Unable to store the command output from Net::SSH2. Please help.

Venerable Monks,

I am trying to collect the ouptut of a command that is run after logging in to a NAS Array through SSH.

The command, nas_server -list gives the statuts of the NAS Array. I am trying the following script to do it. For some reason, its not capturing the actual command output of the command in the @output array even after stating my @output = $chan->exec('nas_server -list'); It seems to capture the value 1, which I presume corresponds with the successful status of the command being executed.

Here is the complete script

#!/usr/bin/perl;
use Modern::Perl;
use 5.014;
use Net::SSH2;

my $nasip = '127.0.0.1'; #Actul IP is different. 

my $user = 'user';

my $pass = 'passwd';

my $ssh = Net::SSH2->new();

$ssh->debug(1);

say "Connecting to $nasip";

$ssh->connect("$nasip") || warn "$!";

$ssh->auth_password("$user","$pass");

my $chan = $ssh->channel();

my @output = $chan->exec('nas_server -list');

say "output is: @output";

$chan->close();

[download]

And here is the output. The IP given in the example is 127.0.0.1, but I am actually using a different IP to login to the NAS Array

Connecting to 127.0.0.1
libssh2_channel_open_ex(ss->session, pv_channel_type, len_channel_type
+, window_size, packet_size, ((void *)0) , 0 ) -> 0x11353dc
output is: 1
Net::SSH2::Channel::DESTROY
Net::SSH2::DESTROY object 0x9b745c
[download]

Firstly, I know very rudimentary Perl and I am back here after almost a year, so if any mistakes in the script above please do forgive me. Thanks a lot to vdubjunkie, because If not for his node Net::SSH2 woes, I wouldn't even have written the above script.

The NAS Array (Network Attached Storage Array) is an EMC Storage Array - NS960. I am running the script from a Windows 2003 host on which Perl Version 5.14.2 is installed.

Kindly request you please guide me to a site where a detailed tutorial for the Net:SSH2 Module is given. I did go through the perldoc, also googled, but didn't find anything that I could understand. :(

Perlpetually Indebted To PerlMonks

Comment on Unable to store the command output from Net::SSH2. Please help. Select or Download Code
Re: Unable to store the command output from Net::SSH2. Please help. by salva (Monsignor) on Oct 28, 2012 at 17:19 UTC
`Net::SSH2::Channel::exec` does not capture the output of the remote command, it just launches it. You have to use the `read` method afterward to retrieve the output. On Unix/Linux systems Net::OpenSSH is far easier to use. Or there is also Net::SSH::Any that can work on top of Net::SSH2 and provides a simpler to use API, though it is still not a mature module.	[reply] [d/l] [select]
Re: Unable to store the command output from Net::SSH2. Please help. by syphilis (Canon) on Oct 29, 2012 at 09:21 UTC
Based on what works for me on Windows (connecting to a linux server) you should be able to do: `my @output; $chan->blocking(1); $chan->exec('nas_server -list'); while (<$chan>) {push @output, $_} print for @output;` [download] Cheers, Rob	[reply] [d/l]
Re: Unable to store the command output from Net::SSH2. Please help. by perl514 (Monk) on Oct 29, 2012 at 14:54 UTC
Hi Salva, Thanks for the update, but I cannot download any extra modules, because the system from which I am running the perl scripts is not connected to the internet. I am using DWIM Perl and it only has Net::SSH2. Hi Syphilis (Rob), I did try your suggestion, but that still doesnt work. All I got is whats shown below `Connecting to xxx.xxx.xxx.xxx libssh2_channel_open_ex(ss->session, pv_channel_type, len_channel_type +, window_size, packet_size, ((void *)0) , 0 ) -> 0x1137a74 Net::SSH2::poll: timeout = 250, array[1] - [0] = channel - [0] events 1 - libssh2_poll returned 1 - [0] revents 128 Net::SSH2::Channel::DESTROY Net::SSH2::DESTROY object 0x9b7404` [download] Any suggestion to a good tutorial for Net::SSH2 will really help. Perlpetually Indebted To PerlMonks	[reply] [d/l]
Re^2: Unable to store the command output from Net::SSH2. Please help. by salva (Monsignor) on Oct 29, 2012 at 15:06 UTC
Well, Net::SSH::Any has no dependencies besides Net::SSH2, so it should be pretty easy to install, even without internet access. Just unpack its `lib` directory in the right place under the DWIN directory and you are done!	[reply] [d/l]
Re: Unable to store the command output from Net::SSH2. Please help. by perl514 (Monk) on Nov 06, 2012 at 18:56 UTC
Hi Tried using the Net::SSH::Any module, but it's not doing what I expected. I am going wrong somewhere. I am trying to ssh into the VMWare Guest OS (CentOS 6.2). Before trying the script, I pinged and ensured that its working. I am also able to putty into the VMWare Guest OS, but not able to use the script for some reason. Given below is the script `#!/usr/bin/perl use Modern::Perl; use Net::SSH::Any; my $host = '192.168.247.101'; my $user = "perl514"; my $passwd = "redhat"; my $ssh = Net::SSH::Any->new ($host, user => $user, password => $passw +d); my @output = $ssh->capture2("ls -l"); say "@output";` [download] And here is the output. The cursor blinks for a while so it appears that it could be running the command, but returns the following error `Use of uninitialized value $output[0] in join or string at anyping.pl +line 10.` [download] Basically I want to capture the output of the ls -l command in the @output. Perlpetually Indebted To PerlMonks	[reply] [d/l] [select]


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Unable to store the command output from Net::SSH2. Please help.

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