1.\" 2.\" @(#)watch.8 1.1 (FreeBSD) 2/17/95 3.\" 4.Dd February 17, 1995 5.Dt WATCH 8 6.Os 7.Sh NAME 8.Nm watch 9.Nd snoop on another tty line 10.Sh SYNOPSIS 11.Nm watch 12.Op Fl ciotnW 13.Ar tty 14.\" watch [-ciotnW] [<tty name>] 15.Sh DESCRIPTION 16.Nm Watch 17allows the superuser to examine all data coming through a specified tty. 18.Nm Watch 19writes to standard output. 20.Pp 21The options are as follows: 22.Bl -tag -width "-l nul " 23.It Fl c 24Reconnect on close. If the tty observed by 25.Nm watch 26is closed, automatically reattach to the same tty. 27If this option is not specified, 28.Nm watch 29will request a new tty if running in interactive mode or exit if running 30without a controlling tty. 31.It Fl i 32Force interactive mode. 33Interactive mode is a default if 34.Nm watch 35is started from a tty. 36If output is redirected to a file, interactive mode can still be requested 37by specifying this option. 38.It Fl o 39Reconnect on overflow. 40The behavior of 41.Nm watch 42if the observed tty overflows is similar to the behavior if the observed tty 43is closed. 44For more info see 45.Xr snp 4 . 46.It Fl t 47Print the date and time when observation of a given tty is started. 48.It Fl n 49Disable the ability to switch the watched tty interactively. This disables 50both change requests made with <control-X> as well as automatic prompting 51when the current tty is closed or overflows. In all cases where a prompt 52would be displayed, watch will exit. The reconnect flags are unaffected by 53this option. 54.It Fl W 55Allow write access to observed tty. 56.It Ar tty 57Tty may be specified as an tty-style device, such as a pseudo tty device, 58a virtual console, or a serial line, etc. 59Names may be preceded by "/dev/". 60.Sh OPERATION 61While running in interactive mode, all user input is discarded except for: 62.Pp 63.Bl -tag -width "XXXX" -compact 64.It Sy "<control-G>" 65Exit 66.Nm watch . 67.It Sy "<control-W>" 68Clear screen. 69.It Sy "<control-X>" 70Change attached tty. 71.Sh RESTRICTIONS 72Only the superuser can run 73.Nm watch . 74.Sh SEE ALSO 75.Xr pty 4 , 76.Xr sio 4 , 77.Xr snp 4 78.Sh BUGS 79No terminal emulation is performed. 80All user output is reproduced as-is. 81.Sh AUTHOR 82Ugen J.S. Antsilevich <ugen@NetVision.net.il> 83.Sh HISTORY 84.Nm Watch 85first appeared in 86.Fx 2.1 . 87