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 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.