README
======

wall-notify is a simple program which receives all messages written by wall
and passes them to a notification program via stdin. It's designed for
simplistic desktop environments (like tiling window managers) or GNU
Screen/Tmux sessions to notify the user about important messages like reboots.
It was inspired by KDE's knotify.

wall messages are either directly created by root with the `wall` command or
sent by other programs like `reboot`, `shutdown` or other processes like NFS
to warn users when the NFS server terminates.

Optionally X11 can be used to automatically terminate wall-notify when the
current X11 session terminates, i.e. when the user logs out. See below.

wall-notify is licensed under GPL 3 (or later).


DEPENDENCIES
------------

- C89 compiler
- libutempter or utmpx.h (utmpx.x requires a setgid utmp binary)

- optional: X11 headers and library, necessary for X11 support


INSTALLATION
------------

    ./configure && make && make check

If libutempter is not available, the binary must be setgid utmp:

    chgrp utmp src/wall-notify
    chmod g+s src/wall-notify


USAGE
-----

To dump all wall messages to stdout use:

    ./src/wall-notify cat

All arguments passed to `wall-notify` are used when execing the process, e.g.
to replace all spaces with underlines use:

    ./src/wall-notify sed 's/ /_/g'

To display the messages with `xmessage` use:

    ./src/wall-notify xmessage -file -

However this will display '^M' (carriage-return) and other control characters
in the message. For a simple wrapper script which removes those, see
`contrib/message-helper`:

    ./src/wall-notify contrib/message.sh xmessage -file -

The shell is not used when running the program.


If X11 support is compiled in then the '-X' option can be used to terminate
wall-notify automatically when the X session quits. This is useful when
wall-notify is started in `.xinitrc` and should quit when the X session ends,
i.e the user logs out:

    ./src/wall-notify -X cat


By default only messages from root are displayed. To allow messages from other
users (which includes `rwalld` in most setups) the option '-m' must be used.


BUGS
----

Doesn't work on OpenBSD which has no support for utmpx.h.

If you find any bugs not mentioned in this document please report them to
<simon@ruderich.org> with wall-notify in the subject.


AUTHORS
-------

Written by Simon Ruderich <simon@ruderich.org>.


LICENSE
-------

wall-notify is licensed under GPL version 3 or later.

Copyright (C) 2014-2015  Simon Ruderich

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

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