SSH and Scripting

[Anonymous Monk]

Hi Monks

I am trying to SSH into a remote machine and execute a shell script. So far I can access the machine and I can run basic administrative commands such as, pwd, ls ,df -h, but when I attempt to use sh, perl, or any of the SGE commands (qsub, qstat) my script fails. Ideally I want to use the SGE commands directly, but I would be happy if I can get a shell script to run and thereby accomplish what I need to do (check status of a job and hopefully one day actually submit a job). Any help is greatly appreciated.

Below is my existing script:

use warnings;
use strict;
use Perl::Critic;
use Net::SSH::Perl;
use Net::SSH::Perl::Key::RSA;
use Class::ErrorHandler;

my $server="400.800.400.800"; #not a real IP address
my $port="22";
my $username="snoopy";
#my $command="df -h"; #this worked
#my $command="ls"; #this worked
#my $command="sh status.sh"; #Received error Use of uninitialized valu
+e $stdout in string at ssh.pl 
#my $command="/usr/bin/sh status.sh"; #Received error Use of uninitial
+ized value $stdout in string at ssh.pl 
#my $command="qstat"; #Received error Use of uninitialized value $stdo
+ut in string at ssh.pl line 
my $command="pwd"; #this worked

my $ssh = Net::SSH::Perl->new("$server", protocol=> 2, port=>"$port", 
+identity_files=>["/location/of/my/identity/files/file"]);

$ssh->login($username);
my($stdout, $stderr, $exit) = $ssh->cmd("$command");

print "$stdout";

[Bloodnok]

You are sure that the ssh config allows you to run the failing commands, aren't you ?

Also, as anony monk has already said, try printing the value of $stderr to get at the error from the ssh session e.g. print $stdout ? $stdout : $stderr;.

You could also try pre-fixing status.sh with $HOME i.e. $HOME/status.sh since . is not normally on the path for an ssh login because of it's inherent insecurity, ensuring that the command is set up within single quotes in order to ensure that it is expanded at the remote end $command = '/usr/bin/sh $HOME/status.sh';.

[NetWallah]

Try printing out $stderr ...