topic Re: Perl SSH::Perl Module in Operating System - HP-UX

Perl SSH::Perl Module

David Bellamy — Tue, 10 Apr 2007 15:26:21 GMT

Hello Gurus, I need a little assistance.
I'm trying to develop a GUI monitor application for my operations using Perl/TK. This app will monitor all our HPUX systems. I'm having a little problem with the Net::SSH
module. The problem is that all commands that I issue with this module writes to STDOUT. but i need it to write to a variable so that i can manipulate the data. I have tried redirecting STDOUT in my script to write to a file, which works ok but then i can't change STDOUT back so I can open up the file and manipulate the date. attached is the script I writtened any help will be appreciated.

Re: Perl SSH::Perl Module

Court Campbell — Tue, 10 Apr 2007 15:35:51 GMT

never used the module but according the the perldoc the cmd method returns the stdout, stderr, and exit status. From the synopsis:

use Net::SSH::Perl;
my $ssh = Net::SSH::Perl->new($host);
$ssh->login($user, $pass);
my($stdout, $stderr, $exit) = $ssh->cmd($cmd);

hope that answers your question.

Re: Perl SSH::Perl Module

David Bellamy — Tue, 10 Apr 2007 15:52:10 GMT

Sorry it's the Net::SSH module and it doesn't use the stdout,stderr,exit variables.
Also the Net::SSH::Perl module take to long authenticated.

Re: Perl SSH::Perl Module

Court Campbell — Tue, 10 Apr 2007 16:38:00 GMT

i see that now, sorry.

Re: Perl SSH::Perl Module

James R. Ferguson — Tue, 10 Apr 2007 19:05:03 GMT

Hi David:

Perl's 'select' should help you. Consider this:

#!/usr/bin/perl
use strict;
use warnings;
my $log = '/tmp/mylog';
open(FH,">",$log) or die "Can't open '$log': $!\n";
print "This goes to your terminal (STDOUT)...\n";
my $oldfh = select(FH);
print "...but this goes to the log file...\n";
select($oldfh); #...back to STDOUT...
print "...and this you see on your terminal, again\n";
1;

The 'select' returns the currently selected output filehandle, and if another filehandle is supplied, it sets that one as the current output default. Thus, a write or a print without a filehandle argument defaults to this filehandle.

Regards!

...JRF...

Re: Perl SSH::Perl Module

Ralph Grothe — Wed, 11 Apr 2007 07:51:33 GMT

Hi David,

I have to admid to never have used Net::SSH
as I consider it somewhat redundant because it is more or less only a wrapper around the ssh command.
But it has a more palatable interface than doing the forking and piping with standard Perl IPC techniques.
So I just have looked up the POD of Net::SSH
http://search.cpan.org/~ivan/Net-SSH-0.08/SSH.pm
only to discover that it already comes with a
sshopen2() function for pretty straight forward access to STDIN and STDOUT.
Please, see the example in the POD.
If you are also interested in STDERR use sshopen3(), which gives you even handles to three pipes.

Re: Perl SSH::Perl Module

David Bellamy — Thu, 12 Apr 2007 11:46:44 GMT

Thanks to all. Ralph thanks the answer was in front of me all the time and i wasn't seeing it.