watch(8) [freebsd man page]

WATCH(8)						    BSD 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 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, interac-
	     tive 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 pre-
	     ceded 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), sio(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.

BSD
								 November 24, 2001							       BSD

Check Out this Related Man Page

tty(1)								   User Commands							    tty(1)

NAME

       tty - return user's terminal name

SYNOPSIS

       tty [-l] [-s]

DESCRIPTION

       The  tty utility writes to the standard output the name of the terminal that is open as standard input. The name that is used is equivalent
       to the string that would be returned by the ttyname(3C) function.

OPTIONS

       The following options are supported:

       -l	Prints the synchronous line number to which the user's terminal is connected, if it is on an active synchronous line.

       -s	Inhibits printing of the terminal path name, allowing one to test just the exit status.

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of the following environment variables that affect the execution of  tty: LANG, LC_ALL, LC_CTYPE,   LC_MES-
       SAGES,  and NLSPATH.

EXIT STATUS

       The following exit values are returned:

       0	Standard input is a terminal.

       1	Standard input is not a terminal.

       >1	An error occurred.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |CSI			     |enabled			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       isatty(3C), ttyname(3C), attributes(5), environ(5), standards(5)

DIAGNOSTICS

       not on an active synchronous line

	   The standard input is not a synchronous terminal and -l is specified.

       not a tty

	   The standard input is not a terminal and -s is not specified.

NOTES

       The -s option is useful only if the exit status is wanted. It does not rely on the ability to form a valid path name. Portable applications
       should use test -t.

SunOS 5.10							    1 Feb 1995								    tty(1)

Linux and UNIX Man Pages

watch(8) [freebsd man page]

Check Out this Related Man Page