#!/usr/bin/perl -w
#
use strict;
use Getopt::Long;

#;;;;;;;;;;;;
# tested on solaris 7 and 8
# change ip and hostname with submitted arguments from cmd
#
# change router ip as well if new ip is on different subnet
#;;;;;;;;;;;;

my ($opt_newip,$opt_oldip,$opt_newhost,$opt_oldhost);
my @ipFiles     = qw(/etc/hosts);
my @routerFiles = qw(/etc/defaultrouter);
my @hostFiles   = qw(/etc/hosts /etc/nodename /etc/hostname.hme0
                   /etc/net/ticlts/hosts /etc/net/ticots/hosts
                   /etc/net/ticotsord/hosts
                  );

GetOptions(
    'newip=s'   => \$opt_newip,
    'oldip=s'   => \$opt_oldip,
    'newhost=s' => \$opt_newhost,
    'oldhost=s' => \$opt_oldhost,
);
# none of the arguemnts supplied
if (!$opt_newip && !$opt_oldip && !$opt_newhost && !$opt_oldhost) {
    printHelp();
    exit;
}
# catch the case that the arguments are not supplied by pair
if ( ($opt_newip xor $opt_oldip) || ($opt_newhost xor $opt_oldhost) ) {
    print "Error: need pair of arguemnts\n";
    printHelp();
    exit;
}

if ($opt_newip && $opt_oldip) {
    doReplace($opt_newip,$opt_oldip,\@ipFiles);
    # extract 1.2.3. from 1.2.3.4
    # comparing extracted subnets,
    # change router ip if subnets are different
    if ( (my ($subNew)=$opt_newip=~/(.*)\.\d+/) &&
         (my ($subOld)=$opt_oldip=~/(.*)\.\d+/)
       ) {
            doReplace($subNew,$subOld,\@routerFiles) unless ($subNew eq $subOld);
         
    }
}
if ($opt_newhost && $opt_oldhost) {
    doReplace($opt_newhost,$opt_oldhost,\@hostFiles);
}

sub doReplace {
    my ($new,$old,$files) = @_;
    my $regex="s/\Q\b$old\E/$new/g";
    foreach my $f (@$files) {
        my $cmd = "perl -i -pe '".$regex."' $f";
        print "cmd: $cmd\n";
        #print "\t $f changed\n" unless (system($cmd));
    }
}

sub printHelp {
    print "Change hostname and/ip in all config files for Solaris\n";
    print "Change router ip in config files as well base on supplied IPs\n";
    print "eg: script -oldip [ip] -newip [ip] -oldhost [host] -newhost [host]\n";
}