

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