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

NAME

watchsnoop 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 utility writes to standard output.

The options are as follows:

-c
Reconnect on close. If the tty observed by watch is closed, automatically 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, 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 automatic 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 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 characters.

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.
November 24, 2001 FreeBSD