molly-guard(8) [debian man page]

MOLLY-GUARD(8)							  [FIXME: manual]						    MOLLY-GUARD(8)

NAME

       molly-guard - guard against accidental shutdowns/reboots

SYNOPSIS

       shutdown [-hV] [--molly-guard-do-nothing] [-- script_options]

       halt [-hV] [--molly-guard-do-nothing] [-- script_options]

       reboot [-hV] [--molly-guard-do-nothing] [-- script_options]

       poweroff [-hV] [--molly-guard-do-nothing] [-- script_options]

DESCRIPTION

       molly-guard attempts to prevent you from accidentally shutting down or rebooting machines. It does this by injecting a couple of checks
       before the existing commands: halt, reboot, shutdown, and poweroff. This happens via scripts with the same names in /usr/sbin, so it only
       works if you have /usr/sbin before /sbin in your PATH!

       Before molly-guard invokes the real command, all scripts in /etc/molly-guard/run.d/ have to run and exit successfully; else, it aborts the
       command.  run-parts(1) is used to process the directory.

       molly-guard passes any script_options to the scripts, and also populates the environment with the following variables:

       o   MOLLYGUARD_CMD - the actual command invoked by the user.

       o   MOLLYGUARD_DO_NOTHING - set to 1 if this is a demo-run.

       o   MOLLYGUARD_SETTINGS - the path to a shell script snippet which scripts can source to obtain settings.

       molly-guard prints the contents of /etc/molly-guard/messages.d/COMMAND or /etc/molly-guard/messages.d/default to the console, if either
       exists. This is due to /etc/molly-guard/run.d/10-print-message.

GUARDING SSH SESSIONS

       molly-guard was primarily designed to shield SSH connections. This functionality (which should arguably be provided by the openssh-server
       package) is implemented in /etc/molly-guard/run.d/30-query-hostname.

       This script first tests whether the command is being executed from a tty which has been created by sshd. It also checks whether the
       variable SSH_CONNECTION is defined. If any of these tests are successful, test script queries the user for the machine's hostname, which
       should be sufficient to prevent the user from doing something by accident.

       You can pass the --pretend-ssh script option to molly-guard to pretend that those tests succeeds. Alternatively, setting
       ALWAYS_QUERY_HOSTNAME in /etc/molly-guard/rc causes the script to always query.

       The following situations are still UNGUARDED. If you can think of ways to protect against those, please let me know!

       o   running sudo within screen or screen within sudo; sudo eats the SSH_CONNECTION variable, and screen creates a new pty.

       o   executing those command in a remote terminal window, that is a XTerm started on a remote machine but displaying on the local X server.

       You have been warned. You can use the --molly-guard-do-nothing switch to prevent anything from happening, e.g.  halt
       --molly-guard-do-nothing.

OPTIONS

       --molly-guard-do-nothing
	   Cause molly-guard to print the command which would be executed, after processing all scripts, instead of executing it.

       -h, --help
	   Display usage information.

       -V, --version
	   Display version information.

SEE ALSO

       shutdown(8), halt(1), reboot(8), poweroff(8).

LEGALESE

       molly-guard is copyright by martin f. krafft. Andrew Ruthven came up with the idea of using the scripts directory and submitted a patch,
       which I modified a bit.

       This manual page was written by martin f. krafft madduck@madduck.net.

       Permission is granted to copy, distribute and/or modify this document under the terms of the Artistic License 2.0

COPYRIGHT

       Copyright (C) 2008 martin f. krafft

[FIXME: source] 						   Apr 19, 2008 						    MOLLY-GUARD(8)

Check Out this Related Man Page

Scope::Guard(3) 					User Contributed Perl Documentation					   Scope::Guard(3)

NAME

       Scope::Guard - lexically-scoped resource management

SYNOPSIS

	   my $guard = guard { ... };

	     # or

	   my $guard = scope_guard &handler;

	     # or

	   my $guard = Scope::Guard->new(sub { ... });

	   $guard->dismiss(); # disable the handler

DESCRIPTION

       This module provides a convenient way to perform cleanup or other forms of resource management at the end of a scope. It is particularly
       useful when dealing with exceptions: the "Scope::Guard" constructor takes a reference to a subroutine that is guaranteed to be called even
       if the thread of execution is aborted prematurely. This effectively allows lexically-scoped "promises" to be made that are automatically
       honoured by perl's garbage collector.

       For more information, see: <http://www.drdobbs.com/cpp/184403758>

METHODS

   new
	   my $guard = Scope::Guard->new(sub { ... });

	     # or

	   my $guard = Scope::Guard->new(&handler);

       The "new" method creates a new "Scope::Guard" object which calls the supplied handler when its "DESTROY" method is called, typically at the
       end of the scope.

   dismiss
	   $guard->dismiss();

	     # or

	   $guard->dismiss(1);

       "dismiss" detaches the handler from the "Scope::Guard" object. This revokes the "promise" to call the handler when the object is destroyed.

       The handler can be re-enabled by calling:

	   $guard->dismiss(0);

EXPORTS

   guard
       "guard" takes a block and returns a new "Scope::Guard" object. It can be used as a shorthand for:

	   Scope::Guard->new(...)

       e.g.

	   my $guard = guard { ... };

       Note: calling "guard" anonymously, i.e. in void context, will raise an exception.  This is because anonymous guards are destroyed
       immediately (rather than at the end of the scope), which is unlikely to be the desired behaviour.

   scope_guard
       "scope_guard" is the same as "guard", but it takes a code ref rather than a block.  e.g.

	   my $guard = scope_guard &handler;

       or:

	   my $guard = scope_guard sub { ... };

       or:

	   my $guard = scope_guard $handler;

       As with "guard", calling "scope_guard" in void context will raise an exception.

VERSION

       0.20

SEE ALSO

       o   B::Hooks::EndOfScope

       o   End

       o   Guard

       o   Hook::Scope

       o   Object::Destroyer

       o   Perl::AtEndOfScope

       o   ReleaseAction

       o   Scope::local_OnExit

       o   Scope::OnExit

       o   Sub::ScopeFinalizer

       o   Value::Canary

AUTHOR

       chocolateboy <chocolate@cpan.org>

COPYRIGHT

       Copyright (c) 2005-2010, chocolateboy.

       This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.

perl v5.16.2							    2010-05-16							   Scope::Guard(3)

Linux and UNIX Man Pages

molly-guard(8) [debian man page]

Check Out this Related Man Page