[ILUG] don't ya just hate it when...

[Fergal Daly]

Yeah forgot about that but there are other dangerous commands that you could
use this with, shutdown, halt, reboot, service. Also you could make a
/bin.safe which you can put into your path ahead of /bin so that the bootup
sequence is unaffected but your interactive use of these commands is.

If you wanted to get a bit fancier you could write it in C, (statically
linked etc.) and check whether it's being run interactively - is STDIN a
terminal? - if so, check the hostname, if not just execute the real command.
The only time this runs into trouble is when the program behaves differently
depending on it's executable name but you can spoof the executable name with
execve() so that's grand too,

Fergal


On Thu, May 17, 2001 at 04:15:06PM +0100, Glen Gray wrote:
> Won't that break the bootup sequence ?
> 
> Glen
> 
> On 17 May 2001 16:08:37 +0100, Fergal Daly wrote:
> > Why not wrap your "dangerous" commands in a safety program, so that
> > 
> > init 1
> > 
> > becomes
> > 
> > init hostname 1
> > 
> > and if hostname isn't the name of the machine you're currently on then it
> > tells you, otherwise it just throws away the first argument and runs
> > 
> > init.real 1
> > 
> > Here it is in perl. Just rename the original to have a .real on the end and
> > put this script in instead. It won't work with suid programs, you'd need
> > some C for that and my hangover is really starting to kick in...
> > 
> > #! /usr/bin/perl -w
> > 
> > use strict;
> > 
> > my $host = shift;
> > 
> > my $real_host = `/bin/hostname`;
> > 
> > chomp $real_host;
> > 
> > if ($host ne $real_host)
> > {
> >   warn "You're on '$real_host' ya spanner\n";
> >   exit 1;
> > }
> > 
> > # $0 contains the name we were called with
> > 
> > my $real_command = "$0.real";
> > exec($real_command, @ARGV) || die "Failed to exec '$real_command': $!";
> > 
> > 
> > 
> > On Thu, May 17, 2001 at 03:36:36PM +0100, Breathnach, Proinnsias (Dublin) wrote:
> > > I've often found that changing the colour of an xterm (and / or prompt)
> > > depending on the machine / user was a good way of not doing silly stuff ...
> > > like root = red on black, easy enough to read, but obvious enough not to rm
> > > -rf on ...
> > > 
> > > P
> > > 
> > > > -----Kate Said:-----
> > > >  I got sick of that years ago, and changed the prompt on the box to set
> > > > the hostname and user name in the PS1, and in the titlebar of the window
> > > > (just in case). Well worth doing.
> > > 
> > > 
> > > -- 
> > > Irish Linux Users' Group: ilug at linux.ie
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> > 
> > -- 
> > 
> > -- 
> > Irish Linux Users' Group: ilug at linux.ie
> > http://www.linux.ie/mailman/listinfo/ilug for (un)subscription information.
> > List maintainer: listmaster at linux.ie
> 
> 
> -- 
> Irish Linux Users' Group: ilug at linux.ie
> http://www.linux.ie/mailman/listinfo/ilug for (un)subscription information.
> List maintainer: listmaster at linux.ie

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