home | help
WATCH(8)		     System Manager's Manual			WATCH(8)

NAME
     watch -- snoop on another tty line

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

DESCRIPTION
     Watch  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).	Watch writes to standard output.

     The options are as follows:

     -c      Reconnect on close.  If the tty observed by watch is closed,  auto-
	     matically reattach to the same tty.  If this option is  not  speci-
	     fied,  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, interactive
	     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  au-
	     tomatic  prompting when the current tty is closed or overflows.  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 terminal.

     -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 an 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 characters.

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

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

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

HISTORY
     Watch first appeared in FreeBSD 2.1.

FreeBSD 4.7			November 24, 2001			WATCH(8)

home | help