#!/bin/bash

PATH="$PATH:/bin:/sbin";
export PATH;
let gw=255-$1

net_file=/etc/network/interfaces
host_file=/etc/hostname

# change ip address and gateway of the UML
cat $net_file | sed "s/address 192.168.1.*/address 192.168.1.$1/" > $net_file
cat $net_file | sed "s/gateway 192.168.1.*/gateway 192.168.1.$gw/" > $net_file

# change hostname of the UML
echo uml_woody_$1 > $host_file

#reboot the UML
reboot

exit 0;


the above is the content of the shell script, /bin/setip written by me.

i found that SOMETIMES after i execute the script remotely, the file
/etc/network/interfaces will be totally cleared, which is not my
purpose. But, SOMETIMES it works very well.


anyone knows what's the problem?

actually i use a perl script the remotely execute the shell script i mentioned above.
here's the content of the perl script, config_net.pl :

#!/usr/bin/perl

$| = 1;

use Net::SSH::Perl;
use Net::SCP::Expect;

die "Usage: $0 LAST_OCTECT\n" if (!$ARGV[0]);

$oldip = '192.168.1.127';
print "Running /bin/setip $ARGV[0]\n";

while ($error = Rpc($oldip, "/bin/setip $ARGV[0]")) {
print "UML not up yet. $error\n";
sleep 2;
}

###############################################################################

sub Rpc {
my ($host,$cmd) = @_;
my $ssh;
print "Starting SSH\n";
eval { $ssh = Net::SSH::Perl->new($host, ['debug' => 'yes',]); };
if ($@) {
return "Failed to connect\n$@";
}
print "Logging into $host\n";
$ssh->login('root', 'root');

my ($stdout, $stderr, $exit) = $ssh->cmd($cmd);
print "Output: $stdout\n";
print "Error: $stderr\n";
return $exit;
}


is the problem lying in this one, or in the shell script??

Jimmy

moreover, they way i use config_net.pl to remotely execute /bin/setip is like:

$config_net.pl uml_number

where uml_number is a number like 11