Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r255261: watch: Do not mess up the tty modes on early error.

Record the initial state earlier, so it is always safe to restore it.

One way this happens is if watch(8) is started by a user that does not have
access to /dev/snp. The result is "staircase effect" during later commands.

PR: bin/153052

MFC r232780 and r232781:

Fix whitespace.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Convert the snp(4) driver to use cdevpriv.

Now we have a single /dev/snp device node, which can be opened by
watch(8) multiple times. Even though snp(4) will be dead as of next
week, it's nice having this in SVN, because:

- We may want to MFC it to RELENG_7.
- By the time we fix snp(4) again, it's already there, existing watch(8)
binaries should already work.

Just like bpf(4), I'm adding a symlink from snp0 to snp to remain binary
compatible.

Allow watch(8) to use more than 10 snp* devices. This limitation was purely
due to the way watch(8) looks for available snoop devices.

PR: bin/118286
Submitted by: Mykola Zubach <zuborg@advancedhosters.com>
Reviewed by: rwatson, csjp, imp (all a long time ago)
Approved by: imp (mentor) (long time ago)
MFC after: 1 week

Close the tty file descriptor once we're done with it.
Use O_NONBLOCK when opening the tty device.

Suggested by: bde
Submitted by: ru

Restore the ability to detach from a tty via SIOCSTTY and document
recent changes in a manpage.

Reviewed by: cognet

Open the tty device and pass the fd for SNPSTTY.

MFC after: 3 days

By default, the watch utility will attempt to open /dev/snp0, if
another process already has /dev/snp0 open, the snp(4) will return
EBUSY, in which case watch will try to open /dev/snp1..9. Currently
watch does not check errno to see if the failure was a result of EBUSY.

This results in watch making futile attempts to open snp0..snp9 even
though devices may not exist or the caller does not have permissions
to access the device.

In addition to this, it attempts to setup the screen for snooping even
though it may not ever get an snp device.

So this patch does two things
1) Checks errno for EBUSY, if open(2) fails for another reason
print that reason and exit.
2) setup the terminal for snooping after the snp descriptor has
been obtained.

Approved by: bmilekic (mentor)

Remove constant which makes the assumption that the length of
_PATH_DEV will never change. In the un-likely event that _PATH_DEV
should ever change, watch(8) would have broke because of a
mis-generated device name.

Approved by: bmilekic (mentor)
Pointed out by: Yvan Boily

Userland signed char fixes for PPC build. Problems were using a char
return for getopt() and comparing to -1, ditto with fgetc() and EOF,
and using the kg_nice value from <sys/user.h>

Submitted by: Stefan Farfeleder <stefan@fafoe.narf.at>
Reviewed by: obrien, bde (a while back)
Tested lightly on: ppc, i386, make universe

Use __FBSDID over rcsid[]. Protect copyright[] where needed.

The FIONREAD sysctl operates on an int *, not a size_t *.

Reviewed by: dd

Add break's to case blocks.

PR: bin/41511
Submitted by: Daniel Hagan <dhagan@acm.vt.edu>

de __P
ANSI functions
minor knf

#include <time.h> for the definition of time functions instead of
depending on namespace pollution 2 layers deep in <sys/stat.h>.

Add an -f option which allows one to specify a snp device to use.
Previously, watch would always use the first device it could
successfully open, but this isn't always desired. Specifically, it
may not be desired during debugging (of snp), or if a particular snp
device has different permissions (which makes since after snp.c 1.64).

o When "-n" is used with watch, it disables the use of <control-X> to
change terminals being watched. This change makes watch pass the
<control-X> through to the terminal if it's not being intercepted--
previously, the keypress would simply be dropped.

Automatically load the "snp" module if it isn't already present.

Add prototypes, staticize, constify, don't shadow global variables and
functions, remove an unused function, and silence other assorted
warnings.

Set WARNS=2.

Add `_PATH_DEVZERO'.
Use _PATH_* where where possible.

Add missing .El.
-Wall cleaning.

Fix warning: return type of `main' is not `int'

$Id$ -> $FreeBSD$

Use err(3).

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

Removed old bogus prerequisite <sys/select.h>. Cleaned up #include mess.

1. change tty handling from sgttyb to termios,
2. fix a potential buffer oflow,
3. makes watch(8) conform to sysexits(3).

Not a strong 2.2 candidate even if it would be nice.

Reviewed by: joerg, imp

Remove breakage of 1.8.2.2, choose slightly better character for quit.

Use RAW, not CBREAK

I have added a '-n' flag to the watch(8) command. This option
disables the ability to interactively select a new tty. I have also
removed a check for uid == 0 because it gets in the way of using suid
mode based access control. Watch (8)is only runnable by root, so this
does not really change things much.

Closes PR#2131

Submitted-By: adrian@virginia.edu

Properly save and restore the terminal characters!

Map ^C and ^\ (INTR and QUIT) to ^Q so that you can actually send these
guys to a watched process. Useful if you're monitoring someone who's
started doing something you'd really like them to stop immediately. :)
Suggested by: Phillip White <philw@megasoft.tic.ab.ca>

Add setlocale LC_TIME

Add missing ospeed initialization

Remove trailing whitespace.

same

Update to use new calling conventions

This is watch - programm to work with /dev/snp,
it still lacks manpage-i will commit it today later.
For now to test try: watch [ttyname] :)