freebsd-dev/share/man/man4/snp.4

.\"
.\" $FreeBSD$
.\"
.Dd February 24, 1995
.Dt SNP 4
.Os FreeBSD
.Sh NAME
.Nm snp
.Nd tty snoop interface
.Sh SYNOPSIS
.Fd #include <sys/snoop.h>
.Ft int
.Fn ioctl fd SNPSTTY &dev
.Ft int
.Fn ioctl fd SNPGTTY &dev
.Ft int
.Fn ioctl fd FIONREAD &result
.Sh DESCRIPTION
/dev/snp? are snoop devices which allow user to attach to any tty
and watch activities on it.

To associate a given
.Nm snp
device with a tty to be observed,  open the
.Nm snp
device and then use the SNPSTTY ioctl.
The argument passed to the IOCTL is the address of a variable of type
dev_t.
By setting the value of the variable pointed to -1, the user may detach
the snp device from a tty.
.Pp
The SNPGTTY ioctl returns information about the current tty attached to
the open
.Nm snp
device.
.Pp
The FIONREAD ioctl returns a positive value equal to the number of characters
in a read buffer.
Special values defined are:
.Bl -tag -width SNP_TTYCLOSE
.It Dv SNP_OFLOW
device overflow occured, device detached.
.It Dv SNP_TTYCLOSE
tty not attached.
.It Dv SNP_DETACH
.Nm snp
device has been detached by user or tty device has been closed
and detached.
.Sh SEE ALSO
.Xr pty 4 ,
.Xr sio 4 ,
.Xr watch 8
.Sh RESTRICTIONS
Only the superuser may access the
.Nm snp
devices.
.Sh BUGS
While in line mode, user input can't be seen.
No signals may be sent to the observed tty.
.Sh AUTHORS
.An Ugen J.S. Antsilevich Aq ugen@NetVision.net.il
.Sh HISTORY
The
.Nm snp
device first appeared in
.Fx 2.1 .
Clean up man page 1995-02-23 01:25:48 +00:00			`.\"`
$Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00			`.\" $FreeBSD$`
Clean up man page 1995-02-23 01:25:48 +00:00			`.\"`
Update to reflect new calling conventions 1995-02-25 20:15:20 +00:00			`.Dd February 24, 1995`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Dt SNP 4`
			`.Os FreeBSD`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh NAME`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Nm snp`
			`.Nd tty snoop interface`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh SYNOPSIS`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Fd #include <sys/snoop.h>`
			`.Ft int`
Update to reflect new calling conventions 1995-02-25 20:15:20 +00:00			`.Fn ioctl fd SNPSTTY &dev`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Ft int`
Update to reflect new calling conventions 1995-02-25 20:15:20 +00:00			`.Fn ioctl fd SNPGTTY &dev`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Ft int`
Update to reflect new calling conventions 1995-02-25 20:15:20 +00:00			`.Fn ioctl fd FIONREAD &result`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh DESCRIPTION`
Clean up man page 1995-02-23 01:25:48 +00:00			`/dev/snp? are snoop devices which allow user to attach to any tty`
			`and watch activities on it.`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00
Clean up man page 1995-02-23 01:25:48 +00:00			`To associate a given`
			`.Nm snp`
			`device with a tty to be observed, open the`
			`.Nm snp`
			`device and then use the SNPSTTY ioctl.`
Update to reflect new calling conventions 1995-02-25 20:15:20 +00:00			`The argument passed to the IOCTL is the address of a variable of type`
			`dev_t.`
delete doubled words, e.g.: "the the" -> "the" 1996-10-05 18:37:31 +00:00			`By setting the value of the variable pointed to -1, the user may detach`
Update to reflect new calling conventions 1995-02-25 20:15:20 +00:00			`the snp device from a tty.`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Pp`
			`The SNPGTTY ioctl returns information about the current tty attached to`
			`the open`
			`.Nm snp`
			`device.`
			`.Pp`
			`The FIONREAD ioctl returns a positive value equal to the number of characters`
			`in a read buffer.`
			`Special values defined are:`
			`.Bl -tag -width SNP_TTYCLOSE`
			`.It Dv SNP_OFLOW`
Fix a bunch of spelling errors in a bunch of man pages. 1996-01-30 13:52:50 +00:00			`device overflow occured, device detached.`
Clean up man page 1995-02-23 01:25:48 +00:00			`.It Dv SNP_TTYCLOSE`
			`tty not attached.`
			`.It Dv SNP_DETACH`
			`.Nm snp`
Fix a bunch of spelling errors in a bunch of man pages. 1996-01-30 13:52:50 +00:00			`device has been detached by user or tty device has been closed`
			`and detached.`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh SEE ALSO`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Xr pty 4 ,`
Sort cross references. 1996-12-26 16:16:37 +00:00			`.Xr sio 4 ,`
			`.Xr watch 8`
Clean up man page 1995-02-23 01:25:48 +00:00			`.Sh RESTRICTIONS`
			`Only the superuser may access the`
			`.Nm snp`
			`devices.`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh BUGS`
Clean up man page 1995-02-23 01:25:48 +00:00			`While in line mode, user input can't be seen.`
Fix a minor grammar bug. 1995-02-28 00:24:47 +00:00			`No signals may be sent to the observed tty.`
.Sh AUTHOR -> .Sh AUTHORS according to mdoc specs. Use .An/.Aq. 1998-03-12 07:31:21 +00:00			`.Sh AUTHORS`
			`.An Ugen J.S. Antsilevich Aq ugen@NetVision.net.il`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh HISTORY`
Clean up man page 1995-02-23 01:25:48 +00:00			`The`
Snoop device stuff * Make snoop see the output in tty ECHO mode * Allow writing to observed tty (very funny) * Fix and extend watch util. * Fix and update manpages 1995-02-27 19:45:57 +00:00			`.Nm snp`
Use the .Fx macro for FreeBSD references for releases prior to 2.0. Use the .Tn macro for generic FreeBSD references. Cleanup other formatting problems noticed while making the above changes. 1997-03-21 20:14:15 +00:00			`device first appeared in`
			`.Fx 2.1 .`